An Expanded Retrospective Review of Trocar Site Hernias in Laparoscopic Gastric Bypass Patients

Introduction

The laparoscopic approach to abdominal surgery has long been associated with more rapid wound healing and recovery and a decrease in certain complications, including pain, abdominal wall hernias, and wound infections when compared with traditional open surgery. Laparoscopy has become the preferred approach to bariatric surgery.^1–3 This change is not without its risks, and new complications, such as trocar site hernias (TSH), have arisen. TSH carry a risk of bowel strangulation, potentially resulting in significant morbidity and mortality ³ and the need for additional surgical procedures.

The rate of clinically diagnosed TSH in laparoscopy is reported between 0.3% and 5.4%. ⁴ Almost all such hernias are found at incision sites where trocars of 10 mm diameter or greater are used or where incisional extension for specimen extraction or an open cut-down technique is used.^5–7 Smaller trocar sites (≤5 mm) have not been associated with a significant risk of herniation and are widely considered safe to close without fascial repair. Many authors recommend routine closure of fascial defects of 10 mm or greater, with varied interventions suggested.^4–6,8–10 Suture closure, mesh closure, and obliteration of the defect with a collagenous plug have been reported.^4,9,11–13 Such techniques entail time, cost, postoperative pain, and increased potential for wound infection.^4,11,12,14 In one large series, fascial closure with J-type suture needles resulted in a hernia prevalence of 0.14%, indicating that even with closure and its associated risks, avoidance of hernia formation is not guaranteed. ⁹ All prior series related to laparoscopic port site hernias are based on clinical presentation alone. We sought to examine the prevalence of asymptomatic TSH seen on postoperative computed tomography (CT) scans in a series of laparoscopic gastric bypass (LGBP) patients, where surgery was performed with unclosed port-site fascia. Our aim was to determine if the presence of such hernias might be underreported, possibly causing us to reconsider the need for fascial closure at such port sites.

Materials and Methods

After Institutional Review Board (IRB) approval, a retrospective review of all patients undergoing LGBP at the Penn State Milton S. Hershey Medical Center from 2005 to 2014 was performed. Patient demographics included mean age of 44.4 years, mean preoperative body mass index of 45.3, and female gender of 82.1%. Represented ethnic groups included Caucasian 82%, Hispanic 10%, African American 5%, and Other 3%. All procedures were performed in an identical, total linear stapled manner, as previously reported ¹⁵ by four fellowship-trained bariatric surgeons, using dilating optical trocars (Endopath Xcel; Ethicon, Cincinnati, OH). All ports were placed above the level of the umbilicus, therefore generally assumed to be well above the arcuate line. The ports were placed off the midline, and no fascial closure was performed. The standardized technique included placement of one 11-mm port, two 12-mm ports, and two 5-mm ports. No additional incisions for staplers or any other reasons were created. Any patients undergoing postoperative abdominal CT scanning for any reason at any time in the study period were included; patients who had undergone a separate laparoscopic or open operation after LGBP but before CT were excluded. We then performed a chart review of the CT reports to determine the prevalence of TSH in our study group.

Results

One thousand ninety-five patients underwent LGBP during the study period. Of these, 244 patients (22.3%) underwent at least one postoperative CT scan without an intervening surgical procedure, providing 732 port sites of 11 or 12 mm diameter to study. Only two defects (0.27%) were identified. These defects were identified in two separate patients, and the hernias were both through the abdominal musculature and fascia. One was present in an 11-mm port site and one in a 12-mm port site. Both defects were plugged with fat, were not clinically evident, were not palpable, and were asymptomatic. Of note, although 851 patients were excluded from the analysis as they did not have any postoperative CT scans, none of the 1095 total patients (3285 port sites >10 mm) had a clinically diagnosed or symptomatic TSH. We noted incidentally that 59 patients included in our study population (24%) had fat-plugged umbilical hernias on these scans, most of which had been appreciated preoperatively (Table 1).

Discussion

Laparoscopy, like all invasive interventions, is not without risk. TSH can be a significant complication, particularly if strangulation of herniated omentum or bowel occurs. Therefore, many surgeons argue for closure of trocar site fascia.^5,6,8–10

There are a number of factors that increase the risk for herniation in general. Cigarette smoking, obesity, and surgical site infection are three commonly referenced patient-associated factors, while trocar size >10 mm is reported as a common technical risk factor for herniation.^4,6,9–12 Anything increasing intra-abdominal pressure can cause theoretical increase in risk as well. At our center, we require all bariatric patients to be nonsmokers to undergo weight loss surgery (WLS). Rapid weight loss and a catabolic state may influence hernia prevalence, but this may require further study.

While numerous methods exist for fascial closure, there are costs and risks associated with all of these.^4,11,12 As the prevalence of herniation has thus far only been studied by clinical presentation, there has been doubt as to whether the true prevalence of herniation is higher due to subclinical and asymptomatic hernias being unquantified.^9,11 Our study suggests that there is no basis for that concern, at least with upper abdominal ports up to 12 mm in diameter. It is important to note that in meta-analyses, TSH were much more common when pyramidal or cutting trocars were used, and in cases of longer duration. ¹

Based on prior studies of TSH using clinical presentation alone, it has been suspected that the actual prevalence of TSH is relatively low and trocar sites may not warrant closure. ¹⁴ Our study is consistent with these suspicions, finding only a 0.27% prevalence in a study of 732 trocar sites across 244 patients who underwent LGBP. This can be compared with a prevalence of 0.14% in a study of sutured trocar site fascial closures, which the authors admitted could potentially be lower than the true prevalence, considering the use of clinical presentation alone to identify the hernias.^4,9 In those studies, “clinical presentation” included symptomatic hernias identified when patients sought treatment for pain, bowel obstruction, or other sequelae of the herniation, as well as asymptomatic hernias that were found on physical examination during postoperative follow-up. Based on our clinical presentation analysis alone, we found a 0% herniation rate over 3285 port sites in the 1095 patients who underwent LGBP at our center, despite our not having closed the fascia in any of them.

Conclusions

The rate of incisional hernias in dilating optical access trocar sites is extremely low in patients with clinically severe obesity undergoing LGBP with trocars as large as 12 mm placed above the arcuate line, as is most common in conventional WLS. Our findings should not be limited to bariatric patients alone, a population already at higher risk for herniation. Lean patients should experience even fewer TSH with unclosed port site fascia. However, we do concede that our experience is only applicable to ports off the midline and above the arcuate line. The generalizability of our assertions to lower quadrant or midline port sites is limited and is a potential area for future study. Our data also suggest that even when port site hernias are found, they are likely to be asymptomatic and are at low risk for bowel strangulation or other serious complications. Our sample size may be inadequate to make this assumption, providing another area for future study. We conclude that routine closure of the fascia of certain port sites is an unnecessary step, introducing its own risk with negligible benefit.