Introduction

Inguinal hernia is the most frequently encountered disease requiring surgery. However, operative methods vary and it can be difficult for surgeons to choose the correct procedure. In laparoscopic hernia repair, Ger reportedly began to perform intraabdominal closure of the neck of the hernia sac under laparoscopy in 1982 [1]. Laparoscopic inguinal hernia repair began being performed safely at the beginning of the 1990s, and the procedure is now performed widely. The main advantage of laparoscopic total extraperitoneal repair (TEP) is its ability to evaluate the inguinal anatomy from the inguinal bed, allowing a coexisting hernia to be revealed, and its lower recurrence rate compared with other type of sutured repair [2, 3]. In addition, many surgeons have reported that TEP results in less postoperative pain and a shorter convalescence and postoperative hospital stay than open procedures [4–6].

Some reports have indicated a high incidence of bilateral inguinal defect being found on laparoscopic evaluation during hernia repair [7–9]. Before the introduction of laparoscopic procedures, it was reported that up to 30% of patients could develop a hernia on the contralateral side after unilateral open repair [10]. However, the incidence of contralateral inguinal hernia after TEP for unilateral inguinal hernia has not been well determined. Therefore, we carried out a retrospective study to reveal the incidence of contralateral inguinal hernia in patients who have undergone TEP for unilateral inguinal hernia.

Patients and methods

We retrospectively reviewed the result of 192 TEPs for inguinal hernia, excluding femoral hernia, in 187 patients in Beppu Medical Center from April 2003 to May 2009. Thirty patients who had clinically detectable bilateral inguinal hernia were excluded. A total of 157 patients were analyzed. Eight patients had undergone past surgery for ipsilateral hernia and two patients had undergone TEP for incarcerated inguinal hernia. The postoperative follow up was a screening at 1 month after primary TEP, with guidance to visit our hospital immediately if contralateral and ipsilateral recurrences developed.

Surgical procedure

All patients were operated on under general anesthesia. A paraumbilical incision was made and the ipsilateral anterior rectus sheath was opened. The extraperitoneal space was created using a blunt balloon tip cannula. Dissection of the extraperitoneal space was performed on only the symptomatic side, and we did not dissect and examine the asymptomatic side during the operation. Carbon dioxide insufflation was used to maintain a pressure of 10 mmHg. We used the lateral port for TEP, and the port side was made opposite the site of the hernia. We generally used a polypropylene 3D mesh and ProTack™ (Autosuture, Tyco Healthcare, Norwalk, CT) to fix the mesh.

In patients who had undergone previous TEP, the extraperitoneal space was created by the same procedure as the first TEP, and the port site was made at the lower midline or ipsilateral site of the hernia. Polypropylene 3D mesh and Protack were then used in the same way as for primary TEP.

Results

A total of 157 TEPs were performed for unilateral inguinal hernia. The mean age was 62.5 (range 20–88). There were 127 males and 30 females. Left inguinal hernia was recognized in 68 patients, and right hernia in 89 patients. The mean operation time was 73.8 min (range 25–217). A conversion to anterior repair was made for seven patients during the operation. The follow-up period was between 1 and 72 months (median 35.9 months). Postoperative contralateral inguinal hernia was found in five patients (3.2%). The mean age was 64.6 (range 29–88), and there were four male and one female. The mean period to contralateral occurrence was 12.2 (range 2–33) months after the first surgery (Fig. 1). All five patients had indirect hernia in the primary operation, and four had indirect hernia and one had direct hernia in contralateral occurrence (Table 1). The initial hernia was on the right side in three patients and on the left in two. Three of five patients had contralateral hernia in less than 6 months after primary TEP (Fig. 1).

Fig. 1
figure 1

Three patients had contralateral occurrence within 6 months after the first laparoscopic total extraperitoneal repair (TEP), while in two patients over a year passed before the contralateral occurrence

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Table 1 Details of patients with contralateral hernia after initial laparoscopic total extraperitoneal repair (TEP)
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All patients underwent TEP for contralateral hernia using the same procedure as for the primary TEP. The mean operation time was 87.2 min (range 46–120) and no patient suffered peritoneal injury during surgery. There were no postoperative complications (Table 1).

Discussion

There are a number of operative techniques for inguinal hernia, and the recurrence rate for all inguinal hernia repairs ranges from 8 to 17% [11–14]. Lichtenstein et al. [15] proposed the concept of a tension-free approach, which became established as a rapid and widespread repair method due to the avoidance of postoperative pain and decreased risk of recurrence. The incidence of recurrences after Lichtenstein’s repair was 2–5% [16, 17]. To the best of our knowledge, there has been only one report of a contralateral occurrence after this repair. Douek et al. [18] reported a contralateral occurrence rate of the Lichtenstein repair of 9%, and they have also reported a contralateral occurrence rate of laparoscopic transabdominal preperitonal repair (TAPP) of 9%.

There have been two reports of contralateral occurrence after TEP [19, 20]. Saggar et al. [19] reported that 6 of 446 unilateral repairs developed a hernia on the contralateral side. Although in four of six cases the contralateral side had been examined during the first procedure, the contralateral occurrence rate was low. Ferzli et al. [20] noted that four contralateral hernias occurred after a primary unilateral endoscopic repair in 549 patients, and that TEP repair of recurrent and contralateral inguinal hernia after primary TEP was technically feasible and safe. The 3.2% rate of developing contralateral hernia in our series was low when compared with the 7.2% incidence of metachronous contralateral inguinal hernia in children reported by Ron et al. [21].

In our series, four of five contralateral hernias were indirect, whereas all of the original five were indirect (Table 1). These results suggest the possibility that contralateral small undetectable hernia, which could not be diagnosed preoperatively, had surfaced due to preperitoneal dissection on the contralateral side or due to abdominal pressure against the primary side. Some studies have revealed a high incidence of bilateral inguinal defects in laparoscopic procedures [7, 9, 19, 22, 23]. Koehler et al. [9] reported observing occult contralateral hernia in 13% of patients examined by transabdominal diagnostic laparoscopy, and Thumbe et al. [24] reported finding incidental defects in 22% of patients during TAPP. Although untreated incidental defects would present a significant risk of developing a demonstrable hernia, TEP, unlike TAPP, requires additional dissection to make a contralateral diagnosis. Preperitoneal dissection on the contralateral side during TEP might result in the development of clinical hernia. Furthermore, TEP might increase the risk of injury to the spermatic cord. Exploration on the contralateral side during TEP might not be necessary because of our results, which indicate a low incidence of occurrence after TEP.

There have been a few reports of second TEP for recurrent and contralateral inguinal hernia after primary TEP. Ferzli et al. [20] concluded that TEP against recurrent and contralateral inguinal hernia after primary TEP is entirely feasible technically as well as entirely safe. The operating time for TEP after primary TEP was not prolonged, and the procedure did not present any serious complications in this small retrospective study. Based on these results, the preperitoneal approach would be recommended even for a patient with contralateral inguinal hernia after primary TEP.

In conclusion, we have retrospectively analyzed contralateral occurrence of unilateral inguinal hernia after TEP. The incidence of contralateral occurrence was found to be low (3.2% in our study). This result suggests that TEP is a useful procedure that should be considered for unilateral inguinal hernias.