A Single-Blinded,Randomized Comparison of Laparoscopic Versus Open Bilateral Hernia Repair in Boys

Introduction

Over the past decade, laparoscopic techniques have been applied widely in the management of common pediatric diseases. ¹ After a review of 131 clinical reports published over the past 10 years that described the most common pediatric surgical diseases managed laparoscopically, Rangel et al. ² concluded that current evidence is insufficient to justify the widespread adoption of the laparoscopic approach as the accepted standard of care. Therefore, it is important to critically evaluate the efficiency and potential risks of these new techniques before they become the treatment modality of choice.

Bilateral inguinal hernias can be repaired through traditional open surgery using two incisions or in a single laparoscopic procedure. Although some studies exist in younger ages,^3–6 there are limited numbers of studies on older boys who are able to describe their pain and wound appearance after this procedure. Because postoperative pain is a highly unpleasant experience for children and greatly affects their recovery from surgery, we therefore designed this study in order to compare repair of an inguinal hernia (IH) in laparoscopic repair (LR) groups and open repair (OR) groups for bilateral cases in terms of pain and use of analgesia. The secondary goals of this study were to investigate the feasibility of performing bilateral LR and OR and to compare operative time, patient satisfaction, wound appearance, and functional limitation.

Subjects and Methods

After the study was approved by the ethics committee of our institution, informed consent for surgery was obtained after the intent of the study was explained to the parents. From May 2011 to May 2013, we randomly assigned to the different repair groups 62 consecutive pediatric patients with bilateral IH at our institution.

Patients who agree to participate in the study were informed about postoperative hospitalization. Therefore, patients operated on an outpatient basis were not included in the study.

Pain intensity was estimated using a visual analog scale (VAS) by the patient, which is a widely accepted method ⁷ (Fig. 1). Because the patients' responses were considered an important VAS factor, only patients older than 6 years of age were included in our study. Diagnosis of IH was confirmed during a preoperative examination performed by an attending physician.

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FIG. 1.

Visual analog pain chart.

In addition, only boys were included, as the types of surgery and operative times differ technically in girls with IH. Children with inflammatory changes, testicular abnormalities, hydroceles, recurrent hernia, or previous abdominal surgery were also excluded.

Patients had been visited before the surgery and given an explanation on how to use patient-controlled analgesia (PCA) for postoperative pain relief. Before the operation, the VAS pain chart had been also explained to all the patients, and they were familiarized with it. The patients were randomly divided into two groups, with the randomization performed by the operating surgeon using the closed-envelope method. Group 1 included patients who underwent OR, and Group 2 included patients who underwent LR. After the operation each child had a similar wound dressing: three for the ports and two for the inguinal incisions. Children, parents, and nurses were blinded with respect to whether the patient was operated on via the laparoscopic or open technique.

During the study period only one considerably experienced surgeon in laparoscopic surgery performed both the open and laparoscopic hernia repairs. PCA administration was performed by an experienced anesthesiologist.

In both groups, general anesthesia was induced with an intravenous injection of 5 mg/kg thiopental, 0.5 mg/kg rocuronium, and 1 μg/kg fentanyl. The airway was maintained by endotracheal intubation in the LR group and a laryngeal mask in the OR group, with 2% sevoflurane and air with 50% oxygen. Operative time started at the beginning of the first incision and ended with the last suture placement.

After the transverse inguinal incision, the standard high-ligation technique was performed on the patients in Group 1. To allow adequate high ligation, the hernia sac was dissected from the cord structures and the areolar tissues at the preperitoneal pad of fat at the neck of the sac and closed by using absorbable transfixion sutures at the neck of the sac^8,9; the same procedure was then performed on the contralateral side. In Group 2, the patient was placed in the Trendelenburg position, and a 5-mm umbilical port for the telescope and 3-mm working ports were inserted. Pneumoperitoneum with 8–10 mm Hg pressure was established with carbon dioxide, and the internal opening of the hernia sac was evaluated. Any contents of the hernia, such as omentum or bowel loop, were carefully dissected from the hernia sac. The periorificial peritoneum was incised circumferentially at the level of the internal ring. Closure of the hernial defect was performed by closing the periorificial peritoneum with a purse-string suture at the level of the internal ring with a 3/0 nonabsorbable suture.^1,10 A complete ring of peritoneum without the presence of any visible significant portion of entrance to the inguinal canal was considered complete closure of the internal ring. Both hernia defects were closed with this same technique from the same port sides. In both groups, 0.5% plain bupivacaine (0.1 mL/kg) was infiltrated to each wound site without any nerve block at the end of the operation.

All of the patients were observed postoperatively in the recovery room and later in the ward by specially trained nurses. The patients were asked to express their pain on a VAS chart, and their postoperative pain scores were recorded at 1, 2, 4, 12, and 24 hours postoperatively (Fig. 1).

PCA was achieved with administered boluses of morphine (10 μg/kg) with a lockout interval of 10 minutes; the maximum dosage was 4 mg in 4 hours and 10 mg in 24 hours. The pumps recorded the number of boluses requested and the number delivered. The patients were allowed to self-administer their analgesic requirements. The total analgesic doses requested and delivered were assessed at 24 hours postoperatively. No other analgesic treatment was permitted during the study. All adverse events were recorded for each child.

After discharge, the patients' parents were instructed to give ibuprofen 20 mg/kg twice daily as needed.

The parents were asked to note the time their children recovered enough to resume full activity and to report it on Day 7 after surgery. Parents were specifically instructed to leave the dressing on for at least 2 days. The grading of recovery was based on the time to return to normal daily activities, such as eating, sleeping, and going to the toilet.

One of the secondary goals was to compare the two groups after discharge in terms of the wound appearance scores given by the parents. To do so, the patients were asked to attend the outpatient department for review at the third month postoperatively, and the parents were asked their opinion about the surgery and subsequent cosmesis. Scores of 100, 90, 80, and 70 were designated as excellent, very good, good, and fair, respectively. ¹¹

Statistical analysis was performed using commercially available software (Statistical Package NCSS, 2007; NCSS, LLC, Kaysville, UT). Descriptive statistical analysis included the calculation of means, medians, and standard deviations of the data obtained. The Kruskal–Wallis test was used for the statistical analysis of the variable between groups, and Dunn's test was used for the subgroups. P values <.05 were considered statistically significant in all analyses, and the confidence interval was accepted as 95%.

Results

Between May 2011 and May 2013, we enrolled 62 consecutive pediatric bilateral IH patients in the study. The first group included 32 patients with a mean age of 7.83±1.58 years (range, 6–14 years) who underwent OR, and the second group included 30 patients with a mean age of 8.24±2.60 years (range, 6–13 years) who underwent LR. Both groups were statistically similar in age (P=.32).

Although the operative time for LR was slightly shorter, there was no statistically significant difference in operative time to repair the bilateral hernias between the two groups. The time for LR was 32.67±3.24 minutes, and the time for OR was 38.56±3 minutes (P=.067).

There were no traumas to the adjacent anatomical structures and no testicular atrophies, hematomas, seromas, or bruising. In addition, no infection developed at the wound site in either of the groups. No recurrence during follow-up (3 months–2 years) was observed. Three patients in the laparoscopic group had a hydrocele that resolved spontaneously during follow-up.

One patient in the OR group and 2 patients in the LR group who complained of bilateral inguinal swelling were excluded from the study. The first patient in Group 1 underwent a bilateral open exploration, but no hernia sac was found. In the 2 other patients in Group 2, the operation was terminated with diagnostic laparoscopy because of a closed internal ring opening. The remaining 59 patients continued the study. Direct IHs or femoral hernias were not encountered in either group.

Although the pain as indicated on the VAS scale decreased in both groups over time, the OR group had higher pain scores than the LR group at all times postoperatively (Fig. 2). However, the only significant difference was at 1 hour postoperatively, recorded as 6.78±3.2 versus 3.88±2.39, respectively (P=.036) (Table 1). The OR patients requested more analgesic dosages than the LR patients (12.50 versus 8.78 dosages, respectively), and they also delivered more analgesic dosages per 24 hours (11.88±5.56 versus 8.35±6.63 dosages, respectively) (P=.321) (Table 2). However, there was no statistically significant difference.

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FIG. 2.

Visual analog pain scores.

No patient in the OR group experienced shoulder pain, whereas three children in the LR group complained of it. Shoulder pain lasted for a mean of 6 hours (range, 3–9 hours).

Both groups of patients were able to resume eating soon after the operations. In the OR group, 1 patient had postoperative vomiting, which was cured without medical help. Both groups of patients were discharged within 24 hours after the operation, and the children did not experience any problems at home. After discharge, the requirement for ibuprofen was 1.28±1.2 doses in the OR group and 0.78±0.8 in the LR group (P=.428).

The mean time to restore normal daily activities after surgery was 2.4 days (range, 1–4 days) in the LR group and 1.8 days (range, 1–3 days) in the OR group (P=.32).

The parents were very satisfied with the wound cosmesis in the bilateral LR group, and most of them graded the wound cosmesis as excellent. The wound score for this group was 89±4.23, which was much higher than the score for the OR group (78±6.7); the difference was statistically significant (P<.05).

Discussion

OR of an IH, which is the most common operation performed by pediatric surgeons, has been accepted as the method of choice since it was first described more than 50 years ago. However, over the past decade, laparoscopic techniques have been applied widely in the management of common pediatric diseases.

Collective trials comparing laparoscopic and open techniques for IH repair in adults have found that patients who underwent LR resumed their usual activities earlier and suffered less persistent pain and numbness than patients who underwent OR. ¹² Although there have been many studies on adult patients, the number of studies of pediatric patients is very limited.^3,6 It seems logical that if such benefits occur for patients undergoing primary IH repair, there may be even greater benefit to patients undergoing bilateral IH repair because an open approach requires two incisions, whereas bilateral repair can be accomplished with only a single laparoscopic procedure. This is the first study to date of pediatric hernia repair that focuses on bilateral cases in older boys. This single-center trial has the advantages of clearly defined procedures and uniform postoperative care and analgesia.

The three-port technique of LR enables the repair of bilateral hernias; insertion of the three ports takes about 5 minutes. Thus far, in cases of unilateral hernia, LRs had longer operative times than ORs. ³ However, we observed no difference in operative times between LR and OR in bilateral cases; this could be because the operation can be completed without adding extra ports.

Several studies have indicated that nurses underestimate the amount of pain experienced by children, and they do not administer prescribed analgesics in a way that adequately controls pain. ¹³ Pain is a subjective experience; only the patient can truly sense the intensity of pain. As such, in this study, the child's assessment was accepted as a valid index of the amount of pain suffered. ¹⁴ The VAS was chosen because it has proved to be a reliable and valid tool for measuring clinical pain, and it has been shown to be sensitive to variations in pain intensity. ¹⁵ To conduct a more objective study, we chose patients older than 6 years of age and monitored analgesic requirement of patients for 24 hours postoperatively prior to discharge. Although the postoperative pain profiles of the two groups were similar, the pain scale was lower in the LR group at all postoperative times than in the OR group; however, the only significant difference occurred during the first postoperative hour. In the study of Koivusalo et al., ⁶ laparoscopic hernia repair was associated with increased postoperative pain in unilateral cases of pediatric hernia. This could be because in their study they used 5-mm ports. We used 3-mm instead of 5-mm ports in order to reduce postoperative pain and improve cosmesis. Also, although bilateral cases involve two open incisions, in bilateral LR only there is an incision, similar to the procedure for unilateral LR. Our data also showed that the percentage of pain relief increased over time. Similarly, hourly drug usage also decreased up to 24 hours in both groups.

PCA-based analgesic consumption is not a precise method of determining the degree of analgesia, but it is the only available method of objectively determining drug requirements. ¹⁵ PCA has been documented as decreasing children's anxiety. ¹⁶ Children as young as 6 or 7 years of age can learn to use PCA. ¹⁷ Chan et al. ³ suggested that postoperative requirements for pain medication are reduced after LR. In our study, although there was no statistically significant difference, the bilateral LR group required fewer doses of analgesic, indicating that this type of repair was less painful. We also found that PCA is an effective technique for providing analgesia after surgery.

In bilateral open cases, the surgeon has to explore both inguinal grooves and, in so doing, theoretically doubles the risk of damaging the surrounding inguinal structures. ¹⁸ LR has the advantage of avoiding the cutaneous fibers of the ilioinguinal and genital branches of the genitofemoral nerve (GFN), thus protecting sensation in the scrotum and the cremasteric reflex. ¹⁹ GFN motor response was significantly affected after OR, ¹⁸ whereas GFN motor functions are better preserved in LR. ¹⁹ LR also involves less interference with the vessels and lymphatics, which are rather scarce or divert from the inguinal region. ²⁰ Palabiyik et al. ²¹ reported that open hernia repair affects the vascularization of testes in early stages. A recent study found no vascular impairment in the early and late stages following LR. ²⁰ The higher pain scores and analgesic requirement for OR compared with LR at 1 hour postoperatively might be due to possible trauma to these inguinal structures.

In a randomized study Chan et al. ³ found that the mean time to resume full activities was not statistically different between LR and OR. The results of our study support this conclusion. The nearly identical times required for the children to resume their normal daily activities after LR and OR indicated that recovery after these procedures is very similar.

According to the current literature, LR is superior to open surgery in terms of cosmetic appearance.^3,22 Chan et al. ³ reported that the scores given by parents for wound appearance were slightly but significantly higher after LR. The results of our study support this conclusion. In bilateral OR, there are two 2–3-cm transverse incisions, whereas in LR, there are only two 3-mm and umbilical incisions, which are almost invisible after 3 months postoperatively. Parents are very satisfied with this aspect. One may speculate that in open surgery inguinal incisions would be covered by the child's underwear and that the laparoscopic incisions, although small, would be visible with the underwear in place. But, we see that incisions in many children, especially those older than 6 years of age, tend to heal with scar formation more than in smaller children. This could be the reason why we found better cosmesis in the laparoscopic group.

One patient in the open surgery group went on to a negative finding on surgical exploration, but 2 patients in the LR group had only laparoscopic intervention for diagnosis. Therefore, unnecessary exploration was avoided. The laparoscopic approach provides the advantage of confirming or ruling out the diagnosis in the rarer cases where the hernias are suspected but not easily detected preoperatively, without the need for an exploration.

One may speculate on the use of PCA in the present study because nearly all centers (including our own clinic) routinely use acetaminophen for postoperative analgesia following hernia repairs. However, it has been reported that nurses might underestimate patients' analgesic requirements and fail to administer prescribed analgesics in a way that adequately controls pain. ⁸ We therefore concluded that monitoring patients' self-administration of morphine would provide more objective data.

In conclusion, operative time, pain relief, analgesic requirement, recovery time, and surgical outcomes were similar in both techniques. Although we state that the choice of operative procedure is not of major importance, we believe that in elective repairs of bilateral IHs, the patient should also be given the option of laparoscopic hernia repair with partial excision and the purse-string technique because of its cosmetic superiority over OR.