Assessment of the testicular vascularity after inguinal herniotomy in children: a prospective color Doppler study

Abstract

Background

Knowing transient vascular perfusion abnormalities of testes after open inguinal herniotomy procedure is essential for the surgeon who is mainly responsible for the patient outcome.

Purpose

To assess the effect of open inguinal herniotomy procedure on the testicular blood supply in children using duplex ultrasonography (DUS).

Material and Methods

A prospective observational study included 60 boys (mean age = 9.46 ± 14.46 months; age range = 2 months–6 years) who underwent open inguinal herniotomy operation. Using DUS, the testicular volume, peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) were calculated preoperatively and one week, one month, and six months postoperatively. The pre- and postoperative measurements were compared. Statistical analysis was performed using χ² test, Fisher’s exact test, or Student’s t-test when appropriate.

Results

On physical examination, the hernias were unilateral in 57 boys and bilateral in three boys. Comparison between testicular volumes preoperatively and postoperatively showed no significant change (P > 0.05). There was a statistically significant increase of PSV and RI one week and one month postoperatively (P < 0.0001) but returned to be near to the preoperative values at six months. As regards EDV, there was a slight but non-significant postoperative increase (P > 0.05) which did not return to the preoperative value.

Conclusion

The affection of testicular vascularity postoperatively is transient and returns to be near to the preoperative values in the late postoperative period (six months postoperatively). Additionally, no significant change in testicular volume postoperatively.

Keywords

Testicular vascularity inguinal herniotomy children duplex ultrasonography

Introduction

Inguinal hernia is a common finding in infants and children and requires surgical repair in the pediatric age group (1). The incidence of inguinal hernia is in the range of 1–4.4% and is higher in infants, proportionate with the higher rate of patent processus vaginalis (2). For inguinal hernia, elective herniotomy is indicated to prevent incarceration and subsequent strangulation. This operation is often assigned to junior surgeons or operated by consultants with no specific training in pediatric surgery (3). The blood vessels and vas are at risk of injury from both the operation and the hernia as they course adjacent to hernia sac. The surgeon tries to protect them as much as possible throughout the surgery. If the blood vessels are injured, the future growth of the testis may be affected (4).

Duplex ultrasonography (DUS) is valuable in evaluating the blood flow of testes and assessing postoperative testicular circulation (4). Testicular atrophy is a common complication after inguinal herniotomy in children. The reported incidence is in the range of 1–38%. Prader’s orchidometer was broadly used to measure testicular volume in clinical practice. Nevertheless, this measurement is mostly subjective and can be imprecise. Ultrasonography can offer a suitable and correct measurement of testicular volume (5).

Several studies have been performed using DUS to assess testicular vascularization and infertility after hernia operations in the adult population, but few such studies analyzed these changes in children. Some studies indicated that all DUS parameters were influenced in the early postoperative period. However, they returned to their prior values in the late postoperative period (6). Alternatively, some reports mentioned that DUS parameters are not altered in the early postoperative period (7,8). Accordingly, we conducted this study aimed to assess the effect of the open herniotomy procedure on testicular blood supply in children using DUS.

Material and Methods

Study population

This is an observational cross-sectional study that was carried out in the period between December 2017 and December 2018. Initially, this study included 113 patients who underwent inguinal herniotomy operation during the period of the study. Inclusion criteria for this study were: (i) patients in the pediatric age group aged ≤ 12 years; (ii) patients who had normal testicular vascularity proved by preoperative DUS; and (3) patients who had an uncomplicated inguinal hernia at the time of surgery. Exclusion criteria were: (i) patients aged > 12 years (16 patients); (ii) patients who had testicular vascularity problems proved by preoperative DUS (five patients); (iii) patients who had complicated hernia at the time of surgery, e.g. irreducible, inflamed, obstructed, or strangulated hernia (seven patients); (iv) patients who had recurrent hernia or operation in the inguinoscrotal region (10 patients); (v) contralateral inguinal herniotomy (four patients); (vi) premature infants (six patients); and (vii) patients lost during follow-up (five patients). This yielded a final cohort of 60 patients. The flow chart of our study is illustrated in Fig. 1.

Ethical considerations

The present study was approved by the institutional review board. All parents or guardians of the patients were informed about the study and written informed consent was provided. The study was performed in accordance with the ethical principles of the Declaration of Helsinki.

Patient assessment

All patients were subjected to the following: (i) a complete demographic data collection, including name, age, sex, and residence, and analysis of the main complaint (inguinal swelling); (ii) a detailed present history was taken regarding the onset, duration, and course of symptoms; (iii) past history of previous operations, medications, or allergies; (iv) clinical examination, including a general examination, to assess fitness for anesthesia—local examination was focused on the site of the hernia, impulse on cough, and examination of the testes and the scrotum; (v) laboratory investigations were done for all patients, including complete blood count, alanine aminotransferase, aspartate aminotransferase, serum creatinine, coagulation profile, and serum albumin; (vi) DUS; and (vii) herniotomy.

DUS protocol

All DUS examinations were performed using a trans-scrotal approach with a high-frequency 10-MHz linear array probe (Voluson E6 B12 system). All examinations were done one week preoperatively and one week, one month, and six months postoperatively. The examinations were performed in a warm room with the patient in the supine position; the scrotum was supported in a towel laid over the thigh. We used sedation in some uncooperative children. Images of the scrotum and bilateral inguinal regions were obtained in both transverse and longitudinal planes. Color and pulsed Doppler examinations were subsequently performed and optimized at low-flow velocities to demonstrate blood flow in the testes. All scans were performed by the same examiner using the same equipment to avoid inter-observer and inter-ultrasound transducer effects on the results. The examiner was blinded to any clinical information. The following parameters were assessed preoperatively and postoperatively: (i) testicular volume: the longitudinal, anteroposterior, and transverse diameters of the testis were measured, and the testicular volume was calculated automatically using the DUS machine; (ii) peak systolic velocity (PSV) and end diastolic velocity (EDV) were calculated by the machine, recorded bilaterally for each patient, expressed in cm/s and using the angle correction along the course of the artery; (iii) resistive index (RI) was calculated as (PSV – EDV)/PSV×100. Three RI measurements were made on each testicle at an intra-testicular artery in the upper, middle, and lower testicular pole. At least four Doppler waveforms had to be obtained from a centripetal artery.

Herniotomy technique

The patients were admitted to the hospital as day cases. The operation was done under general anaesthesia. An incision was made in the skin of the inguinal crease just lateral to the pubic tubercle (1–2 cm). Next, Scarpa’s fascia was identified and incised. The hernial sac was identified in the anteromedial aspect of the cord and medial retraction of the sac revealed the underlying testicular vessels and vas deferens. The sac was then dissected and mobilized to the internal ring. Once the sac was confirmed to be empty, it was twisted on itself and transfixed with sutures then the sac was excised; closure of wound was done in layers (6). The patients were discharged from the hospital on the same day. The postoperative outcome was monitored during outpatient visits. Follow-up of the scrotal swelling and the wound was carried out. Postoperative complications including wound infection, scrotal hematoma, and recurrence were recorded.

Statistical analysis

Data were checked, entered, and analyzed by using SPSS version 20. Data were expressed as mean ± standard deviation (SD) for quantitative variable and number and percentage for descriptive variables. The preoperative volume (volume base) was compared to postoperative volume one week (volume week), one month (volume month), and six months (volume six months) postoperatively. The preoperative PSV, EDV, and RI values were compared to postoperative values at one week, one month, and six months. χ² test, Fisher’s exact test, or Student’s t-test were used when appropriate. A P value < 0.05 was statistically significant.

Results

Patients

The present study included 60 boys who underwent open inguinal herniotomy operation. The mean age was 9.46 ± 14.46 months (age range = 2 months–6 years). On physical examination, the hernias were unilateral in 57 boys (95%)—on the right side in 39 boys (61.6%), on the left side in 18 boys (30%)—and bilateral in three boys (5%). Patients’ data are summarized in Table 1. All operations were successfully completed without any significant adverse effects, just scrotal hematoma in two cases, which disappeared within one week. No reported cases of wound infection. The recurrence was reported in two cases within the period of follow-up (six months).

Table 1.

Patient data.

Data	n (%)
Age (months) (mean ± SD (range))	9.46 ± 14.46 (2–72)
Hernia laterality
Right	39 (61.6)
Left	18 (30)
Bilateral	3 (5)
Postoperative complications
Wound infection	0
Scrotal hematoma	2 (3.3)
Recurrence	2 (3.3)

Values are presented as n (%) unless otherwise specified.SD: standard deviation.

Testicular volume

Comparison between testicular volumes preoperatively and postoperatively showed no significant change (P > 0.05) as shown in Table 2 and Fig. 2.

Table 2.

Comparison between testicular volume preoperatively and one week, one month, and six months postoperatively.

	Volume	Mean ± SD	Paired t	P
One week	Base^*	0.7792 ± 0.39526	1.14	0.25
One week	1 week	0.7406 ± 0.22576	1.14	0.25
One month	Base^*	0.7792 ± 0.39526	1.22	0.225
One month	1 month	0.7273 ± 0.21864	1.22	0.225
Six months	Base^*	0.7792 ± 0.39526	–0.28	0.98
Six months	6 months	0.7796 ± 0.30953	–0.28	0.98

*Preoperative value.

SD: standard deviation.

DUS parameters

In all cases, there was a statistically significant increase of PSV and RI values one week and one month postoperatively (P < 0.0001) but returned to be near to the preoperative values at six months. As regards EDV, there was a slight but non-significant increase postoperatively (P > 0.05) which did not return to the preoperative value as shown in Table 3 and Fig. 3.

Table 3.

Preoperative PSV, EDV, and RI values compared to the values at one week, one month, and six months postoperatively.

	Mean ± SD	Paired t	P
One week
PSV
Base^*	10.9397 ± 2.06628	–13.628	<0.0001
1 week	13.9095 ± 1.75101	–13.628	<0.0001
EDV
Base^*	3.7737 ± 0.88808	–1.855	0.07
1 week	3.9189 ± 0.72114	–1.855	0.07
RI
Base^*	0.6735 ± 0.09970	–17.088	<0.0001
1 week	0.7632 ± 0.10273	–17.088	<0.0001
One month
PSV
Base^*	10.9397 ± 2.06628	–9.336	<0.0001
1 month	12.4952 ±1.74683	–9.336	<0.0001
EDV
Base^*	3.7737 ± 0.88808	–1.766	0.08
1 month	3.8438 ± 0.40679	–1.766	0.08
RI
Base^*	0.6735 ± 0.09970	–4.840	<0.0001
1 month	0.7017 ± 0.10137	–4.840	<0.0001
Six months
PSV
Base^*	10.9397 ± 2.06628	–1.700	0.094
6 months	11.1508 ± 1.56007	–1.700	0.094
EDV
Base^*	3.7737 ± 0.88808	–0.869	0.26
6 months	3.7937 ± 0.95119	–0.869	0.26
RI
Base^*	0.6735 ± 0.09970	–0.921	0.181
6 months	0.6813 ± 0.10572	–0.921	0.181

*Preoperative value.

SD: standard deviation; PSV: peak systolic velocity; EDV: end diastolic velocity; RI: resistive index.

Discussion

Although many studies have assessed the testicular vascularity after inguinal herniotomy operations using DUS, the affection of DUS parameters vary considerably among these studies. In our study, we attempted to establish the foundation of these changes on DUS parameters and to some extent resolve these discrepancies. Our study showed that a statistically significant increase of PSV and RI values one week and one month postoperatively when compared with the preoperative values, but these values returned to be near to the preoperative values six months postoperatively. This result is different from the findings by Palabiyik et al. (4) which showed a significant increase of PSV and RI one week postoperatively but returned to preoperative values one month postoperatively. The increase of these values is due to increased vascular resistance of testicular vessels due to postoperative vasoconstriction and edema that disappeared one month postoperatively. In our study, vasoconstriction and testicular edema persisted until one month or more postoperatively. This may be explained by more manipulations or lack of experience of the operators. Herniotomy operation in this study was performed by the junior staff.

In the current study, there were no significant changes in postoperative EDV values when compared to the preoperative ones. This agrees with the findings by Palabiyik et al. (4).

The results of the present study differ from Çelebi et al. (9), who compared the effects of an open approach and laparoscopic hernia repair in the pediatric age group by DUS. They found that the group which was operated by open herniotomy showed a non-significant increase of PSV and RI values in the early postoperative period (one week postoperatively), but these values returned to the preoperative values in the late postoperative period (six months postoperatively). The group that was operated by the laparoscopic technique showed no changes in these values between the early and late postoperative period. Schier et al. (10) in 2008 evaluated testicular vascularity in children after laparoscopic herniotomy. They included 65 boys with unilateral or bilateral inguinal hernia in their study. They measured testicular perfusion before and after anaesthesia, before and after surgery, and six weeks later. They reported that laparoscopic herniotomy does not affect testicular perfusion.

In the present study, the comparison was done between preoperative and postoperative testicular volume values at one week, one month, and six months postoperatively and showed a statistically non-significant change of testicular volume. These results are similar to the results of Palabiyik et al. (4), which showed that there was a non-significant change of testicular volume one week and one month postoperatively when compared with preoperative values. However, these results differ from those by McGregor et al. (11), which reported a 2% testicular atrophy rate with routine herniorrhaphy. Fortunately, our study reported no cases of testicular atrophy.

The recurrence in the present study was two cases (3.3%) with the period of follow-up (six months). Kalantari et al. (12) studied 301 boys with an operated inguinal hernia. They reported the recurrence in five cases (1.7%) after one-year follow-up. The current work detected postoperative hematoma in two cases (3.3%). This is a higher rate than reported by the study of De Lange et al. (13) that found postoperative hematoma in 1.6% only. This can be explained by the low experience of the operators in our study. Our study reported no cases of wound infection. This is contrary to Ho et al. (14), who reported wound infection in 0.8% of cases. These results may be due to better methods of sterilization in the present study.

In our study, all DUS examinations were difficult and required a long time and patience. We used a high-frequency 10-MHz linear array probe (Voluson E6 B12 system). The special resolution of this probe is 0.08 mm. Hence, the exact size of intratesticular arteries in testis with volume < 1 mL was challenging. Subsequently, color and pulsed Doppler examinations were optimized at very low-flow velocities to demonstrate blood flow in the testes. Dudea et al. (15) reported that demonstration of intratesticular arteries is inconsistent until eight years of age at power Doppler sonography and until 12 years of age at color Doppler, even with 7–13 MHz probe. However, a recent study performed by Schneble et al. (16) with linear scanners (9–14 MHz) showed that color Doppler and spectral Doppler of testicular arteries could be regularly performed, even in small testes of < 1 mL. They also find that the RI of the intratesticular arteries is 0.54, irrespective of age and testicular volume.

The current study has several limitations. A possible bias is that all scans were performed and assessed by the same examiner which could affect the examiner blindness to the study and limited inter-observer agreement. However, the interval period between each examination may diminish the memory bias of examiner and avoid inter-observer variability. Another bias of this study is that all herniotomy operations were performed by less experienced operators; this might potentially affect the results of the study. Therefore, further research into how the results will be affected when highly experienced operators perform all operation is needed. A further weakness of this study is the exclusion of all patients with a complicated hernia. However, we did not include those patients because the complicated hernia could affect the preoperative Doppler measurements which were considered the reference standard for further measurements. A fourth limitation of this study is the lack of a control group. Even though we attempted to provide matched controls, it was very difficult to control for the many other potentially confounding variables at this short period. Moreover, we used testis in the same child before the operation as a reference standard which strengthens the result of the study. Finally, the duration of the study is too short. Therefore, larger longitudinal studies with long-term follow-up information would be helpful to determine if there is any long-term effect on testicular size and vascularity. Despite these limitations, the study findings highlight the valuable role of DUS in evaluation of testicular vascularity after inguinal herniotomy procedure in children.

In conclusion, this study shows that the affection of testicular vascularity postoperatively is transient and returns to be near to the preoperative values in the late postoperative period (six months postoperatively). Additionally, the study showed no significant change in testicular volume postoperatively.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

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