Case of the Month from University of Melbourne, Australia: refractory chyle leak after retroperitoneal lymph node dissection with updated algorithm

Abstract

Retroperitoneal lymph node dissection (RPLND) is an important part of multimodal therapy for node-positive germ cell malignancy [1-4]. However, due to wide heterogeneity in patient status, disease biology and tumour locations, RPLND can be challenging and risky [1]. One such risk is iatrogenic chylous ascites (CA; 8% of cases) [1]. CA is defined as accumulation of chyle, a lipid-rich lymph fluid in the peritoneal cavity [5]. Morbidity from intra-abdominal chyle extravasation includes delayed wound healing, malnutrition, electrolyte disturbances, and immunosuppression [2, 6]. This morbidity impairs postoperative recovery, delays adjuvant oncological therapy, and detrimentally affects quality of life [2, 4]. Limited reliable data exist to describe the management of this complex condition [1]. We outline a difficult case and then review the literature for treatment strategies and propose a contemporary management algorithm for refractory post-RPLND CA. A 32-year-old male presented with a testicular mass. Left orchidectomy revealed a mixed germ cell tumour comprising embryonal carcinoma, seminoma, and yolk sac tumour (pT2). Four cycles of bleomycin, etoposide and platinum (BEP) chemotherapy were administered. Subsequent CT showed residual retroperitoneal lymphadenopathy (2.5 cm). Salvage robotic RPLND was performed and the patient was discharged well on postoperative day 1. Subsequent pathology revealed 10 out of 16 lymph nodes were positive, with the largest viable deposit measuring 19 mm. Lymphovascular invasion was present, but extranodal extension was absent. The postoperative period initially progressed without complications. However, the patient presented again to the emergency department 5 days postoperatively with abdominal pain and ascites. He was admitted for paracentesis (10 L), which led to a diagnosis of chyle leak (Fig. 1). This was complicated and likely compounded by adjuvant paclitaxel, ifosfamide and cisplatin (TIP) chemotherapy [5]. Despite protocol-guided dietary adjustments and a short-chain fatty acid regimen (outlined by a dietician, with structured <20 g fat per day monitored by diet-tracking mobile application), and somatostatin analogue octreotide (200 mcg, s.c., three times daily), limited improvement was observed in managing the chyle leak [7]. Symptomatic re-accumulation required a total of eight ultrasonography-guided paracentesis procedures at approximately weekly intervals. Once the volume drained with these frequent procedures had plateaued for 6 weeks (~10 L), it was deemed to be refractory CA. At this stage, a lymphoscintigram was conducted, demonstrating chyle leak from the left para-aortic region at L1/L2, and from a right groin lymph node (Fig. 2). After further multidisciplinary discussions, glue embolization was performed. Initial embolization via inguinal nodal injection was unsuccessful, however, a subsequent retrograde thoracic duct lymphangiogram proved successful. A tap drain was placed after enabling discharge with functioning drain (Fig. 3). Three months post-lymphangiogram and embolization, the abdominal drain was removed due to pain and reduced output (<50 mL per day for 2 consecutive days), with full diet tolerance. Subsequently, the patient's CA has resolved. Prompt identification and treatment of CA is essential for optimal surgical outcomes. Refractory CA (defined as 4 weeks of plateaued progress on current level of management) is associated with high morbidity and requires multimodal management. High-volume RPLND centres should have a management protocol for this uncommon complication (Fig. 4). Once diagnosed with CA, clinical assessment (examination and imaging) with elevated triglycerides in paracentesis fluid, we recommend commencement of a multimodal management plan with multidisciplinary involvement (senior dietician and provision of a patient information booklet on strict dietary guidelines about fat reduction). This includes a medium-chain fatty acid diet with a somatost