Our Laparoscopic Surgical Technique and Experience in Treating Pediatric Inguinal Hernia Over the Past Decade.

BACKGROUND: Over the past decade, laparoscopic hernia repair was the most performed operation in our department. Equally, it compromises 15% of all pediatric operations performed. We aim, in this study, to review all the cases performed and extrapolate important information like reoccurrences, the incidence of metachronous inguinal hernia, complications amongst other information.
MATERIAL AND METHODS: All patients under the age of 18 whom underwent elective laparoscopic hernia repair between 03/01/2007 till the 18/05/2016 were included in our study. We recorded important clinical features and studied their post-operative follow up. Equally reoccurrences, the incidence of metachronous inguinal hernia, complications and other parameters were recorded and studied.
RESULTS: A total of 916 patients were operated on during the defined study period. There was a 0.17% reoccurrence rate and a 0.46% incidence of metachronous inguinal hernia. Equally a contralateral patent processus vaginalis was diagnosed and closed in 17.10%. There were no postoperative complications and we had a 0% postoperative hydrocele rate.
CONCLUSION: Laparoscopic hernia repair is safe and carries all the benefits of minimally invasive surgery. We recommend that it is offered to patients and would like to refute previously claimed reports that it carries a higher reoccurrence rate or takes a long time to perform. Our reoccurrence rate of 0.17% is actually lower than many published reoccurrence rates after open repair. Copyright:

INTRODUCTION

Inguinal hernia is a very common condition presenting among pediatric patients. Different studies have reported varying incidence rates ranging between 0.8% and 4.4% with an incarceration rate of 30% for untreated cases.[123] This incidence rate is even more for premature infants, where the rates can reach as high as 30%.[4] The historical and classical treatment for inguinal hernia is high ligation of the processus vaginalis by open repair. During the past two decades, a variety of laparoscopic techniques have been described and surgically implemented. In this study, we review our current practice of laparoscopic repair over the period from January 03, 2007 to May 18, 2016 and present our results.

MATERIALS AND METHODS

We performed a retrospective review of all the patient's records whom underwent elective laparoscopic hernia repair aging <18 years of old between January 03, 2007 and May 18, 2016. The following parameters were examined and studied: clinical features, operative findings, demographics, age, type of hernia, the duration of hospital stay, the need of conversion, recurrence, and reoperation for a contralateral metachronous hernia and complications. All patients not fitting the above-mentioned criteria were excluded from the study sample.

Surgical technique

Our surgical technique required one optical trocar of 5 mm and two operative trocars of 3 mm. A zero-degree optical telescope is inserted through an umbilical trocar which is created according to the known open method. Pneumoperitoneum is maintained between 8 and 12 mmHg. The two other operative trocars are inserted under direct visual supervision at the lateral border of the recti muscle one fingerbreadth inferior to the umbilical trocar. We initially started by general inspection of the two inguinal internal rings to confirm the presence of a contralateral patent processus vaginalis (CPPV). Then, the process vaginalis is dissected completely from the peritoneum while maintaining a good distance from the vital structures in proximity (vas deferens and spermatic vessels). In females, we always divide the conjoint tendon with bipolar diathermy. After the complete dissection of the process vaginalis, its complete mobility is further confirmed by pulling it with forceps and ensuring it is not attached to any other structures. Following the previous steps, the process vaginalis is transected and the distal part retracts distally where the proximal part is exteriorized. The procedure is completed by closing the internal inguinal ring with a 3/0 Ethibond for which the needle is introduced directly by piercing the skin above the internal inguinal area, under visual control, into the abdominal cavity. The knot is tied intracorporeally and the needle is then exteriorized under visual control with one of the operative trocars. The umbilical camera port aponeurosis is closed, whereas the two operative ports are steri-stripped.

RESULTS

In total, 916 patients were identified in the study period. Ages ranged from 7 months to 17 years with an average age of 5.1 years. Study population was divided into the known pediatric age groups yielding n = 28 in infants (age 28 days to 12 months of age), n = 159 in toddlers (age 13 months to 2 years), n = 448 in early childhood (age 2–5 years of age), n = 228 in middle childhood (age 6–11 years of age), and n = 53 in early adolescence (age 12–18 years of age). There were 650 males and 266 females and preoperatively, 527 patients were diagnosed to have a right-sided hernia, 274 patients with left-sided hernia, and 115 to have bilateral hernias. During laparoscopy we confirmed that the 115 patients whom were diagnosed with bilateral hernia, did actually have bilateral hernia. Of the 801 patients diagnosed preoperatively to be single sided, 2 had no hernias at all, 3 had a femoral hernia, 9 had a direct hernia, 137 had a CPPV, and 650 were confirmed to be single sided. In addition, other pathologies detected were 3 spermatic cord cysts, 1 ovarian cyst, 2 ectopic testicles in the opposite sides of the hernia, and 3 umbilical hernia. In total, the number of hernias repaired was 3 femoral hernias, 9 direct hernias, and 1155 indirect hernias. In our series, there was a 0% conversion rate. Of the 1155 hernias repaired only two reoccurred 0.17%. This recurrence occurred in a 3-year-old child, 8 months after his left-sided hernia was repaired. The hernia was subsequently re-repaired laparoscopically, and the symptoms did not reoccur. The other recurrence occurred for a 6-year-old boy whom was diagnosed with left-sided hernia and had a right CPPV discovered during the intervention and repaired. The boy presented 6 years later with a right inguinal hernia that was also repaired laparoscopically.

Contralateral metachronous hernia occurred in 3 children of the 650 (0.46%) diagnosed to only have a single-sided hernia. At the time of the operation, the surgeon did not report a CPPV. One occurred in a 6-year-old boy 5 years later, one in a 2-year-old boy 4 years later, and one in a 3-year-old girl, 3 years after. There were no complications during our series; however, we had a 12-year-old girl that had to undergo an explorative laparoscopy 3 years after her hernia repair for inguina-crural pain. The intervention did not find any pathology. Equally, we had a 0% post-operative hydrocele formation rate. In addition, we typically follow-up all our hernia patients 6 months postoperatively in the outpatient department, and the pediatrician or local general practitioner carries out subsequent follow-up. In Figure 1, we present a flow chart, which outlines our findings.

Figure 1

Detailed flow chart showing the number of patients in the study alongside the respective laparoscopic

DISCUSSION

Inguinal hernias are a frequent cause for intervention for pediatric surgeons, accounting for an incidence of 0.8%–4.4% and compromising >15% of pediatric operations performed.[23] This is reflected in our department where inguinal hernia operations are the most performed operation per annum. Historically, the procedure was not performed laparoscopically; however, the laparoscopic approach is on the rise with a variety of techniques being used. Initially, laparoscopy was used by some to evaluate the contralateral side for a patent processus vaginalis, whereas before that, some practiced bilateral open exploration to avoid recurrent contralateral hernia in specific groups.[5] Up to our knowledge, the first laparoscopic procedure aimed to treat a patent processus was carried out in 1994, to treat hydroceles in four boys, whereas it was first attempted to repair an inguinal hernia in the late 1990s.[67] A variety of laparoscopic surgical techniques exist including Z type suture, W type suture, flip-flap technique, subcutaneous endoscopically-assisted ligation (SEAL), laparoscopic percutaneous extraperitoneal closure, purse string suture, and other techniques where the processus vaginalis is discontinued either via transection or complete resection.[8] The different techniques vary in terms of the number of ports used, whether the suture is performed intra or extracorporeally, the type of suture used, whether the processus vaginalis is discontinued and whether the internal inguinal ring is closed or not. As a congenital inguinal hernia is not an aponeurotic defect but rather a persistence of the patency of the processus vaginalis, some surgeons advocate the resection of the process vaginalis without closing the internal inguinal ring.[9] Riquelme et al. advocated in their study the same concept; however, they had carried out a purse string suture of the internal inguinal ring if it had a diameter of more than 10 mm.[10]

Hydrocele formation can occur post open or laparoscopic hernia repair with a reported occurrence rate of 1.5% post laparoscopic and 8.2% post open repair (P < 0.001).[11]

In regard to laparoscopic hernia repair, Tsai reported that transient hydroceles are not uncommon in techniques where the process vaginalis is not transected.[12] Tsai proposed three potential different mechanisms behind hydrocele development being incomplete ligation of the IIR, a persistent communication or a failure of a stitch of the internal inguinal ring.[12] Hydrocele formation following laparoscopic hernia repair with and without process vaginalis discontinuation, through transecting the proximal part, was studied by Abd-Alrazek et al. who found hydrocele formation to occur postoperatively in 22.1% in those whom did not have the sac transected and only 8.75% in those with sac transection.[13] This finding was statistically significant, but the study also reported that all the hydroceles in the two groups resolved spontaneously.[13] In this study, we systematically transect the processus vaginalis and close the internal inguinal ring which, in turn, provided us with a 0% of postoperative hydrocele. Table 1 demonstrates a variety of techniques with some of their characteristics.

Table 1

Demonstrating a variety of studies, showing the different technical aspects alongside the rate of reoccurrence

Year of study	Number of patients	Technique	Process vaginalis resection	Process vaginalis transection	Knot	Suture	Reoccurrence (%)	Internal inguinal ring	CPPV (%)
Lee et al., 2015[8]	98	Purse string	No	No	Intra corporeally	Prolene 3/0	0	Closed	40.7
Miyake 2016[15]	1569	Laparoscopic percutaneous extraperitonal	No	No	Extra corporeally	Nonabsorbable	0.48	Closed	44.6
Hassan, 2007[16]	15	Flip flap	No	No	Intra corporeally	4/0 poly prolene	27	Closed
S.R Lee, 2016[17]*	1214	Linear suture	No	No	Intra corporeally	3-4/0 silk	0.08	Closed	63.2
S.R Lee, 2016[17]*	1009	Purse string	No	No	Intra corporeally	3-4/0 silk	0.94	Closed
Ozgediz, 2006[18]	204	SEAL	No	No	Extra corporeally	40% primary maxon60% primary ticron	4.3	Closed	37
Shalaby, 2014[19]	874	Purse string	No	No	Extra corporeally	Nonabsorbable	1.13	Closed	20
Riquelme, 2010[11]	91	***	Yes	No	N/A	N/A	0	Only sutured via purse string if IIR >10 mm
García-Hernández, 2011[10]	285	***	Yes	No	N/A	N/A	0.53	Not sutured
Tsai, 2010[13]	161	****	No	Yes	Intra corporeally	4/0 vicryl	2	Closed	43
Abd-Alrazek, 2017[14]*	66	Intra corporeal purse string	No	No	Intra corporeally	3-0 nonabsorbable	2.6	Closed
Abd-Alrazek, 2017[14]*	66	****	No	Yes	Intra corporeally	3-0 prolene	0	Closed
Patkoski, 2006[21]	106	Purse string	No	No	Extra corporeally		2.8	Closed
Our study	916	****	No	Yes	Intra corporeally	3-0 ethibond	0.17	Closed	17.1

*Same study comparing different techniques, ***Series where the IIR was not routinely closed, however the surgeons only resected the process vaginalis, ****Series where the patent process vaginalis was transected and the IIR was ligated. SEAL: Subcutaneous endoscopically assisted ligation, N/A: Not available, CPPV: Contralateral patent process vaginalis, IIR: Internal inguinal ring

Discussions still exist in medical literature in regard to the advantage/disadvantage balance of laparoscopic hernia repair. Of the mentioned disadvantages include violating the peritoneal cavity, longer operating time, higher costs, and higher recurrences.[1415] In contrast, the advantages reported were excellent visual exposure, improved cosmesis, the need of less oral analgesia, the benefit of evaluating the contralateral side, the need of minimal dissection, technical ease, avoiding touching the cord structures, trocar placement is identical regardless of hernia side, and the potentiality of detecting other pathology.[141516]

In our institution, the operative time of both open and laparoscopic repair is comparable, a fact that is supported by a number of studies hence negating the time disadvantage associated with laparoscopic hernia repair.[151617] Moreover, wherein open surgery, time is mainly consumed in gaining access, in laparoscopic surgery time is consumed mainly in intracorporeal suturing. However, this time goes down with experience therefore, reducing the operative time.[18]

In addition, various recurrence rates were reported by various studies. In open repair reported recurrence rates range between 0.2% and 0.8%, whereas the recurrence rates in laparoscopic hernia repairs ranged from 0.6% to 3.4%.[15] In a study involving 1530 patients, all of whom were operated on laparoscopically reported a recurrence rate of 0.48%. This rate is very comparable to previously published recurrence rates of open repair.[19] The same previous study stressed the fact that surgical skill is paramount and in regard to the technique they were using, a surgeon needed to perform 30 cases to acquire the required skills.[19] Interestingly, Shalaby et al. reported a 1.13% recurrence rate in the first 703 cases done in their study, whereas the latter 450 cases had a 0% recurrence rate, an improvement that can be potentially due to the gained experience in the first 703 cases.[14] This fact can be further supported up by what Treef concluded in his study, that the more experienced the surgeon is, the fewer the recurrences observed.[20] In our series, the recurrence rate was 0.17%, which is lower than the reported recurrence rates of open hernia repairs. Our low recurrence rate can refute previous claims that laparoscopic repair carry a higher recurrence than open repair and should encourage others to embark on offering laparoscopic repairs for their patients. In our department, laparoscopic operations, in general, are encouraged, and laparoscopic trainers are available on site for surgical residents, aiming to improve the team's laparoscopic skill set. In addition, it is very important to view the results we produced today as the result of a collective learning curve where since we published our first study in 2004, the whole team with different levels of expertise embarked on taking on the laparoscopic approach. It seems that as the team collectively developed, we all became better in performing the procedure laparoscopically, which is reflected by our 0.17% recurrence rate.

In children, the cause behind an indirect inguinal hernia is a patent processus vaginalis (PPV), and the reported incidence rate of a CPPV ranges from 20% to 40%.[2] This incidence rate is reported to be around 50% in children under the age of one.[21] It is important to note that not all PPV develop into clinically detectable hernias. The processus vaginalis is a peritoneal finger-like projection which normally is obliterated between 36 and 40 weeks of gestation and if not, around 40% of PPVs are obliterated in the first few months of life with an additional 20% by the age of 2.[22] The options available for the detection of a contralateral PPV are laparoscopic, contralateral open exploration, ultrasonography, or otherwise to adhere to a wait and watch policy.[18] Laparoscopy is an excellent toot for the diagnosis of a contralateral PPV as it holds a high sensitivity and specificity of 99.4% and 99.5%, respectively.[23] An added advantage of laparoscopic surgery is the ability to detect and to simultaneously treat the contralateral side. This can prevent the possibility of a contralateral metachronous hernia developing, although some argue that the rate of contralateral PPV developing into clinical hernia is small.[15] A study compared metachronous inguinal hernia (MIH) incidence after both open and laparoscopic repair and reported that MIH occurred for 0.1% of patients that underwent laparoscopic repair where MIH occurred for 2.4% for those operated on through the classical open repair.[24] The authors concluded that CPPV repair in laparoscopy reduced the rate of subsequent of MIH however, 21 CPPV needed to be closed to prevent one MIH developing.[24] Another study also compared the incidence of MIH following open and laparoscopic hernia repair reported that following open repair, the incidence was 11.9%, whereas 0% of patient operated on laparoscopically developed MIH.[25] Moreover, in a large series of more than 1000 patients, all of which were operated on laparoscopically, a very small MIH rate of 0.22% was reported.[19] A systematic review and meta-analysis have clearly demonstrated that the laparoscopic repair of inguinal hernias has a significantly lower incidence of MIH when compared to open repair.[26] This was further supported by Alzahem whom also showed that laparoscopic hernia repair carries a significant reduction in developing an MIH.[27] A huge Taiwanese Study involving 31,000 patients, none of which had laparoscopic repair over 17 years showed that the incidence of developing MIH to be 12.3%.[28] Given the above, and coupling it with our results of 0.2% incidence rate of MIH, it demonstrates a striking advantage in the prevention of MIH by laparoscopic repair over open repair.

On the other hand, Weaver et al. were able to demonstrate that only 13% of patients whom had a PPV diagnosed, during a nonhernia associated laparoscopic procedure and a confirmed follow-up, developed symptomatic hernia which raises the question into the benefit of attempting to close PPV if found.[2] Similarly, other studies reported that less than a third of PPV do actually develop into the clinical hernia, a finding consistent with autopsy data that reported 20%–30% of PPV in asymptomatic individuals.[29]

In addition to the above, pain, cosmesis, and recovery are all factors that favor laparoscopic surgery over open repair. Chan showed that patients operated on laparoscopically suffered less pain, recovered fasters, and that wound satisfaction was greater.[25] A real danger in laparoscopic surgery is the risk of injury to the iliac vessels in the doom triangle, the gonadal vessels and both the inferior epigastric vessels and some peritoneal vessels.[3] When Patkowski initially described the percutaneous inguinal ring suture technique in 2004, he accidentally punctured the iliac vein, which fortunately required no treatment.[30] Moreover, both femoral vessel and femoral nerve injury were reported during a SEAL procedure, the first causing a retroperitoneal hematoma and the second causing ipsilateral thigh weakness.[31] Vas deferens injury and testicular atrophy are witnessed far less in laparoscopic surgery than open repair potentially owing that to the better visualization of the anatomy.[3]

Finally, laparoscopic repair holds greater advantages when compared to open repair. As shown above, the previously talked about time burden seems to have been extinct with more teams practicing more laparoscopic repairs and becoming more experienced hence shortening their operative times. Moreover, the greatest advantage is potentially the ability to diagnose and treat the opposite side, which can prevent the patient from having another operation and all of the associated stresses. In addition, the procedure can be carried out as a day case as we and others did to the majority of the cases.[1432] Improved postoperative pain relief, particularly if coupled with caudal analgesia and local infiltration, superior cosmesis, and faster recovery are all features supportive of the application of laparoscopic hernia repair. In addition, in this series, we managed to operate on babies of 7 months of age which further proves the safety and efficacy of the laparoscopic approach. Equally, it is important to note that the sole reason behind us not operating laparoscopically on younger patients is the type of anesthesia used. In our institute, patients of the age of 6 months and under are usually operated on using a spinal anesthetic hence the open approach. A few studies showed that laparoscopic hernia repair in neonates and premature infants are feasible, safe, and to be less technically demanding than the open approach.[333435]

CONCLUSION

Contrary to the general belief that the laparoscopic approach risks an elevated recurrence rate, our series reflects another reality. Our low recurrence of 0.17% should encourage pediatric surgeons to engage in offering laparoscopic hernia repair to their patients. Finally, the laparoscopic approach has other benefits like the ability to explore the contralateral side and other benefits of minimally invasive surgery.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.