A Study of Three-Dimensional Versus Two-Dimensional Laparoscopic Surgery in Resection of Congenital Choledochal Cyst of Children and Jejunum Roux-en-Y Anastomosis

Abstract

Background:

This study aimed to explore the clinical efficacy of three-dimensional (3D) laparoscopic surgery in the treatment of congenital choledochal cysts (CCCs) by comparing it with two-dimensional (2D) laparoscopic surgery.

Patients and Methods:

We retrospectively reviewed data of 155 pediatric patients who underwent surgical treatment of choledochal cysts between January 2014 and December 2017. We divided the patients into two groups according to the surgical method used—a 3D laparoscopic group (N = 42) and a 2D laparoscopic group (N = 113). The 3D laparoscopic group was further divided into two subgroups based on age—Group 1 (age ≤12 months, N = 11) and Group 2 (age >12 months, N = 31). We analyzed data in terms of the following characteristics: patient demographics, perioperative and follow-up conditions, and complications. Moreover, we also recorded and analyzed the surgeon's assessment on laparoscopic system usage.

Results:

Cyst excision and Roux-en-Y hepaticojejunostomy (HJ) was successfully completed in all the patients. Intergroup differences in operating time and blood loss were statistically significant. There were no significant differences between the two groups in early and late complications, such as the incidence of wound infection, HJ stricture, or adhesive ileus. There were no significant differences in the operative data and outcomes between the two subgroups of patients who underwent 3D laparoscopic treatment. Based on surgeon's assessment, the 3D laparoscopic system had better depth perception and accuracy than the 2D laparoscopic system; however, there was no difference in the adverse effect on surgeons.

Conclusions:

Compared with the traditional 2D laparoscopic surgery, 3D laparoscopic surgical resection of CCCs combined with jejunum Roux-en-Y anastomosis is a safer and more effective procedure that can shorten operative time and reduce intraoperative bleeding with no increase in surgical strain. The 3D laparoscopic surgery technique may provide a better choice for CCC operations.

Introduction

Congenital choledochal cyst (CCC), a rare congenital anomaly, presents as an extrahepatic and/or intrahepatic bile duct dilatation in children.^1,2 The etiology of CCC is still not fully understood; however, the etiological explanation of abnormal pancreaticobiliary duct junction is well established.³ According to statistics, the incidence of CCC is relatively uneven with respect to geography and sex; it is much higher in Asian countries than in Western countries and is 3–4 times higher in females than in males.^4–6 Most affected patients are diagnosed during infancy and childhood. However, with the development of prenatal care, there has been an increasing number of reports on the management of prenatally detected CCCs in the recent years.^7–9 Patients with CCC usually present with abdominal pain, an abdominal mass, jaundice, vomiting, and fever in clinical practice. CCCs can lead to higher rates of cholestasis, bile stone formation, pancreatitis, biliary hyperplasia, and tumor formation if not treated in a timely manner.^10–12

Complete cyst excision and Roux-en-Y hepaticojejunostomy (HJ) are regarded as current standard procedures for the treatment of children with CCCs.^1,13 In 1995, laparoscopic excision of cysts and reconstruction with Roux-en-Y hepaticojejunal anastomosis in a 6-year-old girl gained attention; the laparoscopic approach has been performed worldwide since.¹⁴ Many challenges and difficulties have been encountered with laparoscopic treatment during the early stages; however, with the development of medical devices and the increased clinical experience of pediatric surgeons, laparoscopic surgery has become more feasible and effective for the treatment of patients with CCCs. Laparoscopic surgery in these patients has the advantages of small incisions, less blood loss, less postoperative pain, and speedy recovery. Hence, laparoscopic treatment is gradually replacing traditional laparotomic surgical treatment in patients with CCC.^15–17

Traditional two-dimensional (2D) laparoscopy has the limitation of loss of depth perception; the surgeon must use motion parallax by moving the laparoscope using the relative position of the instruments to transform and process the 2D image into a three-dimensional (3D) image.^18,19 Recently, multiple studies have demonstrated that 3D vision significantly improves depth perception and spatial orientation during surgery, and more studies have suggested the advantage of 3D laparoscopic systems in urological, hepatic, and other surgeries.^20,21 Three-dimensional laparoscopy has been used by our well-trained surgical team at our treatment center for several years for the treatment of children with CCCs. Therefore, this study aimed to compare the efficacy and safety of the 3D and 2D imaging systems for patients with CCCs.

Patients and Methods

Patients

A total of 155 patients were retrospectively recruited; 42 patients underwent 3D surgery and 113 patients underwent 2D surgery at the pediatric surgery department of our medical center between January 2014 and December 2017. Cases of biliary tract infection and associated malformations of the abdominal organs or dysplasia were excluded. Patients were diagnosed using ultrasonography, computed tomography, magnetic resonance cholangiopancreatography, and intraoperative cholangiography. All patients had type I cysts, and there were indications for excision of the choledochal cyst and HJ without any contraindications. These patients completed the entire therapeutic course in line with standard medical procedures under the care of an experienced and skilled surgical team at our medical center's pediatric surgery department.

Before surgery, an interview was conducted between the doctors and the enrolled patients' legal guardians for informed consent, and the choice of surgical approach was ultimately determined by the legal guardians. Subsequently, informed consent was signed and documented. All procedures were performed by a single surgeon, who had accumulated extensive experience of laparoscopic surgery and mastered the key points of both 2D and 3D laparoscopic surgeries for patients with CCCs to attenuate the effects of the learning curve. The surgical team also included a senior surgeon and a resident surgeon who functioned as an assistant and a camera operator, respectively.

Methods

The following hospitalization information was analyzed for comparison between the 3D and 2D laparoscopic groups: demographics and general clinical symptoms before surgery (sex, age at the time of diagnosis and at the time of surgery, abdominal pain, tumors, jaundice, fever, and vomiting), operative details, patient outcomes (operative methods, cyst diameter, operation time, blood loss volume, intraoperative blood transfusion, drainage duration, conversion to an open procedure, and length of hospital stay), and early complications (bleeding, bile leakage, pancreatic fistula, gastrointestinal dysfunction, and wound infection). Patients were followed up at our clinic for 1, 2, 3, and 6 months postoperation and every 6 months thereafter through outpatient visits and telephone calls to monitor and record late complications, such as HJ stricture, cholangitis, adhesive ileus, reoperation, and mortality. The mean follow-up time for all the enrolled cases was 3.4 years (range: 1–5 years).

To further study the safety and efficacy of 3D laparoscopic surgery in younger patients, this group of pediatric patients was further divided into two subgroups, children ≤12 months of age (Group 1) and children >12 months of age (Group 2). The two subgroups were compared based on the operation time, blood loss volume, intraoperative blood transfusion, conversion to an open procedure, hospital stay length, and complications.

We also investigated the subjective experience of the surgeon using the 3D and 2D laparoscopic systems for patients with CCCs. Questions included self-ratings of visualization and physical symptoms such as depth perception, precision, and adverse effects (headache, eye strain, dizziness, and others). These subjective data were assessed on a Likert scale, which was graded from 0 to 4, with “0” expressing a very poor experience and “4” expressing full satisfaction.²⁰ The questionnaires were completed immediately by the surgeon after completing each laparoscopic operation.

Surgical procedures

Conventional 2D laparoscopic surgery and 3D laparoscopic surgery were performed with the Karl Storz 2D and 3D vision systems, respectively. The monitor was placed at the foot of the operating table. Only a single image was captured at a time by the 2D laparoscopy; however, the 3D laparoscope had two image sensors, and each sensor could capture images. Their signals were then processed and synchronized on the 3D monitor, which subsequently created a stereoscopic visualization. Surgeons wore passive polarizing glasses during the 3D laparoscopic procedures. The other surgical instruments were identical in both systems.

The surgical principles and procedures of the 2D and 3D groups were identical. The patient was placed in a supine position after induction of general endotracheal anesthesia. A vertical incision was made through the umbilicus and carbon dioxide pneumoperitoneum was established with a pressure of 8–10 mmHg through a catheter, which was later replaced with a 10-mm trocar. Three more 5-mm trocars were inserted along the midclavicular line, the paraumbilical area of the right rectus abdomini, and the top left rectus abdomini. The laparoscopic surgical procedures were completed according to the standard medical procedures and the main steps included the following six phases: (1) exposure of the hepatic portal, (2) cholecystectomy, (3) free and excise the cyst, (4) jejunum Roux-en-Y anastomosis, (5) retrocolic tunnel formation, and (6) the jejunum was brought up to the hepatic duct through the retrocolic route and end-to-side anastomosis between the Roux-en-Y limb and the hepatic duct was conducted with the laparoscope.

Statistical analysis

Quantitative data are presented as mean ± standard deviation, and the distribution of categorical variables is presented as percentages or frequencies. Data analysis was performed using the SPSS software version 20.0. Student's t-test and analysis of variance were used for the analysis. The chi-square test and Fisher's exact test were applied to analyze enumeration data. All parametric numerical statistical tests were two tailed. A P-value of <.05 was considered as significant.

Results

Before surgery, sex, age at surgery, cyst diameter, and general clinical symptoms, including abdominal pain, abdominal mass, jaundice, fever, and vomiting, did not show any statistically significant differences among all groups (Table 1).

Table 1.

Demographics and General Clinical Symptoms of the Patients with Choledochal Cyst

	3D laparoscopic surgery group (N = 42)	2D laparoscopic surgery group (N = 113)	P
Gender (male/female)	8/34	23/90	.857
Age at surgery (months)	32.8 ± 20.7	35.4 ± 19.9	.469
Follow-up time (years)	3.3 ± 1.0	3.5 ± 1.1	.527
Diameter of cyst (cm)	4.4 ± 1.4	4.2 ± 1.4	.409
Abdominal pain	27 (64.3)	69 (61.1)	.713
Abdominal mass	20 (47.6)	51 (45.1)	.782
Jaundice	13 (31.0)	32 (28.3)	.748
Fever	11 (26.2)	25 (22.1)	.594
Vomiting	10 (23.8)	21 (18.6)	.470

Values are expressed as the mean ± SD or n (%).

2D, two-dimensional; 3D, three-dimensional; SD, standard deviation.

Operative details and outcomes of the studied patients were as follows. The blood loss volume in the 3D laparoscopy group was lower than that in the 2D laparoscopy group (9.6 ± 4.7 mL versus 13.7 ± 6.4 mL, P < .001). The operation time in the 3D laparoscopy group was shorter than in the 2D laparoscopy group (201.9 ± 27.3 minutes versus 228.5 ± 32.8 minutes, P < .001). Detailed data are presented in Table 2.

Table 2.

Operative Details and Outcomes of the Studied Patients

	3D laparoscopic surgery group (N = 42)	2D laparoscopic surgery group (N = 113)	P
Operation time (minutes)	201.9 ± 27.3	228.5 ± 32.8	<.001
Volume of blood loss (mL)	9.6 ± 4.7	13.7 ± 6.4	<.001
Intraoperation blood transfusion	0 (0.0)	6 (5.3)	.128
Duration of drainage (days)	4.1 ± 1.2	4.1 ± 1.1	.760
Converted to an open procedure	1 (2.4)	5 (4.4)	.558
Length of postoperative hospital stay (days)	6.3 ± 2.3	7.4 ± 3.6	.069

Values are expressed as the mean ± SD or n (%).

P < .05 shows significant difference between the two groups.

2D, two-dimensional; 3D, three-dimensional; SD, standard deviation.

Compared with the 2D laparoscopy group, the percentage of early complications, such as bile leakage, pancreatic fistula, gastrointestinal dysfunction, and wound infection, was lower in the 3D laparoscopy group, but there was no statistically significant difference between the two groups (P > .05). The incidence of late complications, such as HJ stricture, cholangitis, and adhesive ileus, in the 3D laparoscopy group was also lower than that in the 2D laparoscopy group; however, there was no statistically significant difference between the groups (Table 3).

Table 3.

Comparisons of the Early and Late Complications of All Patients

	3D laparoscopic surgery group (N = 42)	2D laparoscopic surgery group (N = 113)	P
Early complications
Bleeding	2 (4.8)	3 (2.7)	.509
Bile leakage	1 (2.4)	4 (3.5)	.717
Pancreatic fistula	0 (0.0)	1 (1.0)	.541
Gastrointestinal dysfunction	1 (2.4)	3 (2.7)	.924
Wound infection	1 (2.4)	5 (4.4)	.558
Late complications
Stricture of hepaticojejunostomy	0 (0.0)	4 (3.5)	.217
Cholangitis	2 (4.8)	6 (5.3)	.891
Adhesive ileus	1 (2.4)	3 (2.7)	.924
Reoperation	1 (2.4)	4 (3.5)	.717
Mortality	0 (0.0)	0 (0.0)	—

Values are expressed as the n (%).

2D, two-dimensional; 3D, three-dimensional.

Table 4 shows the details of the patients who underwent 3D laparoscopic surgery and the comparison of operative data between Group 1 and Group 2. None of the studied indicators demonstrated statistically significant differences (P > .05).

Table 4.

Operative Data and Complications of Three-Dimensional Laparoscopic Surgery Children with Choledochal Cysts

	Group 1	Group 2	P
	Operative age ≤12 months (N = 11)	Operative age >12 months (N = 31)	P
Operation time (minutes)	183.6 ± 15.5	208.1 ± 28.0	.078
Volume of blood loss (mL)	8.7 ± 3.1	9.9 ± 5.2	.227
Intraoperation blood transfusion	0 (0.0)	0 (0.0)	—
Converted to an open procedure	0 (0.0)	1 (3.2)	.738
Length of hospital stay (days)	6.2 ± 2.9	6.4 ± 2.0	.800
Complications	1 (9.1)	4 (12.9)	.607

Values are expressed as the mean ± SD or n (%).

SD, standard deviation.

Table 5 presents the surgeon's assessment regarding utilization of laparoscopic surgery for patients with CCCs. Compared with 2D vision, 3D vision had better depth perception (P < .001) and precision (P = .018). Regarding the adverse effects, there were no statistically significant differences between the two laparoscopic methods.

Table 5.

Data Assessed by a Likert Scale Questionnaire (from 0 to 4), Which Was Completed Immediately After Each Operation

	3D laparoscopic surgery group (N = 42)	2D laparoscopic surgery group (N = 113)	P
Depth perception	2.5 ± 1.0	1.3 ± 1.0	<.001
Precision	3.6 ± 0.5	3.2 ± 0.9	.018
Adverse effect	3.3 ± 0.7	3.5 ± 0.6	.102

Values are expressed as the mean ± SD.

A higher number indicates a better subjective rating, “0” expressing very poor experience and “4” full satisfaction.

2D, two-dimensional; 3D, three-dimensional; SD, standard deviation.

Discussion

CCC, a rare anomaly of the bile ducts, manifests with disproportionate dilatation of the biliary ductal system. In 1977, CCCs were classified into five types by Todani et al., and in pediatric patients, the most common form is type I (up to 75% cases).^2,22 Surgical excision with construction of a biliary/enteric conduit remains the primary treatment for type I choledochal cysts, and early surgery is recommended due to the risk of cysts increasing in size, inflammation, or even tumor formation.

CCCs represent a therapeutic challenge for pediatric surgeons, requiring a highly skilled technique for the appropriate surgery.²³ Laparoscopic surgery could expand the size of the surgical region because the cyst wall collapses when the cyst is cut and the bile is aspirated under the laparoscope. Furthermore, the cyst anterior and lateral walls are relatively free and safe due to the presence of the hepatic artery and portal vein in the posterior wall. When shortening the distance between the laparoscopic lens and the cyst wall, vision of the operative field can be broadened several times, which allows easy and clear visualization of the surface cyst wall and its surrounding tissue. Combined use of electric coagulation and the laparoscope during the operation can effectively prevent bleeding.^24,25 Since the use of 3D laparoscopy can improve depth of perception and lead to greater accuracy and better visibility, many studies have presented the advantages of the 3D laparoscope over the traditional 2D laparoscope. Sørensen et al. conducted a systematic literature search and identified 31 randomized controlled trials that compared 3D with 2D laparoscopy; this systemic review found that approximately three-quarters of the studies reported that the 3D system reduced performance time and more than half recorded a lower rate of error than the 2D system.²⁶ There are also studies that have revealed that the 3D system has clear advantages in improving coordination, spatial awareness, and operation time when compared with the 2D system.^27,28 In our series, the 3D group had shorter operative time than the 2D group (201.9 ± 27.3 minutes versus 228.5 ± 32.8 minutes, P < .001), which can be attributed to better depth perception and clearer vision. As surgeons did not have to transform and process the 2D image into a 3D image, operation efficacy was consequently improved. Furthermore, there was less blood loss during operation in the 3D laparoscopy group (9.6 ± 4.7 mL) than in the 2D laparoscopy group (13.7 ± 6.4 mL), with a notable statistical significance (P < .001). This might relate to the better dissection and identification of vascular structures with the 3D laparoscope.

Accurate anastomosis of the hepatic duct and jejunum is a key procedure, which is related to postoperative complications.¹⁵ In our comparison of early and late complications between the 3D and 2D laparoscopy groups, the rate of complications such as bile leakage, pancreatic fistula, stricture of HJ, and cholangitis were lower in the 3D group than in the 2D group, even though there were no differences between the two groups. This is because 3D laparoscopy provided better visibility for accurate anastomosis; in this respect, our data demonstrated the safety of 3D laparoscopic surgery in patients with CCCs.

With the development of prenatal care, the number of prenatally detected choledochal cysts is increasing, and studies have reported that minimally invasive pediatric surgery, even complex reconstructive operations, can be safely performed in infants or neonates.^9,29,30 At our pediatric surgery center, the members of our surgical team, including surgeons, anesthesiologists, and nurses, had extensive experience with complex laparoscopic procedures. The 3D laparoscopy technique has been used for the treatment of patients with CCCs who are younger than 12 months. Our results revealed that there was no increase in the occurrence of complications. With 3D laparoscopic treatment, the mean length of hospital stay, rate of conversion to an open procedure, mean volume of blood loss, and mean operation time were lower in the ≤12 months group (Group 1) than in the >12 months group (Group 2), even though this was not significant (P > .05). This indicates that 3D laparoscopy can provide better depth perception and clearer vision, even within the small abdominal space and complicated structures, which means that 3D laparoscopic surgery is safe and efficient for younger patients, even for neonates and infants.

Several studies have reported better subjective experiences of surgeons with 3D visualization, such as improved depth perception and precision.³¹ However, previous studies also showed several adverse effects, including headache, dizziness, and nausea, in surgeons when using the 3D system; however, there are also studies demonstrating that these adverse effects appeared to be mainly correlated with the inferior image resolution of the earlier 3D system.^20,32 In our study, 3D laparoscopic surgery for patients with CCC could greatly enhance depth perception and surgical precision without increasing discomfort for surgeons.

Our study has several limitations. First, to attenuate the effect of the learning curve, all procedures were performed by a single surgeon, who had accumulated extensive experience in laparoscopic surgery for patients with CCCs, making this study nonreplicable. The Likert scale was completed by a single surgeon, which might have a certain subjectivity. More surgeons should be enrolled to confirm how the 3D system could improve depth perception and precision in a future study. Second, 3D laparoscopic surgery for patients with CCCs was initially practiced with experienced surgeons who had mastered 2D laparoscopic surgery for patients with CCCs. Further studies will be needed to confirm that 3D surgery has more significant advantages for inexperienced surgeons and a shorter learning curve than 2D surgery. Third, the relatively high cost of the 3D surgical system might lead to some legal guardians not accepting these surgical methods. Fourth, our research was a retrospective study and the standard randomized trial had not been designed before surgery; it was not a strict, standard randomized study. To further study the outcome of 3D and 2D laparoscopic surgeries, large-scale, multicenter, prospective clinical research should be conducted. Despite these limitations, the application of 3D laparoscopy in pediatric surgery is seldom reported, and our study might provide valuable clues and insights for pediatric surgeons.

Conclusions

The 3D laparoscopic excision of choledochal cysts with HJ can be feasibly and safely performed in pediatric patients. This method is feasible even in neonates and infants and provides satisfactory results when performed by well-trained surgeons. Furthermore, the 3D system considerably improves depth perception and accuracy without increasing pressure on surgeons. However, to further verify our findings, a prospective clinical study with a larger sample size is needed.

Footnotes

Disclosure Statement

No competing financial interests exist.

Funding Information

The study is funded by the National Key Research and Development Program of China (grant no. 2016YFE0203900).

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