Single port laparoscopic repair of paediatric inguinal hernias: Our experience at a secondary care centre.

BACKGROUND: Congenital inguinal hernias are a common paediatric surgical problem and herniotomy through a groin incision is the gold standard. Over the last 2 decades minimally invasive surgery (MIS) has challenged this conventional surgery. Over a period, MIS techniques have evolved to making it more minimally invasive - from 3 to 2 and now single port technique. All studies using single port technique are from tertiary care centres. We used a modification of the technique described by Ozgediz et al. and reviewed the clinical outcome of this novel procedure and put forth our experience at a secondary level hospital.
MATERIALS AND METHODS: Prospective review of 37 hernias in 31 children (29 male and 2 female) (8 months - 13 years) performed laparoscopically by a single surgeon at a single centre between September 2007 and June 2010. Under laparoscopic guidance, the internal ring was encircled extraperitoneally using a 2-0 non-absorbable suture and knotted extraperitoneally. Data analyzed included operating time, ease of procedure, occult patent processus vaginalis (PPV), complications, and cosmesis.
RESULTS: Sixteen right (52%), 14 left (45%) and 1 bilateral hernia (3%) were repaired. Five unilateral hernias (16.66%), all left, had a contralateral PPV that was repaired (P = 0.033). Mean operative time for a unilateral and bilateral repair were 13.20 (8-25) and 20.66 min (17 -27 min) respectively. Only one of the repairs (2.7%) recurred and another had a post operative hydrocoele (2.7%). One case (2.7%) needed an additional port placement due to inability to reduce the contents of hernia completely. There were no stitch abscess/granulomas, obvious spermatic cord injuries, testicular atrophy, or nerve injuries.
CONCLUSION: Single port laparoscopic inguinal hernia repair can be safely done in the paediatric population. It permits extension of benefits of minimal access surgery to patients being managed at secondary level hospitals with limited resources. The advantage of minimal instrumentation and avoidance of intracorporeal knotting makes it a feasible technique for a secondary care centre.

INTRODUCTION

Congenital inguinal hernias are a very common paediatric surgical condition.[1] The basic defect in paediatric inguinal hernias is the failure of the processus vaginalis to close. Further, the inguinal structures are arranged in a live, dynamic active and remarkable manner and contain important and delicate structures like the vas, testicular vessels, femoral vessels and the nerves in the region.[2] The surgeon strives to correct the basic defect in as simple manner as possible taking care not to damage these structures and mechanisms. It is well understood that all that needs to be done is to close the PPV at its neck by shutting off the connection with the general peritoneal cavity.

Inguinal hernia in children is traditionally repaired through a groin incision by dissecting the hernia sac from the spermatic cord and suture ligating its base. Over the last 2 decades, MIS has challenged this gold standard surgery.[3] Advantages of MIS techniques include avoidance of access trauma, decreased operative time and ability to assess the contralateral side.[4] Over a period, MIS techniques have evolved to making it more minimally invasive –from 3 to 2 and now single port and from intracorporeal knotting to extracorporeal knotting.[5] All studies using single port technique are from tertiary care centres. We used a modification of the technique described by Ozgediz et al.[4] and reviewed the clinical outcome of this novel procedure and put forth our experience at a secondary level hospital.

MATERIALS AND METHODS

Study design

Prospective review of 37 hernias in 31 children (25 male and 1 female) performed laparoscopically by a single surgeon at a single centre between September 2007 and June 2009.

Surgical technique (online resource 1)

All cases were performed under general anaesthesia. A modification of the technique described by Ozdegiz et al.[4] was used. The patient was placed in a reverse Trendelenberg's position with the monitor stationed at the foot end of the table and to its right. A single prophylactic dose of Injection Cefuroxime was administered. Pneumoperitoneum was created by closed method using a Veress needle and pressure kept between 10-12 mm of Hg. A 5 mm, 30-degree laparoscope was introduced through an umbilical port and the internal ring (IR) was visualized to confirm the PPV. The IR on the other side was then visualized to pick up an occult PPV if any. The size of the IR was roughly estimated by the ease of which the 5 mm scope could enter it. After localizing the internal ring with a 26 G needle, a 2-mm stab incision was made using a No. 11 blade. Working from right to left, a 2-0 silk suture swaged onto a 45 mm curved needle was introduced through this stab incision [Figure 1] and the neck of the hernial sac was encircled extraperitoneally, the needle traversing the peritoneum only to skip over the vas and testicular vessels at its coalescence [Figures 2 and 3]. The needle was then brought out through the skin on the opposite side of the IR, lateral to the inferior epigastric vessels (IEV) partially, and then backed over the superior part of the ring in a plane just above the peritoneum. The needle was then brought out of the stab incision, swaged end first [Figure 4]. The needle was cut and the suture knotted, cut and the skin lifted to sink the knot in [Figure 5]. For a left-sided hernia, the encirclage was started just lateral to IEV and proceeded similarly.

Figure 1

Silk suture being introduced through the stab incision after localizing the internal ring with a 26 G needle

Figure 2

The needle is being negotiated around the neck of the sac extraperitoneally

Figure 3

The cord structures have been skipped avoiding damage to them (Arrow)

Figure 4

The needle is brought out and backed swaged end first to bring it out through the stab incision

Figure 5

The neck of the sac closed by the extraperitoneal ligation

Pneumoperitoneum was reduced and the scope and trocar withdrawn. The fascia was closed with 3-0 Monocryl suture and skin closed with the same suture using subcuticular buried suture. Small dressings were placed over the umbilical and stab incision.

Postoperatively, the patient was given oral Ibuprofen for analgesia and permitted oral fluids after 4 hours and discharged the next morning with instructions for wound care and reviewed at 1 week, 1month, 3 months and 6 months thereafter. Patients who could not be brought for review were interviewed telephonically.

Study parameters

Data analyzed included side of hernia, duration of symptoms, operating time, the ease of procedure, occult PPV, complications, both, intra- and postoperative especially recurrence rate, hydrocoele formation, suture abscess/granuloma and testicular atrophy, and cosmesis. Statistical analysis was done by chi-square test.

RESULTS

The results are tabulated as Tables 1 and 2. Thirty-seven hernias in 31 children were repaired. The age of patients varied from 8 months to 13 years (mean = 3.87 years). There were 16 right (52%), 14 left (45%) and 1 bilateral hernias (3%). Five unilateral hernias (16.66%), all left, had a contralateral PPV and were repaired (P = 0.033). The mean duration of symptoms was 7.32 months (1–36 months). Mean operative time for a unilateral and bilateral repair were 13.20 min (8–25 min) and 20.66 min (17-27 min), respectively. One procedure was for recurrence after open repair. The operated cases were followed-up between 12 and 44 months (mean = 21.16 months).

Table 1

Results

Table 2

Complications

Only one of the repairs (2.7%) recurred and another had a postoperative hydrocoele (2.7%), which resolved on its own. One repair (2.7%) needed an additional port placement due to inability to reduce the contents of hernia completely and retroperitoneal haemorrhage occurred in one repair (2.7%). There were no stitch abscess or suture granulomas. There were no obvious spermatic cord injuries, testicular atrophy, or symptoms of femoral or ilioinguinal nerve injuries.

DISCUSSION

The incidence of inguinal hernia in children is about 0.8 – 4.4% with a higher incidence (up to 30%) in premature babies.[6] The most feared complication of inguinal hernias in children is incarceration and strangulation, the risk of which is highest in the first year of life.[7] Hence a surgery is advocated at the earliest and the cornerstone of this surgery is the high ligation of the PPV. The traditional herniotomy has been a proven procedure with low recurrence but has its inherent problems that include access trauma due to dissection of the vas and vessels with risk of injury, a relatively large groin incision, technical difficulty in small babies and inability to assess the contralateral side thus requiring a separate incision/procedure to tackle the other side.[8]

With the advent of MIS, surgeons have adopted this technique to further improve/overcome these drawbacks without increasing recurrence rates.[9] It all started with the laparoscopic evaluation of the contralateral side via the open ispsilateral hernial sac.[1011] Thereafter, minimally invasive techniques were accomplished with 3 ports and intracorporeal knotting[1213] or by special devices, such as a curved Reverdin needle and Lapaherclosure[1415] with 2 ports. Recently further innovation has led to 1 trocar extraperitoneal closure of the IR with simple extracorporeal knotting.[489] The first report of such a technique was by Ozdegiz et al.[4] in 2005 wherein he used an additional receiving Tuohy needle to accomplish the encirclage. In the present technique, the same was achieved without the use of any such additional devices.

One significant advantage of laparoscopic techniques in paediatric hernias is the ability to pick up occult PPVs thus preventing metachronous hernias. The reported rates of occult PPVs in literature are 23-37%.[416] However, in our series, only 16.66% of cases had an occult PPV. This may be explained by the comparatively older children in our series as compared to the other series wherein there were neonates and preterm babies. Upto 40% of PPVs are known to close by 2 months and 60% by 2 years of age. The criteria used for repair of occult PPVs are if it is more than 2 mm or the sac is more than 1.5 cm in length.[49] A literature review showed that the processus vaginalis closes earlier on the left side than on the right side. Thus if a left-sided hernia is present, there are more chances of a PPV on the right side.[17] This assumption was confirmed in our study wherein all cases of occult PPVs were associated with left-sided hernias and this was found to be statistically significant. Another advantage is the ability to tackle synchronous hernias through a single incision only. There were a total of 6 bilateral hernias that were successfully repaired. However, in one case, irreducible omentocoele necessitated the placement of an additional port to reduce the contents before the repair could be undertaken. This was the oldest case in our series, a 13-year-old boy. In literature, inguinal hernias up to the age of 16 years have been managed by this technique successfully.[4]

One of the aims of this procedure would be reduce the operative times. In the best of the hands, the median operative times in a 3 port technique reported are around 20 min.[12] The mean operative time in our series was 13.20 min for a unilateral hernia and 20.66 min for a bilateral repair. The same in another series reported was 15 and 25 min, respectively.[18]

All other techniques of paediatric inguinal hernia repair are going to be measured against the rates of the gold standard open herniotomy. The reported recurrence rates for open herniotomy in children vary from 2-6.3%.[19-21] The same in laparoscopic 3 port techniques ranges from 0-5.3%.[12132223] The rates of recurrence for the single port techniques reported are 0-4.8%.[3418] The recurrence in our series is comparable to these figures [Table 3].

Table 3

Comparison of recurrence rates of inguinal hernia following single port laparoscopic repair with other published series

If we look at the simplicity of this procedure, it no doubt has a learning curve but in the opinion of the authors, it is a relatively short one. An indicator of the learning curve gradient will be the operating times and recurrence rates as the number of cases increase. In our series, looking at unilateral repairs, the first case took 25 min, the first 8 cases averaged 18.29, the next eight 12.75 and the last 9 cases averaged 10 min, respectively [Figures 6 and 7]. The operative times for B/L hernias are shown in Figure 8.

Figure 6

Graph depicting the operative times for unilateral repairs

Figure 7

Decreasing operative times (unilateral cases) as the number of cases increased

Figure 8

Operative time for bilateral repairs

Of the recurrence rates mentioned in literature in one series 5/13 recurrences occurred in the first 4 months and only 2 of them occurring in the last 100 cases.[4] In another series 5/7 recurrences occurred in the first 35 cases and only 2/7 in last 77 cases.[18] In our series the only recurrence was in the eighth case and the compounding problems were that it was the first left sided hernia (unfamiliarity) that was being done and had a large (2 cm) ring (technical difficulty). There were no conversions to open procedures in our series. Thus, the technique can be picked up rapidly and with a fair amount of comfort, ease and good results can be achieved.

Looking at the complications, the additional problem of any laparoscopic procedure is the need for a transperitoneal access and the attendant risk of visceral/vascular injuries. The rate of major and minor complications in a series to evaluate the risk of needle and trocar injuries in laparoscopic procedures was 0.41% and 1.58%.[27] Fortunately, in our series we had no such complications. In one case (2.7%), while negotiating the IR ring there was injury to one of the smaller veins leading to a small retroperitoneal haemorrhage, which was rapidly controlled by deflating the pneumoperitoneum and applying pressure externally through the anterior abdominal wall. Thereafter, the pneumoperitoneum was re-created and the procedure completed. Another potential complication can occur while negotiating the IR medially leading to injury to IEVs but we did not encounter any such problems. In the postoperative period, no patients had any immediate problems and were discharged the next morning. Though technically, they were fit to be sent home the same evening, this was not done due to logistical problems with the parents coming from remote, faraway places with problems of conveyance and also due to administrative reasons.

In the follow-up period, hydrocoeles are a well-known complication that can occur and the reasons for this could be either a persistent distal sac allowing for the accumulation of the fluid compounded by the small defect left behind due to ‘skipping over’ the vas and vessels, which act like a 1-way valve or taking additional tissue in the purse string suture around the peritoneum.[418] However, it has been observed that most of these hydrocoeles are self-resolving requiring a second procedure only occasionally.[4] In our series postoperative hydrocoele occurred only in one case (2.7%) and it resolved on its own.

Other reported complications of this technique are suture abscess and granulomas.[418] However, we did not encounter a single such complication. There are also concerns regarding injury to femoral and the ilio-inguinal nerve injuries and testicular atrophy secondary to injury to the testicular artery that can occur but we found no such cases.[49] Further, there were no obvious injuries to the spermatic cord. Needless to say, the cosmesis was found excellent by the parents with only one 5 mm incision at umbilicus whose scar is inconspicuous after a few months.

CONCLUSION

Single port laparoscopic inguinal hernia repair can be safely done in the paediatric population. It permits extension of benefits of minimal access surgery to patients being managed at secondary level hospitals with limited resources. In addition, it combines the advantage of being simple, reduced operative time, and better cosmesis. The advantage of minimal instrumentation and avoidance of intracorporeal knotting makes it a feasible technique for a secondary care centre.