Background Laparoscopic adrenalectomy is an accepted treatment worldwide for adrenal gland disease in adults. The transperitoneal approach is more common. The retroperitoneal approach may be preferred, to avoid entering the peritoneum, but no clear advantage has been demonstrated so far. Objectives To assess the effects of laparoscopic transperitoneal adrenalectomy (LTPA) versus laparoscopic retroperitoneal adrenalectomy (LRPA) for adrenal tumours in adults. Search methods We searched CENTRAL, MEDLINE, Embase, ICTRP Search Portal, and ClinicalTrials.gov to 3 April 2018. We applied no language restrictions. Selection criteria Two review authors independently scanned the abstract, title, or both sections of every record retrieved to identify randomised controlled trials (RCTs) on laparoscopic adrenalectomy for preoperatively assessed adrenal tumours. Participants were affected by corticoid and medullary, benign and malignant, functional and silent tumours or masses of the adrenal gland, which were assessed by both laboratory and imaging studies. Data collection and analysis Two review authors independently extracted data, assessed trials for risk of bias, and evaluated overall study quality using GRADE criteria. We calculated the risk ratio (RR) for dichotomous outcomes, or the mean difference (MD) for continuous variables, and corresponding 95% confidence interval (CI). We primarily used a random-effects model for pooling data. Main results We examined 1069 publications, scrutinized 42 full-text publications or records, and included five RCTs. Altogether, 244 participants entered the five trials; 127 participants were randomised to retroperitoneal adrenalectomy and 117 participants to transperitoneal adrenalectomy. Two trials had a follow-up of nine months, and three trials a follow-up of 31 to 70 months. Most participants were women, and the average age was around 40 years. Three trials reported all-cause mortality; in two trials, there were no deaths, and in one trial with six years of follow-up, four participants died in the LRPA group and one participant in the LTPA group (164 participants; low-certainty evidence). The trials did not report all-cause morbidity. Therefore, we analysed early and late morbidity, and included specific adverse events under these outcome measures. The results were inconclusive between LRPA and LTPA for early morbidity (usually reported within 30 to 60 days after surgery; RR 0.56, 95% CI 0.27 to 1.16; P = 0.12; 5 trials, 244 participants; very low-certainty evidence). Nine out of 127 participants (7.1%) in the LRPA group, compared with 16 out of 117 participants (13.7%) in the LTPA group experienced an adverse event. Participants in the LRPA group may have a lower risk of developing late morbidity (reported as latest available follow-up; RR 0.12, 95% CI 0.01 to 0.92; P = 0.04; 3 trials, 146 participants; very low-quality evidence). None of the 78 participants in the LRPA group, compared with 7 of the 68 participants (10.3%) in the LTPA group experienced an adverse event. None of the trials reported health-related quality of life. The results were inconclusive for socioeconomic effects, assessed as time to return to normal activities and length of hospital stay, between the intervention and comparator groups (very low-certainty evidence). Participants who had LRPA may have had an earlier start on oral fluid or food intake (MD -8.6 hr, 95% CI -13.5 to -3.7; P = 0.0006; 2 trials, 89 participants), and ambulation (MD -5.4 hr, 95% CI -6.8 to -4.0 hr; P < 0.0001; 2 trials, 89 participants) than those in the LTPA groups. Postoperative and operative parameters (duration of surgery, operative blood loss, conversion to open surgery) showed inconclusive results between the intervention and comparator groups. Authors' conclusions The body of evidence on laparoscopic retroperitoneal adrenalectomy compared with laparoscopic transperitoneal adrenalectomy is limited. Late morbidity might be reduced following laparoscopic retroperitoneal adrenalectomy, but we are uncertain about this effect because of very low-quality evidence. The effects on other key outcomes, such as all-cause mortality, early morbidity, socioeconomic effects, and operative and postoperative parameters are uncertain. LRPA might show a shorter time to oral fluid or food intake and time to ambulation, but we are uncertain whether this finding can be replicated. New long-term RCTs investigating additional data, such as health-related quality of life, surgeons' level of experience, treatment volume of surgical centres, and details on techniques used are needed.
