A small technical change to keyhole surgery for prostate cancer can more than halve one of the most common postoperative complications, where lymphatic fluid collects in the pelvis, say German surgeons.

The findings of the trial, involving over 550 patients presented at the 2023 European Association of Urology annual Congress in Milan, showed that the post-surgical complication among the patients who underwent surgery using the new technique has reduced by 2.5 times, compared to the control group.

Making a small flap in the peritoneum, the lining of the abdomen, and attaching it to the pelvis allows the lymphatic fluid to escape from the pelvis and enter the abdomen, where it can be more easily absorbed.

Around 10% of patients whose prostate cancer and lymph nodes are removed through robot-assisted keyhole surgery require treatment for symptoms caused by lymphatic fluid collecting in the pelvis, known as lymphocele, which can also be seen in nearly a third of patients when they were systematically checked, without them reporting symptoms.

Symptoms of lymphocele include reinfections, pelvic pain, bladder pressure, and swollen legs due to vein compression are some of the symptoms. Symptomatic lymphocele, if left untreated, can lead to difficult-to-treat serious infections or deep vein thrombosis.

Urology specialist Manuel Neuberger from University Medical Centre Mannheim and Heidelberg University said, “When they have just returned home following a cancer operation, the last thing patients need is to return to the hospital with this kind of complication, which unfortunately is fairly common.”

If drainage does not cure the problem, in rare cases, the final treatment is to create an artificial opening in the peritoneum, which provides a route out for the lymph, so it is no longer stuck in the pelvis,” he added.

“As it is such a simple step, why not create a flap as standard to prevent the condition in the first place,” he asked.

As previous studies of the technique had been inconclusive, the researchers designed the current trial as larger to ensure findings were statistically significant, Manuel explained.

The trial involved over 550 patients and four different surgeons working at University Medical Centre Mannheim, who were only informed whether a patient was to have a peritoneal flap once the rest of the operation had been completed. During the six-month follow-up period, only ten patients in the peritoneal flap group had developed a symptomatic lymphocele, compared to 25 in the control group. During discharge, 20 patients in the flap group had lymphocele with no symptoms, compared to 46 in the control group. During the follow-up, this had risen to just 27 in the flap group but 74 in the control group.

Professor Philip Nuhn, Professor of Urology at University Medical Centre Mannheim, who led the research, said, “Using the peritoneal flap reduced the incidence of lymphocele from nine per cent to less than four per cent. We now use this as the new standard in Mannheim, and hope that, following these results, it will become common practice elsewhere as well.”

Professor Jochen Walz, from the EAU Scientific Congress Office and the Institut Paoli-Calmettes Cancer Center in Marseille, said, “Most problems in these operations are linked to the lymph node removal, rather than the prostate surgery itself. Removal of the lymph nodes allows us to see if cancer has spread, so it is important to do, particularly as surgery is now mainly used in higher-risk patients. Creating a peritoneal flap is a simple, small, easy and quick procedure that takes about five minutes to complete. It is totally safe and this trial has shown it can substantially reduce complications, so there’s no reason why surgeons should not now do this as standard.

“Randomised control trials to evaluate technical changes in surgery are notoriously difficult to do – but this study has shown that they are both possible and effective. That’s good news for surgeons and patients, who will benefit from better outcomes as a result.”