Open indirect inguinal hernia repair: a feasibility study on simple purse-string suture (SPSS) application at deep ring

Introduction

Inguinal hernia repair is one of the most frequently performed surgical procedures in general surgery.^1,2 It is estimated that 20 million inguinal hernia repairs are performed globally every year.^1,3 This consumes an important part of health care resources and is therefore an economic burden. Today, inguinal hernias can be treated with very low complication rates. Open repair such as Lichtenstein repair can be performed with local anaesthesia in a safe and economic way.^3–5 Bassini first recommended excision and high ligation of the indirect hernia sac for adult inguinal hernia surgery in 1887.^3,6–8 Over time, studies have examined the optimal method for managing an indirect hernia sac.⁹ The standard repair involves hernia sac ligation characterised by the isolation, transfixation and excision of the hernial sac followed by posterior wall repair.¹⁰ The three main principles of hernia repair include high sac ligation, tensionless and sterile technique¹¹ and desired attributes are low incidence of pain and recurrence complications. It should be easy to learn, have fast recovery, reproducible results and be cost effective.¹²

Studies have shown sac ligation to be associated with postoperative hernia repair pain.^8,11 The question is whether we really need to ligate the sac. There is evidence that ligating the sac does not show any benefit over sac non-ligation when we consider the incidence of complications postoperatively.⁸ How would applying purse-string at deep ring instead of ligating the sac impact the postoperative outcomes? Little has been published on purse-string suture application in inguinal hernia repair.

In the present study, our aim was to describe the outcomes of simple purse-string suture (SPSS) application at deep ring and to determine if SPSS at deep ring could be used as an alternative to standard sac ligation. The outcome measures of interest included: length of operating time, degree of postoperative pain, postoperative scrotal swelling and haematoma, rate of wound infections, length of hospital stay, cosmetic appearance and hydrocele development.

Materials and methods

Intra-operative

SPSS of deep ring was carried out in the following manner: after exposing the sac, it was opened up (Fig. 1a). The preperitoneal fascia was identified and brought up. Four artery forceps held the peritoneum at equal distances around the ring, at the level of the preperitoneal fascia, exposing the deep ring. An SPSS was then placed around the internal ring, taking only the peritoneum and leaving the distal sac (Fig. 1b, c). Choice of stitch was vicryl 1. After that, posterior wall repair was carried out. A surgeon in the unit did either Shouldice, Bassini, Prolene or Liechtenstein darning. His choice of posterior wall repair technique was made randomly at the time of operation.

Fig. 1.

(a) Deep ring (DR) identified and exposed. (b) Simple purse-string suture (SPSS) deep ring. (c) Deep ring after SPSS application.

Results

A total of 126 patients were recruited for the study. Of these, 12 patients were excluded as follows: 7 had underlying comorbidities that led to anaesthetic cancellations and surgery being postponed, while 3 had the surgery performed but the surgeon failed to fill out the research information form during the surgery and 2 had their surgeries cancelled as they did not have money for the operation fees. Additionally, 10 patients were lost to follow-up during the initial 12-week observation period, and the subsequent observation period of 24 months. We therefore present the analysis of 104 patients who completed the assessments.

Table 1 summarises the demographic characteristics, and some outcomes of interest. The mean age of the participants was 53 years and overall mean BMI was within the normal range. Mean length of hospital stay (LOHS) was 2.1 days. The overall mean operation time was 32 min. Shouldice had the longest mean operation time while prolene darning had the shortest.

Tables 2 and 3 focus on the outcomes of interest and their distribution. Most diagnoses were right inguinal hernias. When asked, most of the patients (93%) reported a low pain scale score of 2 after the first 24 h. Out of the total participants, 65 (62.5%) had right inguinal hernia. 97 (93%) participants had a strenuous lifestyle and 87 (84%) were smokers. 52 (50%) participants had complete hernias.

The most common posterior wall repair technique was Liechtenstein with 47 (45%) participants. 79 (76%) participants were given paracetamol for pain relief 24 h after operation and 101 (97%) participants were mobilising independently in the first 24 h. Three patients had minor wound infection at 1-week review and were treated with antibiotics. The cosmetic appearance at the operation site was good for all participants. None of the participants developed hydrocele.

Discussion

Operation duration for indirect inguinal hernia repair depends on many factors. An experienced surgeon may take less operation time to do the repair compared to an inexperienced surgeon. In the present study we were interested in assessing the feasibility of SPSS application at the deep ring in open inguinal hernia repair. This was a single arm non-comparative study hence we provide preliminary evidence of the efficacy of this surgical procedure. Our overall operation duration of 32 min was a good outcome given that studies elsewhere found that open repair technique operation duration was on average about 46 min.¹⁴ The findings in our study could be useful in situations where repair needs to be done under local anaesthesia for those with comorbidities and who are unfit for regional or general anaesthesia. Short operation duration is also important for repair under local anaesthesia when repair is done as a day case. Most hospitals in PNG do not have anaesthetists. In many provincial and district hospitals, anaesthesia is administered by either an Anaesthetic Scientific Officer (ASO) or by the operating surgeon. Lesser operating time in SPSS is therefore important for quick recovery, avoiding the need and risk of extending anaesthesia.

We considered other factors that may have influenced our operation durations. These factors included types of hernia, repair technique and the surgeon who did the repair. However, these factors did not yield statistically significant differences and we are therefore not able to tell whether they can influence the operation duration. This was an important and therefore encouraging finding given that most of our inguinal hernia repairs are conducted by registrars. The implication is that registrars performing hernia repair with SPSS application should be able to complete repairs in a shorter operation duration.

Postoperative pain is a major post hernia repair complaint.¹⁵ Post repair pain contributes to slow recovery and to the ability of patient to mobilise after repair. A meta-analysis on randomised controlled trials which assessed sac ligation in inguinal hernia repair suggested that hernia sac ligation was associated with higher postoperative pain and suggested that severity of pain from sac ligation may last up to 5.6 days on average.¹¹ Our present study on SPSS had a pain scale of 2 after 24 h for 93% (n = 97) of the participants. This was an important finding given its implication that with less postoperative pain, SPSS repair could be done as day cases. In the present study, the mean length of hospital stay was 2.1 days. We purposely kept most of these patients longer in the hospital for two reasons. First, these patients came from remote villages making it difficult for us to contact them if we let them go. We decided to keep them longer to ensure they were well before we let them go. Secondly, if we let them go early, they wouldn’t be able to look after their operation sites well in their remote villages. The reduced postoperative pain findings suggest that we can do repair as day cases and patients could benefit from a reduced LOHS-related cost of hospitalisation. Patients were able to mobilise freely and were discharged home the next day.

There were factors like posterior wall repair technique and type of anaesthesia that we thought would influence the post repair pain, but they did not yield statistically significant differences in the final analysis. This finding implies that SPSS technique may have an effect in reduced postoperative pain. During the post hernia repair review period, none of the participants developed scrotal swelling and/or haematoma. In addition, there was no hydrocele development in the 12-week postoperative or the 24-month total observation period. This was probably due to minimal tissue dissection in SPSS. The cosmetic appearance was also good. This highlights the needless effort to ligate the sac.

Recent meta-analysis from a Cochrane review⁴ and from another review¹⁶ suggests that prophylactic antibiotics do not reduce the rate of surgical site infection. This suggests that administration of antibiotic prophylaxis for elective inguinal hernia repair cannot be universally recommended. Wound infection rates remain at 1–7% even with prophylactic antibiotics.^4,17 In the present study, three patients (2.9%) developed mild wound infection in the first week but recovered in the second week. This suggests that SPSS is not associated with a high chance of wound infection. Although our mean length of hospital stay was 2.1 days, short operation duration and less post repair pain observed in SPSS suggests that repair can be done as a day case. We believe a larger study would be able to establish if the patterns observed remain as informative. A methodological limitation of this study is the absence of a control group on SPSS and sac ligation that would give a clearer description on the outcomes based on direct comparison. In addition, since SPSS is not a major operation, we did not consider mean blood loss assessment. We did not consider this would alter the outcome of the study, as one would expect less blood loss because of less tissue mobilisation as in standard sac ligation. In addition, it is difficult to measure blood in our context. Usually, very small blood loss is experienced, ~10–15 mL.

In conclusion, the outcomes of this study show that SPSS application could have an important role in open hernia repair, particularly affecting the operation time and the postoperative pain. There is less chance of post repair scrotal swelling and haematoma, and cosmetic appearance is good. SPSS is a possible alternative technique to standard sac ligation in open indirect inguinal hernia repair as it involves minimal tissue dissection and has good outcomes. SPSS is a simple and safe technique that is applicable in low-resourced settings like Papua New Guinea. It will therefore be worth exploring in a future comparative study of sac ligation versus SPSS application.