Prevention of conversion in posterior retroperitoneal adrenalectomy by measuring pre-operative anatomical conditions on cross-sectional imaging (computerised tomography or magnetic resonance imaging)

BACKGROUND: In addition to the common laparoscopic lateral transperitoneal adrenalectomy (LTA), the posterior retroperitoneal adrenalectomy (PRA) is becoming increasingly important. Both techniques overlap in their indication, resulting in uncertainty about the preferred approach in some patients. We hypothesise that by determining anatomical characteristics on cross-sectional imaging computerised tomography or magnetic resonance imaging, we can show the limitations of the PRA and prevent patients from being converted to LTA. METHODS: This retrospective study includes 14 patients who underwent PRA (n = 15) at a single institution between 2016 and 2018. Previously described parameters such as the retroperitoneal fat mass (RPF) were measured on pre-operative imaging. We compared data from one patient who had a conversion with those from 13 patients without conversion. Furthermore, we explored the influence of these parameters on the operative time. RESULTS: Conversion to LTA was necessary during 1 PRA procedure. Fourteen PRAs in 13 patients were successfully completed. The mean body mass index was 30 kg/m(2) and the mean operation time was 98 min. One patient who underwent a conversion had a substantially higher RPF (25 mm) compared to the patients with successfully completed PRA (median: 5.5 mm [P = 0.001]). Furthermore, the operation time strongly correlated with the RPF (P = 0.004, r = 0.713). CONCLUSIONS: Surgeons can use pre-operative imaging to assess the anatomical features to determine whether a PRA can be performed. Patients with an RPF under 14.3 mm can be safely treated with PRA. In contrast, LTA access should be considered for patients with a higher RPF (>25 mm).