Classification and Detection of Errors in Minimally Invasive Surgery

Abstract

Purpose:

To provide a comprehensive review of the classification of surgical errors as well as general measures to detect and prevent their occurrence.

Materials and Methods:

Search in PubMed, Medline, and Cochrane library with combination of the key words: Endoscopy or surgical procedures, minimally invasive, and medical error. Relevant articles were selected by three senior authors involved in minimally invasive surgery (MIS).

Results:

Error is an unintended healthcare outcome caused by a defect in the delivery of care to a patient. Surgical errors are common and account for half of all hospital adverse events (AEs). Urology is the fifth specialty in decreasing order of AE. Errors may be classified according to the place where they occur (co-face or systemic), to the outcomes (near miss, recovery, and remediation). A specific classification for errors in MIS has also been described (Cushieri), depending on the step of the surgical procedure in which they occur. Each classification serves definite purposes, and no one can be definitive over the others. No classification has been applied so far to urology. Detection through appropriate reporting is the basis for prevention.

Conclusion:

Surgical errors represent a significant proportion of all medical error. Multiple classifications exist, depending on the purposes they are intended to serve. A classification based on the place of occurrence of the errors has been adopted in the medical system; however, when referring to MIS, a finer classification is proposed.

Introduction

T he tendency to err is intrinsic to biologic human behavior and performance. It is impossible to completely eliminate errors from medical practice or to predict the moment of occurrence.^1,2 In the current medicosocial scenario, multiple factors contribute to an increasing awareness of the phenomenon. The striking report, “To Err is Human,”³ published in 1999, and subsequent cases and summaries provoked a powerful reaction in medical society. This landmark report estimated that among the errors resulting in death in the hospitals in the United States, the surgical ones accounted for most of the deaths. The same year, the Accreditation Council for Graduate Medical Education recognized that one of the core competences, “Patient Care and Practice-based Learning,” included surgical management and elaborated a program to warrant patient safety. This program culminated in the recommendation in 2002 to use simulators in the certification of training programs.⁴ In subsequent years, the amount of published literature on the subject increased dramatically in an attempt to better understand the nature and causes of errors, to plan for their avoidance, and to design remediation measures to minimize their consequences.

The last decade has been characterized by unprecedented development of minimally invasive techniques and extensive media diffusion of the corresponding advantages and mistakes, the former sometimes premature and the latter frequently overstressed.

Urology, with a high caseload of minimally invasive surgery (MIS) is one of the three specialties, together with general surgery and gynecology, in which endoscopic surgical errors have been critically analyzed by third parties and institutional safety measures have been advised for training and recertification during the professional career.⁵

Classification of surgical errors is confusing, however, mainly because terminology is complex and not yet standardized. The aim of the present review is to provide a clear overview of: (1) Classification of errors; (2) errors and outcomes; and (3) detection of errors and prevention of errors, with special focus on MIS.

Materials and Methods

A search was performed in three electronic databases (PubMed, Embase, Cochrane library) focusing on the topic surgical errors in MIS. The literature search strategy based on MeSH terms was the following: Endoscopy or surgical procedures, minimally invasive, and medical error, with limits set for the publication language (English) and time period (1989–2010). Retrieved citations (PubMed n=1916, Embase n=15, Cochrane library n=2) were combined. After excluding duplicates and citations in abstract forms, titles and abstracts of full articles were checked manually for relevance by three senior authors who are involved in MIS (JR, JdlR, MPL). Based on their judgment, 57 articles were considered eligible to be included for the purposes of this review.

Results

Surgical errors are common and frequently lead to clinical impact.⁶ Almost 20 years ago, the Harvard Medical Practice study showed that operative adverse events (AEs) account for 48% of all AEs. They occurred in 2% of hospitalized patients and were preventable 74% of the time.^6,7 Later on, data were confirmed in a retrospective review of a representative sample of Utah and Colorado hospitals admissions.⁸ The investigators found that of all AEs reported, 66% were surgical, the annual incidence was 3%, and 54% of the AEs were preventable. Transurethral resection of the prostate and transurethral resection of bladder tumors were the seventh most common operation type with higher risk of AEs with an overall annual incidence of 5.5%; most (overall 3.9%) were preventable.

More recently, prospective surveys as well as a meta-analysis of retrospective studies support previous data confirming that approximately 50%to 60% of all reported AEs occur in the operating room setting or around a surgical procedure.^9
–11 Among the different surgical specialties, urology was the fifth in decreasing order of AEs with an incidence of 3.7% of all AEs.¹²

Definition of error

The Patient Safety Foundation defines error as an “unintended health care outcome caused by a defect in the delivery of care to a patient.”¹³ In the literature, however, different terms are used that fulfill this concept (Appendix 1).

Any member of the healthcare team, in any setting, may commit an error. There are, however, errors that are unique to the surgical community because of the singular nature of the surgical procedure.

An error may be a commission (wrong action), an omission (correct action not performed), or an execution (correct action performed in a wrong way).¹³

Classification of errors

The literature on classification of surgical errors is confusing. A main reason is that most of the classifications have been developed in the so-called man-machine systems that were designed initially in industrial settings. There is a good extrapolation from the industrial to the surgical setting, however. Basically, errors can be classified according to the place they occur and the phase of the medical process in which they occur. A further classification is related to the consequences (outcomes) they entail. Depending on the phase of the working process in which they are enacted, active medical errors can be of a diagnostic, treatment, prevention, and miscellaneous nature (Leape's classification).¹⁴

The place in which error happens (proximal or distal to the patient) and the nature (active/passive or commission/omission) of error are closely related. To clarify taxonomy and simplify nomenclature, the Cuschieri classification integrates place and nature.^2,13 Errors in MIS interesting the surgical treatment phase deserve specific comments as well as the different outcomes.

Each classification serves definite purposes, and each one of them is better used in the appropriate context.

According to place. As in industry, in medicine, two apparently conflicting preventive approaches to the origin of errors have been formulated¹⁵: The classical person-approach, blaming the individual for most of the responsibility and the newer system-based approach that in an equally extreme position discharges the individual almost from any responsibility and attributes the error to the system. According to this approach, errors originate from a person's or from a system's action/omission. Depending on the place in which they occur, errors are classified as:

Co-face error. Also known as coal-face, frontline, sharp-end, and distal error. These types of errors occur at the sharp-end or direct contact between the patient and the surgeon. They are active errors,¹⁵ specific to the surgical performance, and refer to the actuarial occurrence of the error. An example could be cutting the ureter during a pelvic lymph node dissection. This definition views errors as arising primarily from aberrant mental processes such as forgetfulness, inattention, poor motivation, carelessness, negligence, and recklessness.¹⁶ Co-face errors are subdivided into: Input errors (of knowledge and perception), intention errors (mind-set), and execution errors (psychomotor).²

Systemic errors. Also named proximal errors or “of root cause.”¹ These errors occur at the blunt-end and are only partially applicable to surgery.¹³ Systemic errors consists of an unfortunate chain of wrong commissions, omissions, or executions (frequently a combination of more than one) where one leads to or sustains the following event. Systemic errors are provoked by outside events over which the surgeon may or may not have control (eg, absence of a defogging sponge available, fogged lens, incorrect identification of the borders of the renal vein, and inadvertent cutting of the renal vein). They occur as a sequence of events and involve the different layers of the healthcare system that ultimately affect the person holding the instrument. The systemic error approach takes virtually all blame away from the surgeon and relies on the system for its defective defensive layers.² This new point of view represents an initial overreaction to the co-face errors responsibility. Systemic errors are subdivided into: (1) Coherence and goal conflicts, (2) poor leadership, (3) inadequate teamwork, (4) inadequate training (including continued professional development of staff), (5) inadequate resource allocation, 6) unclear protocols, briefings, and procedures, (7) lack of evidence-based practice, (8) nontransparent culture, (9) overwork, (10) lack of quality assurance measures, and (11) inadequate system for detection of poor performance.²

According to the type of errors. The above nomenclature corresponds well with the classification described by Reason where active errors will be the equivalent to co-face errors and the latent errors to systemic ones.^13,15 Reason's “Swiss cheese” model integrates both approaches, illustrating how accidents may arise from a combination of person-system set of factors.¹⁵ In this model, defensive layers are seen like slices of Swiss cheese with many holes. The different holes represent either active failures (co-face errors) committed by people directly in contact with the patient or by the system (latent/systemic errors) in design, organization, training, and maintenance (eg, sleep deprivation because of work overload, poorly designed tools, unclear protocol, inadequate training, etc.). Holes are dynamic in nature, and they are continuously opening, shutting, and shifting their location. The presence of holes in any particular “slice” might not cause an AE. If the holes in many layers momentarily line up, however, a trajectory of accident opportunity appears.

Yet in surgery, a substantial proportion of the responsibility lies exclusively with the surgeon because of the specific nature of the treatment offered. The surgeon is the one who ultimately applies the correct surgical maneuvers with the highest quality of cognitive and psychomotor skills. During surgery or an interventional procedure, there is an actual action or decision that only the surgeon commits or takes, being in itself an error (eg, cutting the ureter, using a wrong surgical instrument for dissection or cutting). Distal errors are not only technical-operative ones, but may also be enacted during the preoperative or postoperative period (eg, diagnosis, patient selection for a specific minimally invasive technique, management, prevention).¹ The assignment of responsibility of such an event to the system would be inappropriate.

In essence, any single error lies between these two classes (co-face and systemic). The various elements that underpin a safe surgical practice aim to minimize both the person and the factual error^16,17 (Table 1).

Table 1.

Safe Surgical Practice Components ²

Safe surgical practice components
• Organizational structure
• Strategic control of healthcare delivery
• Harmonic teamwork
• Effective leadership
• Application of the principles of evidence-based medicine
• Surgical proficiency
• Continuous professional development of all staff
• Access to healthcare information technology
• Well-embedded incident reporting

Technical errors during minimally invasive surgery. Basically, errors that occur during MIS have the same nature as medical and surgical errors. Nevertheless, one can argue that as MIS has specific connotations and working conditions that may differ from open surgery (eg, absence of three-dimensional view, longer instruments, higher difficulty in acquiring skills, hand-eye-foot coordination), the spectrum of errors may vary (eg, hypercapnia is AE-specific of laparoscopy). Sir Alfred Cuschieri¹⁶ nicely depicted a detailed analysis of the generic mechanisms underlying operative technical errors during endoscopic surgery. This classification describes errors in relation to the step of the surgical procedure in which they occur and is applicable on an individual basis. Errors in MIS are classed as: (a) Cognitive errors of judgment, (b) procedural errors, (c) execution errors, (d) misinterpretation errors, (e) errors from misuse of energized dissection systems, and (f) missed iatrogenic injuries.

Cognitive errors of judgment concern the clinical judgment and decision-making in relation to the feasibility of the procedure with respect to the operator's proficiency level and the particular operative findings of each case. These kinds of errors are closely related to the operator's experience. For example, a cognitive error of judgment in laparoscopy is represented by the timing of conversion to open surgery. As such, elective conversion is associated with less morbidity than emergency conversion.¹⁸

Procedural errors occur when the component steps of an intervention are not executed in the right sequence or particular steps are omitted. They are very common even among fully proficient surgeons because of lack of standardization of most endoscopic procedures with task analyses.

Execution (psychomotor) errors are committed by the operator who performs the procedure but executes it in a suboptimal manner. A recent analysis of critical incidents in general surgery showed that 47.7% of active errors (at the sharp-end) were execution failures and 46% were knowledge-based errors.¹⁹

Misinterpretation errors represent one of the main causes of iatrogenic injuries. They are unique to MIS, because the surgeon relies on a displayed image to operate. Because the surgeon's interface with the operative situation is limited to the displayed image, there is a great risk for iatrogenic injuries to neighboring tissues (also named garden path errors).²⁰ Laparoscopic and endoscopic surgery requires spatial awareness skills to perceive depth on a two-dimensional screen, and the surgeon may encounter a cerebral mapping problem because of the spatial separation between displayed anatomy on screen and actual manipulation.²¹ Furthermore, the phosphor screen pulsation in cathode ray tube monitors is a source of misinterpretation errors from visual strain.^22,23 This results from the degradation of eyeball movements because of the fixation/refixation necessary for scanning and interpreting displayed images.

Errors from misuse of energized dissection systems occur when energy systems are used incorrectly or in suboptimal conditions. In fact, putative damage of proximal important structures in the operative field has been described even with the use of the safest systems.

Missed iatrogenic injuries refers to injuries that are overlooked during the procedure or identified late postoperatively.

Various factors that can lead to errors by affecting surgeons' performance during an intervention have been recognized, such as knowledge-in-context and mind-set problems.²⁴ Knowledge-in-context factors refer to incorrect (buggy) knowledge, correct but inert knowledge, and oversimplified application of possessed knowledge. There is no question about the first case. Knowledge, however, is a necessary but not sufficient condition for expertise. The latter is situation-relevant knowledge-dependent. In other words, knowledge should be organized in such a way that it can be accessible and applicable according to the specific situation needs.²⁵ As far as oversimplifications are concerned, they may lead to errors because of misconceptions.²⁶ Mind-set problems refer to defects in attention control, loss of situational awareness (perception of an emerging situation that may lead to an AE unless appropriate action is taken), and fixation (cognitive lock-up). The latter is the inability to revise strategy as dictated by the evolving conditions.²⁷ The surgeon remains fixed on his initial erroneous assessment of the situation, usually because of excessive stress.

Furthermore, errors can be distinguished according to the cognitive stages at which they occur following the three-level behavior model by Reason and Rasmussen.^15,28,29 Reason differentiates three types of human failures: Slips, lapses, and mistakes. Slips occur in the execution stage of an action sequence during the skills-based behavior and in MIS refer to the lack of force perception, velocity, degrees of freedom, and displacement of tissue because of poor dynamics and ergonomy of the instruments. Lapses occur in the storage phase between planning and execution or during rule-based behavior (RBB). Because RBB precludes the use of a protocol, any anatomy variation or differences with the protocol obliges the surgeon to change actions and may prompt a lapse-like error. Mistakes are defined as failures in the judgment or planning of an action and the process after it.¹⁵ These last errors happen during the most challenging knowledge-based behavior. The mental complex process of building up a three-dimensional internal image can easily lead to complications (mistakes) when anatomic or pathologic variations are present in the patient. Each specific level of behavior will necessitate a different level of training.²⁹ A proposal of integration of Cuschieri classification with the cognitive stages is presented in Table 2.

Table 2.

Integration of Cushieri Classfication of Technical Errors During Minimally Invasive Surgery and Reason-Rasmunssen Classification

Cuschieri	Cognitive stages of behavior	Human failure
Cognitive errors of judgment	KBB	Mistake
Procedural	RBB	Lapse
Execution	SBB	Slip
Misinterpretation	SBB	Slip
Misuse of energized systems	RBB	Lapse
Missed iatrogenic injuries	RBB	Lapse

KBB=knowledge-based behavior; RBB=rule-based behvior; SBB=skills-based behavior.

In laparoscopic surgery, there is one more and very specific error, the perceptual error. This error is most likely committed by more experienced surgeons as they build up a cognitive image of the anatomy and have specific expectations during surgical procedures. The surgeon anticipates the anatomic structures and the following steps of the operation. When anatomy is not properly seen because of the narrow and limited view of the endoscopic camera, the surgeon “fills in the gaps.” In those cases where anatomy differs from the preconceived model, error might occur without identification. The surgeon has then to recuperate the procedure to find the steps leading to the error after the consequences appear.^30,31

Errors and outcomes

Outcomes are independent of the nature of the error or the phase of the procedure in which it happens.² Basically, when an error is committed, it can be recognized or not. Only when recognized can it be remediated. While it is true that a nonrecognized error may lead to a complication more frequently than a recognized one, unrecognized errors do not always result in a complication. There are three possible outcomes according to the severity of their consequences: near miss (or no harm), recovery (with or without sequelae), and remediation.³⁰

Near miss. The definition of near-miss error (or “close call” or “barely miss”) is borrowed from air traffic control. It is an adverse or unplanned event that did not result in injury, illness, or damage, although it might potentially have serious safety-related consequences.³² These errors are subjected to root-cause analysis, extremely frequent, and it is estimated that they occur 300 to 400 times more often than an AE.² Near-miss errors do not result in harm either because when they occur they are recognized and subsequently corrected or because in spite of not being recognized (and not corrected), they do not lead to complication.³³ Near misses are because of capacity limitation of the system, clerical error, equipment failure, clinical error, and also because of patient failure. Overall, near-miss errors do not result significantly in complications although they occur in a high percentage of medical episodes (up to 56%). They are rarely if ever reported. An example might be clipping of a lower pole artery during laparoscopic pyeloplasty with no postoperative sequelae. Some authors propose a third type of near-miss error; that is, when the AE occurs, one of more of the systems fails to detect and correct and harm is sustained but falls short of the worst possible outcome.³³

The surgeon must pay specific attention to those minor mistakes and state them in an anonymous report to identify different or recurrent errors in the same type of operation.

Recovery. When an error occurs with immediate identification and correction (recovery), the patient still has the possibility of recovering with minimal or no consequences or a complication may arise. An example would be cutting into the rectum during laparoscopic radical prostatectomy with immediate closure by endoscopic suturing. The consequences might be a longer hospital stay for the patient and a specific diet but without complications (ie, sepsis and colostomy). Conceptually, recovery errors provide suboptimal care and may impair full recovery.

Remediation. The unrecognized errors that lead to consequences after operation (remediation) are often reported and discussed in interdisciplinary conferences. Still, in the current legal scenario, the surgeon is mainly blamed for this complication, not only because of commission but also for the lack of recognition. Frequently, this type of error makes full recovery impossible.

Recent surveys in surgery show that the majority of AEs (range 65%–85%) are included in the category of remote probability of causing harm or minor harm or are near misses resulting in no harm for the patient with only a minority (range 22%–12%) being categorized as major errors resulting in harm to the patient.^9
–11

Detection and prevention of errors

Although it is not possible to eliminate errors from surgical practice, they are preventable.¹⁰ Detection and analysis of errors are complex processes that are otherwise unavoidable in order to design measures to prevent them and to increase the safety of the system.

Detection. Underreporting of AEs ranges from 65% to 90% annually.^34
–36 Errors can be recognized by quantitative analysis of macro datasets and also by qualitative microanalysis of small-scale studies. These data provide a good reflection of the practice on a daily basis. Supervisory and informal discussion and near-miss content are important information for improving clinical care.³⁷

A key point in the detection of errors is the information available in the clinical record and the efficient report of incidents, including the near misses. In surgery, the errors should be detected has soon as possible to keep the patient's risk in an “as low as realistically possible” state.² Medical record review, however, is limited in understanding and quantifying errors and up to 33% of the errors are only verbally discussed but not properly documented. Approximately a quarter of the errors may be uncertain and their report influenced by subjectivity.³⁷

Severe incidents should be reported to the Hospital Safety Committee and disclosed to patient and relatives.² Report of near misses relies on a voluntary basis and is supported by a nonblame culture.

There are multiple national and institutional initiatives at all professional levels involved in patient care to develop error report systems. All of them are based on voluntary, confidential, and—most of them—anonymous reports (near-miss registries). A good example is the Patients Safety Reporting System developed by the United States Department of Veterans Affairs and the National Aeronautics and Space Administration, based on voluntary and confidential reports.³⁸

A group of anesthetists from Switzerland developed an anonymous Critical Incident Reporting System (CIRS^©) based on Internet technology.³⁹ CIRS is currently used on a national basis in Switzerland. About 200 critical incidents have been reported during its operational span of 3 years showing that human factors such as tiredness, haste, wrong decisions, etc., were responsible for 64% of the incidents and insufficient communication for 19% of them. On the other side, human intervention and skill prevented 75% of critical incidents. The report elegantly shows that although the surgeon takes direct responsibility for more than half of the critical events because of personal approaches, he/she also prevents even more accidents because of experience and proficient action.

A recent prospective voluntary report of 24 hours critical incident after anesthesia showed an incidence of 0.8% critical incidents in a year period. From them, 71.5% of patients completely recovered but 28.5% of the incidents resulted in mortality. Incidents occurred maximally in children, in American Society of Anesthesiologists 1 patients, in general surgery cases, in emergency cases, and during daytime. Incidence was also higher in the operating theater and under general anesthesia. The cause of the incidents was related to anesthesia, patients, and surgery in 43%, 37.5%, and 17% of cases, respectively. Mortality was mostly attributed to patient risk factors (59.4%) followed by anesthesia (25%) and surgery (9.4%).⁴⁰

Focusing on surgery,⁴¹ an anonymous and confidential interview of a representative sample of surgeons at three teaching hospitals in the United States showed that the consequences of errors might be serious. In this report, 33% of the errors resulted in permanent disability and 13% in patient death. Injuries related to operation or invasive method accounted for 77% of those incidents, and 13% were deemed unnecessary or inappropriate surgical or invasive procedures. Two-thirds of the incidents arise during the intraoperative phase of surgical care and 75% in elective surgical care.

Analysis. A critical analysis of these incidents follows, establishing the basis to adopt safety measures resulting in “error-tolerant systems.” Two good models show the different factors related to an AE and their critical analysis: The onion model⁴² and the artichoke model by Bogner.⁴³ Those models incorporate all systemic and personal factors that are closely related to the activity at the patient's side in the center. The detection of an error can be seen as peeling off the layers of an onion or an artichoke. Each layer represents an individual factor related to the following layer.

The type of procedure and patient characteristics are important factors in analyzing surgical errors.¹⁰ When incidents are categorized according to contributing factors to analyze causes,⁴⁴ system factors contribute to the error in 86% of the cases but also cognitive factors contribute in the same percentage.⁴¹ Inexperience or lack of competence, communication breakdown, and excessive workload or fatigue are the most common systemic factors involved. The most common cognitive factors attributed to the causality of incidents were error in judgment and failure of vigilance.⁴¹ Although this work does not give an insight into the real incidence, it shows that the subjective assessment is quite accurate and consistent with previous reports⁸: Most of the errors were the result of a chain of events spanning more than one phase of care and not the result of an individual failure.

A recent analysis of the Veterans Health Administration shows that the three most common root causes of surgical errors are communication, time-out-problems, and nonstandardization in 21%, 17.5%, and 10% of cases, respectively. Human factor and schedule problems, followed by education and training are responsible for 8% of surgical errors.¹¹

The majority of surgical AEs involve a technical error. In an analysis of surgical malpractice claims, among those in which injuries from error were detected, 52% involved technical errors with half of them causing permanent disability and 16% resulting in death. Manual error was the cause in 65% of the injuries; 9% were errors of judgment, and 26% were linked to both causes. A minority of technical errors involved advanced procedures needing special training. The majority (73%) involved experienced surgeons performing routine operations. Patient-related complexities (emergency procedures, difficult or unexpected anatomy, and previous operations) contributed to 61% of technical errors and technology or systems failures contributed to 21% of errors.⁴⁵

Prevention. Improvement of surgical care may be achieved by adopting “error-tolerant operating systems” based on recent progress in cognitive psychology, human factors, and human reliability.¹ The understanding of the particular nature of errors in the surgical setting with the aid of observational clinical human reliability assessment may contribute to designing the best way of prevention (surgical error reduction systems) or remediation and lead to a balance of the surgeon's position toward responsibility (personal or systemic).¹⁷

Prevention should involve all the steps in the error process and address correction at an individual and at a systemic level. As mentioned, most of the errors or AEs occur as a concatenation of individual and systemic factors, and prevention will only be effective when implementation measures target both causes in parallel.

At individual level. (a) Cognitive errors of judgment and execution errors: Surgeons are expected to reach a certain level of cognitive and psychomotor proficiency for the required tasks. Surgeons should maintain a dynamic of continuous training, deliberate practice, and maintenance of attention. Inclusion of the different modes of theoretical and mechanical training in the core curriculums and in the continuous medical education programs plays an important role as well as adequate supervision.

(b) Procedural errors: Surgical protocols including the MIS techniques need to be standardized. Standardization is a prerequisite for quality assurance of any kind of surgical interventions.¹⁶ Patient factors that deviate from protocol should be discussed beforehand to develop operational strategy.

(c) Misinterpretation errors: Laboratory skills training and proficiency-integrated programs are most likely to result in a decrease in interpretation errors.

(d) Errors from misuse of energized dissection systems: Team control in the safety of the systems in use. Checklists and regular revision and maintenance of instruments should be mandatory.

(e) Missed iatrogenic injuries: Adequate report of all operative events and complications reported together with preoperative and postoperative control measures.

The Agency for Healthcare Research and Quality (AHRQ) in their report on the effect of healthcare working conditions on patient safety has been finding evidence that preventable complications are lower when complex technical procedures are performed by physicians who conduct them frequently and that the duration and experience of the health professionals are associated with better patient outcomes for some types of clinical care.⁴⁶ One of the most recent funded projects of the AHRQ is: “Do simulators reduce the time to learn surgical skills?”⁴⁷ overstressing the possible importance of the subject.

The inclusion in the training and in continuing medical education of error models (ie, training in complication, complication conference, education on events prevention, surgical simulation) helps to recognize, remediate, and avoid or at least minimize the occurrence by optimizing the surgical environment.⁴⁸

Because the surgeon is the one who is most responsible for errors, it is important to have a system to assess the quality of surgical performance. One example is the Observational Clinical Human Reliability Assessment (OCHRA).⁴⁹ This system provides objective, complete tracking of errors related to performance of a specific operation. It also identifies hazard zones, where technical errors occur most commonly and are likely to jeopardize clinical outcome. The surgeon's performance is videotaped and analyzed afterward using a specific error mode (Table 2). Each step of the operation is carefully observed to record committed errors and their external modes. Although OCHRA is an ideal human factor research tool and assesses very well the performance of a specific operation, its inclusion as a model to reduce surgical error in current practice is difficult. The system (OCHRA) requires intensive labor and a lot of resources and expertise, most of them lacking in the current medicosurgical context.⁴⁹

At systemic level. Measures to be taken at the systemic level involve mainly the organizational structures.

Ineffective team communication is at the root of medical and surgical failure.^10,50 To prevent it, teamwork training, feedback on performance, and continued data collection and analysis to reach continuous improvement is needed.⁴⁸

An open culture, free of blame, and in which everyone shares and contributes in a responsible manner is of utmost importance to prevent errors in the operating room. Near miss can be prevented by a change in practice at the different stages of care (diagnostic, admission to hospital, operative and perioperative, first outpatient control).

A “must” step to reduce errors is standardization. Although it is a difficult task to find a correct standard for use by all surgeons, efforts must be made to lead to a safer environment in the operating room. Cuschieri¹⁶ presents an interesting surgical error reduction system (SERS) for laparoscopic operations. In this system, once a specific operation is selected, experienced surgeons, who have shown their knowledge and skills in terms of clinical outcome and surgical-related morbidity, are invited to participate in the SERS process. First, complete video recordings are obtained and reviewed by expert surgeons, a quality assurance team, and a human factor specialist identifying the component steps and differences. The quality assurance team creates a detailed report including task description and the differences observed. This report is sent to the expert surgeons who performed the operation to comment on it. A meeting with all members involved in this process follows to find a consensus about the standards of the operation's performance. The result would be a benchmark to assess the quality of execution for the specific operation at various hospitals.

To identify errors in a specific operation, a standardized categorization of the different steps of the surgical procedure and the facts considered as errors is needed. Joice and coworkers⁵¹ described a useful categorization based on external error modes (Embrey, 1986)⁵⁰ (Table 3).There are two different groups: Interstep errors and intrastep errors. Interstep errors correspond to the categories 1 to 6 in the external error mode list. They refer to omissions or rearrangements of the correct steps within the surgical procedure. On the other hand, the intrastep errors correspond to the last categories, 7 to 10. They involve the correct execution of an individual step and analyze the surgeon's motor skills—eg, using too much or too little force.

Table 3.

External Error Modes/Surgeon Performance

Pattern of failure	Definition
Procedual errors
1	Step is not done
2	Step is partially completed
3	Step is repeated
4	Step is done in addition
5	Second step is done instead of first step
6	Step is done out of sequence
7	Step is done with too much force, speed, depth, distance, time, or rotation
Executional errors
8	Step is done with too little force, speed, depth, distance, time, or rotation
9	Step is done in wrong orientation, direction, or point in space
10	Step is done on/with the wrong object (or plane)

Adapted from Joice P, et al. Appl Ergon, 1998.⁵¹

The majority of errors recorded were intrastep errors associated with the motor control of instruments. The frequency of interstep errors in this study showed a high number of 39% of the total number of errors. This can apply to a failure in the education of the surgeon or the surgeon performed a practice he thought to be the best in this case.⁵¹

Comments

Some considerations of errors deserve critical comments. The first is the acknowledgment that errors enacted in the operating room represent at least half of the overall hospital errors. Being epidemiologically correct, this figure does not take into account the window of opportunities for an error to occur. As the number of interventions that a given patient receives and the number of persons involved in the surgical pathway is likely higher than in an internal medicine ward, the ratio of incidents/number of treatment activities, albeit unknown, would probably be lower.² Chances are that, strictly speaking, the surgical environment might be safer than that of other medical specialties. Nevertheless, surgical incidents seem to be more prone to be divulged because of the magnitude of the consequences and because frequently the operating room is the battlefield between team and organization priorities (patient safety vs administrative issues).⁵²

The second is that all human errors, including those medical/surgical, have the same primary dichotomous mechanism of occurrence. The division of errors into proximal or co-face and distal or systemic has proven functional in industrial systems.²⁹ Hospital organizational and operative systems and more specifically the operating room environment, have evolved into complex scenarios in which not only sophisticated and delicate technology is increasingly used but also a plethora of individuals play roles in the different steps of the process.

Some recent articles have been challenging the current systemic approach to errors and suggest that individuals are still the main cause of error.⁵³ Although it seems quite understandable to consider that system variables precede errors in the chain, the individual always mediates their effect on performance. The systemic approach takes into account the latent factors, variables, and communication that either support effective performance or hinder it, increasing the likelihood of error occurrence.^54,55 The fact that any single surgical error lies between the two categories does not excuse the individual from taking the appropriate measures to minimize them. On the other side of the spectrum, institutional measures need to be implemented to overcome individual deficits.

All the above mentioned applies sharply to MIS, where dependence on energized sources is higher than in open surgery, surgeon adequate ergonomy is harder to reach, and where the operator's vision depends on a camera driven by others.

A safe and accurate prospective report is the basis for an analysis of the mechanism involved in error. There are good examples of voluntary and confidential reports of errors and incidents, such as the Patients Safety Report System, developed by the United States Department of Veterans Affairs together with the National Aeronautics and Space Administration.³⁸ Whether these reports should be mandatory or voluntary remains a matter of sensible debate.⁵⁶ It is clear that they should include not only major errors but also near misses, irrespective of their consequences, because those are much more frequent than major errors. A nonblame, open, transparent, and loyal attitude should be encouraged in surgical departments to assess and prevent any kind of error. On the importance of reporting the near misses, we only have to mirror industry where this kind of minor event is rigorously analyzed in an attempt to define the root causes.⁵⁷

The causes of errors vary in the literature, depending on the method used to report and analyze. Systemic and cognitive deficiencies, with equal share, seem to be at the root when surgeons are directly interviewed,⁴¹ while a formal committee analysis, including different specialists and psychologists, showed that human factor is only responsible for a minority of incidents.¹¹

This apparent disparity leads to a capital question: Does one classification suffice to categorize all identified errors? A recent work shows that a protocol integrating different systems, 2 classifications with an analysis of the root causes, adequately categorized all the critical incidents in general surgery.¹⁹

Last, the authors think it is worthwhile to stress the almost nonexistent references to errors and AEs in urology. With the view that MIS represents a major percentage of the current surgical activity in our specialty, it would be logical to think that detection and analysis systems will provide an insight into specific errors in this type of surgery. Preventive measures would be easier to perform and apply in a relatively limited specialty such as ours.

Two important issues related to errors: Specialist recertification and surgical skills training have not been treated in this review. Both might become compulsory in a short period. Adequate documentation of errors will be crucial in recertification and surgical skills acquisition (by means of structured training programs) of outmost importance in reducing surgical errors.

Conclusions

Medical errors can be basically classed as person approach or as systemic error, although most of them fall in a combined category. In endoscopy and laparoscopy, errors can be furthermore classed as cognitive (of judgment), procedural, executional, of misinterpretation, because of the misuse of energized dissection systems, and missed iatrogenic injuries. A proper understanding of errors' mechanisms and anonymous reporting, including near misses, will identify measures to prevent them. Error-tolerant operating systems integrating cognitive psychology and human factors should lead to minimizing surgical errors.

Footnotes

Acknowledgment

Dr. Charalampos Mamoulakis thanks the Alexander S. Onassis Public Benefit Foundation for a grant to attend a clinical fellowship program at the Academic Medical Center, Department of Urology, Amsterdam, the Netherlands.

Disclosure Statement

No competing financial interests exist.

Abbreviations Used

Appendix 1. Recommended Patient Safety Terms Related to Surgical Practice *

Active error. Error associated with the performance of the “frontline” operator of a complex system and whose effects are felt almost immediately.

Adverse event. An unintended injury caused by medical (surgical) management rather than by a disease process. Any injury caused by medical care.

Patient safety incident. Preferred to the adverse event in the United Kingdom because terms such as adverse, error, or mistake suggest individual causality and blame (NPSA terminology 2004).

Critical incident. Occurrence that is significant or pivotal in either a desirable or undesirable way.

Root cause. An initiating cause of a causal chain that leads to an outcome or effect of interest.

Latent failure (error). Less apparent failures of organization or design that contribute to the occurrence of errors or allowed them to cause harm to the patient.

References

Cuschieri

. Medical errors, incidents, accidents and violations. Minim Invasive Ther Allied Technol, 2003; 12:111–120.

Cuschieri

. Nature of human errors: Implications for surgical practice. Ann Surg, 2006; 244:642–648.

Kohn

, Coorigan

, Donaldson

. To Err Is Human: Building a Safer Health System. Washington, DC: National Academy Press, 1999.

Society of American Gastrointestinal Endoscopic Surgeons (SAGES). Integrating advanced laparoscopy into surgical residency training. Surg Endosc, 1998; 12:374–376.

Risico's minimal invasieve chirurgie onderschat. Kwaliteitssysteem voor laparoscopische operaties ontbreek. Inspectie voor de gezondheidszorg. Den Haag, November 2007; IGZ07-55.

Brennan

, Leape

, Laird

et al. Incidence of adverse events and negligence in hospitalized patients: Results of the Harvard Medical Practice Study I. N Engl J Med, 1991; 324:370–376.

Leape

, Brennan

, Laird

et al. The nature of adverse events in hospitalized patients: Results of the Harvard Medical Practice Study II. N Engl J Med, 1991; 324:377–384.

Gawande

, Thomas

, Zinner

, Brennan

. The incidence and nature of surgical adverse events in Colorado and Utah in 1992. Surgery, 1999; 126:66–75.

Gurjar

, Roshanzamir

, Patel

, Harinath

. General surgical adverse events in a UK district general hospital–lessons to learn. Int J Surg, 2011; 9:55–58.

10.

Stone

, Bernstein

. Prospective error recording in surgery: An analysis of 1108 elective neurosurgical cases. Neurosurgery, 2007; 60:1075–1082.

11.

Neily

, Mills

, Eldridge

et al. Incorrect surgical procedures within and outside of the operating room. Arch Surg, 2009; 144:1028–1034.

12.

de Vries

, Ramrattan

, Smorenburg

et al. The incidence and nature of in-hospital adverse events: A systematic review. Qual Saf Health Care, 2008; 17:216–223.

13.

Satava

. The nature of surgical error. A cautionary tale and a call to reason. Surg Endosc, 2005; 19:1014–1016.

14.

Leape

. A systems analysis approach to medical error. J Eval Clin Pract, 1997; 3:213–222.

15.

Reason

. Human error: Models and management. BMJ, 2000; 320:768–770.

16.

Cuschieri

. Reducing errors in the operating room: Surgical proficiency and quality assurance of execution. Surg Endosc, 2005; 19:1022–1027.

17.

Billings

, Woods

. Human error in perspective. The patient safety movement. Postgrad Med, 2001; 109:13–17.

18.

Morgenstern

. Achilles' heel and laparoscopic surgery. Surg Endosc, 1995; 9:383.

19.

Zingg

, Zala-Mezoe

, Kuenzle

et al. Evaluation of critical incidents in general surgery. Br J Surg, 2008; 90:1420–1425.

20.

Johnson

, Moen

, Thompson

. Garden path error in diagnostic reasoning. Bolec

, Coombs

. Expert System Applications. New York: Springer-Verlag, 1988.

21.

Wade

. Frames of reference in vision. Minim Invasive Ther Allied Technol, 1996; 5:435–439.

22.

Kennedy

, Baccino

. The effects of screen refresh rate on editing operations using a computer mouse pointing device. Q J Exp Psychol, 1995; 48A:55–71.

23.

Kennedy

, Murray

. Eye movement control during the inspection of words under conditions of pulsating illumination. Eur J Cogn Psychol, 1996; 8:281–403.

24.

Cook

, Woods

. Operating at the “sharp end”: The complexity of human error. Bogner

. Human Error in Medicine. Hillsdale, NJ: Lawrence Erlbaum, 1994.

25.

Bransford

, Sherwood

, Vye

, Rieser

. Teaching thinking and problem solving: Research foundations. Am Psychol, 1986; 41:1078–1089.

26.

Feltovich

, Spiro

, Coulson

. The nature of conceptual understanding in biomedicine: The deep structure of complex ideas and the development of misconceptions. Evans

, Patel

. Cognitive Science in Medicine: Biomedical Modeling. Cambridge, MA: MIT Press, 1989.

27.

de Keyser

, Woods

. Fixation errors: Failures to revise situation assessment in dynamic and risky systems. Colombo

, Saiz de Bustamante

. System Reliability Assessment. The Netherlands: Kluwer Academic, 1990; 231–251.

28.

Rasmussen

. Skills, rules and knowledge; signals, signs and symbols, and other distinctions in human performance models. IEEE Transactions on Systems, Man and Cybernetics, 1983; 13:257–266.

29.

Dankelman

, Wentink

, Stassen

. Human reliability and training in minimally invasive surgery. Minim Invasive Ther Allied Technol, 2003; 12:129–135.

30.

Satava

. Identification and reduction of surgical error using simulation. Minim Invasive Ther Allied Technol, 2005; 14:257–261.

31.

Way

, Stewart

, Gantert

et al. Causes and prevention of laparoscopic bile duct injuries: Analysis of 252 cases from a human factors and cognitive psychology perspective. Ann Surg, 2003; 237:460–469.

32.

www.wikipedia.org/wiki/. 2010 December 12.

33.

Nashef

. What is a near miss? Lancet, 2003; 361:180–181.

34.

Feldman

, Barkun

et al. Measuring postoperative complication in general surgery patients using an outcomes-based strategy: Comparison with complications presented at morbidity and mortality rounds. Surgery, 1997; 122:711–719.

35.

Thompson

, Prior

. Quality assurance and morbidity and mortality conference. J Surg Res, 1992; 52:97–100.

36.

Brennan

, Localio

, Leape

et al. Identification of adverse events occurring during hospitalization: A cross-sectional study of litigation, quality assurance, and medical records at two teaching hospitals. Ann Intern Med, 1990; 112:221–226.

37.

Rosenthal

, Cornett

, Sutcliffe

, Lewton

. Beyond the medical record: Other modes of error acknowledgment. J Gen Intern Med, 2005; 20:404–409.

38.

Lenert

, Burstin

, Connell

et al. Federal patient initiatives panel summary. J Am Med Inform Assoc, 2009; 9,suppl:S8–S10.

39.

Staender

, Davies

, Helmreich

et al. The anaesthesia critical incident reporting system: An experience based database. Int J Med Inform, 1997; 47:87–90.

40.

Gupta

, Naithani

, Brajesh

et al. Critical incident reporting in anaesthesia: A prospective internal audit. Indian J Anaesth, 2009; 53:425–433.

41.

Gawande

, Zinner

, Studdert

, Brennan

. Analysis of errors reported by surgeons at three teaching hospitals. Surgery, 2003; 133:614–621.

42.

Engineers. Center for Chemical Process Safety. A.I.O.C. Guidelines for preventing human error on process safety. 1994.

43.

Bogner

. Safety issues. Minim Invasive Ther Allied Technol, 2003; 12:121–124.

44.

Vincent

, Taylor-Adams

, Chapman

et al. How to investigate and analyse clinical incidents: Clinical risk unit and association of litigation and risk management protocol. BMJ, 2000; 320:777–781.

45.

Regenbogen

, Greenberg

, Studdert

et al. Patterns of technical error among surgical malpractice claims: An analysis of strategies to prevent injury to surgical patients. Ann Surg, 2007; 246:705–711.

46.

Hickan

, Severance

, Feldstein

et al. The Effect of Health Care Working Conditions on Patients Safety. Evidence Report/Technology Assessment n. 74. Rockville, MD: AHRQpublication no. 03-EO31April 2003.

47.

Clancy

. Committee on optimizing graduate medical trainee (resident) hours and work schedules. www.ahrg.gov/news/sp120307.htm. 2010 May 09.

48.

Kao

, Thomas

. Navigating towards improving surgical safety using aviation-based strategies. J Surg Res, 2008; 145:327–335.

49.

Tang

, Hanna

, Joice

, Cuschieri

. Identification and categorization of technical errors by Observational Clinical Human Reliability Assessment (OCHRA) during laparoscopic cholecystectomy. Arch Surg, 2004; 139:1215–1220.

50.

Karsh

, Wiegmann

, Wetterneck

, Carayon

. Communication and systems factors might still underlie surgical complications. Surgery, 2009; 145:686–687.

51.

Joice

, Hanna

, Cuschieri

. Errors enacted during endoscopic surgery—a human reliability analysis. Appl Ergon, 1998; 29:409–414.

52.

Flin

, Yule

, McKenzie

et al. Attitudes to teamwork and safety in the operating theatre. Surgeon, 2006; 4:145–151.

53.

Fabri

, Zayas-Castro

. Human error, not communication and systems, underlies surgical complications. Surgery, 2008; 144:557–565.

54.

Ben-Tzion

, Wiegmann

, Wetterneck

, Carayon

. Communication and systems factors might still underlie surgical complications. Surgery, 2009; 145:686.

55.

Nagpal

, Vats

, Vincent

, Moorthy

. A systems approach to errors. Surgery, 2009; 145:689–690.

56.

Karlsen

, Hendrix

, O'Malley

. Medical error reporting in America: A changing landscape. Qual Manag Health Care, 2009; 18:59–70.

57.

Lamb

, Nagpal

. Patient safety. Importance of near misses. BMJ, 2009; 339:b3032.