EAU 2019: Pilot Results from the Laparoscopic Entry Technique in Renal Surgery: A Randomized Controlled Trial Comparing Open versus Closed Techniques

Barcelona, Spain (UroToday.com) It is rare to see a surgical clinical trial, but these studies are important to continue to advance the field forward – and to question techniques that have been used indefinitely based on experience but without much evidence.

In this pilot study, the authors from a single institution in Ireland assess two commonly used techniques in accessing the peritoneal cavity during minimally invasive laparoscopic or robotic surgery – the Hassan technique (entails cutting down directly into the space) vs. Veress access (blind placement of a small needle-sized trocar and insufflation). Surgical specialties commonly using laparoscopic techniques, like gynecology and general surgery, have extensively compared the various available techniques of port insertion – but meta-analyses in laparoscopic surgery in these specialties have not been able to support one technique over the other due to insufficient evidence. However, the authors argue that results from other surgical specialties cannot simply be extrapolated to laparoscopic renal surgery due to the difference in entry site and patient position with renal surgery – though this may be a soft claim, but worth exploring. The aim of this trial was to compare Hasson and Veress techniques of laparoscopic port site entry in renal surgery specifically.

This was structured as a prospective double-blinded randomized controlled trial and was designed for patients undergoing laparoscopic renal surgery (partial and radical nephrectomy). They limited patients to those who had a BMI <40 kg/m2 and no previous laparotomy. The surgeon (and surgical team) and the patient were not aware of the type of technique prior to the procedure.

Two operating surgeons were involved at this single institution and recruitment began from October 2017. They collected data on patient demographics, type of surgery, number of attempts at entry, time to entry, major and minor complications at entry (summarized in the table below).

Table 1: Major and minor complications at entry
UroToday EAU2019 Laparoscopic Entry Technique in Renal Surgery

This trial was powered to 80% and the α-error level was fixed at 0.05, groups were assumed to be of equal size. A total of 250 patients (125 in each cohort) were required for a non-inferiority trial – with Hassan technique being considered the standard, as it was a direct visualization technique.

To date, 54 patients have been recruited in the trial – however, the trial is ongoing, and the authors invite high volume centers to participate to increase recruitment.

Of these 54 patients, 26 underwent the Veress technique and 28 underwent the Hassan technique. The two patient cohorts were demographically similar with respect to age, gender, BMI and operating surgeon.

They do note that one surgeon required a learning curve with the Veress, but both were well versed with Hassan.

These preliminary results showed no statistically significant difference between the two techniques with respect to minor complications or major complications at insertion. There was no difference in the median attempts required to gain entry with the two techniques. The median time to entry in the abdomen was faster with the Veress technique compared to Hasson, though the difference was not significant statistically.

This initial pilot shows non-inferiority of the Veress technique compared to the Hasson method of laparoscopic port site insertion in renal surgery. If anything, the Veress required less time (240 seconds vs. 300 seconds, p = 0.02) for entry, but had 4 cases that required >2 attempts for entry compared to 0 for the Hassan technique. No major complications and comparable minor complication rates noted.

More importantly, due to slow recruitment, the authors are recruiting high volume MIS centers to take part in this trial to achieve time-efficient recruitment. They require ~125 patients in each (250 patients total) for statistical purposes to demonstrate a significant difference, if one exists.

Presented by: Arun Thomas MCh., FRCS (Urol), Consultant Urological Surgeon, Tallaght University Hospital, Department of Urology, Dublin, Ireland

Written by: Thenappan Chandrasekar, MD (Clinical Instructor, Thomas Jefferson University) (twitter: @tchandra_uromd, @TjuUrology) at the 34th European Association of Urology (EAU 2019) #EAU19 conference in Barcelona, Spain, March 15-19, 2019.