A Prospective Study Comparing Single and Multiport Laparoscopic Inguinal Hernia Repair

This study will compare the Laparoscopic TEP repair of inguinal/femoral hernias using the traditional three ports and the newer single port techniques.

Laparoscopic hernia repair was first introduced in 1990. The uptake rate was slow to start off with such that in 1994 only 9.7% of all inguinal hernias were performed laparoscopically However, in 2009, the figure now stands at 40% Australia-wide. (www.medicareaustralia.gov.au). Indeed, in NSW this figure stands at 48%, which means that it is the commonest operation performed for inguinal hernias in this State.

Up to 2009, the laparoscopic hernia repair involves the insertion of 3 ports: 10mm port in the infra-umbilical region for the camera via a 2 cm incision and 2 x 5mm working ports usually in the midline for the dissecting instruments via 2 x 10mm incisions. These ports are called secondary trocars which are usually sharp. Their insertion has the potential to cause bowel and vascular injuries.

The European Hernia Society guidelines (www.herniaweb.org) on the treatment of inguinal hernias have shown (conventional) endoscopic techniques to be associated with higher rates of port-site hernias and visceral injuries especially during the learning curve period.

A recent study of 37,000 gynaecological laparoscopies in the US showed a bowel injury rate of 0.16%; a third of these led to the death of the patients. 22% of all bowel injuries resulted from the insertion of secondary trocars (www.danaise.com/vascular_and_bowel_injuries_duri.htm).

Another report from a large hernia centre in the US showed that in the first 300 transabdominal preperitoneal (TAPP) repairs 2 bowel injuries (and one bladder injury) were observed. Indeed, when these investigators changed the technique to a TEP repair they also observed 2 bowel injuries (and one bladder injury) in the first 300 TEP repairs. (www.ncbi.nlm.nih.gov/pubmed/11178763)

Therefore bowel and vascular injuries during laparoscopic surgery are real but they are often under reported.

Single incision laparoscopic surgery, where all the instruments are placed in a single port, has the primary aim of preventing vascular and bowel injury through the use of completely blunt trocars. The first case of laparoscopic TEP repair was reported in 2009. Since then there have only been a handful of reports.

The principle author, Dr Hanh Tran, has been performing single incision laparoscopic hernia repair since October 2009. To date, he has performed in excess of 100 cases with excellent results in terms of success of the cure of hernias (no recurrence has been observed in any of these patients although the follow-up has only been up to 1 year), no complications including wound infection, high patient satisfaction and excellent cosmetic results.

However Dr Tran's experience is at best an audit. The highest level of scientific evidence regarding the efficacy and safety of one procedure versus another comes from a prospective randomised controlled study where two procedures are compared and the patients (with their informed consent) will undergo either procedure in a random (blind) fashion.

It is proposed that 100 patients will be enrolled into the study with 50 patients in each arm of the study ie 50 patients will undergo TEP repair using the conventional three ports and 50 with the single port technique.

The TEP inguinal hernia repair is exactly the same in both procedures except in the single port technique only one (1.5-2cm) infra-umbilical incision is required. While the first 100 cases were performed with the SILS (TM) port this required a relatively larger infraumbilical incision. The availability of the Triport (TM) allows an equally small if not smaller infraumbilical incision and this would be suited to all patients rather than those with a naturally large umbilicus. Over 180 TEP inguinal hernia repairs were performed with the Triport before the commencement of the trial to ensure that the learning curve has been truly passed. Therefore the use of the Triport allows for just one inconspicuous incision compared to three incisions for the conventional multiport inguinal hernia repair with possible improved cosmetic results.

The main disadvantage of the single port technique is the relative loss of triangulation and the principle author has shown that this can be overcome with the use of a longer and smaller laparoscope (of which Holroyd Private Hospital has bought two specifically for this purpose), different dissecting techniques and with increased experience. Therefore, if a surgeon is not experienced with this technique the operation and its success can be compromised by inadequate dissection. The author (who has performed nearly 2000 TEP repairs over the past 10 years) believes that the learning curve for single port TEP hernia repair for a highly experienced TEP surgeon is around 25-50 ie after this number the operation time will approach that of the standard three ports TEP repair. He has performed in excess of 100 Single Port Incision Laparoscopic hernia repairs over the past year. Therefore the success of the operation for patients in either arm of the study will not be compromised by lack of experience.

The follow up of these patients will be no different to those followed up under the protocol of the Sydney Hernia Clinic. This is a standard follow up and is consistent with normal clinical practice.

In summary, the goals are simple. (i) To perform laparoscopic TEP inguinal hernia repair using either the conventional three ports or single port technique; (ii) To assess the efficacy of the newer single port technique in a rigorous scientific manner; (iii) To report any unexpected problems or complications; (iv) To follow up patients treated laparoscopically to ensure that the single port technique has as good results as or better in terms of cure of hernia (absence of recurrence of the hernia) and less complications and better cosmetic results as that which is achieved when the traditional 3-ports technique is used.