Radiological lymphoceles and clinically relevant lymphatic complications after retroperitoneal lymph node dissection...

Postoperative lymphoceles are recognized complications of retroperitoneal lymph node dissection (RPLND) for testicular germ cell tumours (TGCT). Previous studies have predominantly reported symptomatic or intervention-requiring lymphoceles, whereas the incidence, temporal evolution, and clinical relevance of lymphoceles on postoperative imaging remain poorly defined. We evaluated radiologically detected lymphoceles and clinically relevant lymphatic complications after post-chemotherapy RPLND (PC-RPLND) using routine serial imaging.

This retrospective single-centre cohort study included 86 consecutive patients who underwent PC-RPLND under a standardized perioperative management protocol. Postoperative imaging consisted of ultrasound at postoperative day 5-7 and 3-4 weeks, followed by computed tomography at 3 and 12 months. The primary endpoint was the incidence of any imaging-detected lymphocele during follow-up. Secondary endpoints included lymphocele prevalence at each imaging time point, clinically relevant lymphatic complications, postoperative complications, and exploratory factors associated with lymphocele formation.

Of 86 included patients, 85 were evaluable for the primary endpoint. Overall, 46 patients (54.1%) had at least one imaging-detected lymphocele during follow-up. Lymphoceles were most frequently detected at discharge (36/84, 42.9%) and decreased over time to 32.8% (19/58) at 3-4 weeks, 31.5% (17/54) at 3 months, and 15.8% (9/57) at 12 months. Clinical follow-up was available for 65 patients. Clinically relevant lymphatic complications occurred in only 3 patients (4.6%), comprising two cases of lymphatic/chylous ascites and one lymphatic fistula associated with a small precaval lymphocele. Among 49 patients with paired 3- and 12-month CT, 10 of 16 lymphoceles present at 3 months had resolved by 12 months, whereas only one was newly detected (exact McNemar p = .012). Exploratory analyses identified no significant associations between imaging-detected lymphocele formation and patient characteristics, tumour-related factors, surgical approach, or extent of lymphadenectomy.

Lymphoceles are frequently detected by routine serial imaging after PC-RPLND but rarely translate into clinically relevant lymphatic morbidity. Radiologically detected lymphoceles should therefore be distinguished from clinically relevant lymphatic complications when interpreting surveillance imaging, counselling patients, and reporting postoperative outcomes after RPLND.