URINOTHORAX FOLLOWING THE FORMATION OF A NEPHROPLEUROCUTANEOUS FISTULA AFTER PERCUTANEOUS NEPHROLITHOTOMY TO REMOVE STAGHORN CALCULI

Abstract

TOPIC: Disorders of the Pleura TYPE: Medical Student/Resident Case Reports INTRODUCTION: Urinothorax is a rare cause of pleural effusion secondary to obstructive uropathy or a complication of a post urological procedure. Patients may present with respiratory and urinary symptoms. Pleural fluid analysis is traditionally transudative and the pleural fluid to serum (PF/S) creatinine ratio is greater than 1. Imaging can also be done to find the etiology while treatment of the underlying pathophysiology typically results in its resolution. CASE PRESENTATION: A 27-year-old female with history of nephrolithiasis secondary to proteus mirabilis infection presented to the emergency room with SOB and CP six days after undergoing a left ureteral stent placement alongside a left percutaneous nephrolithotomy (PCNL) in order to remove a staghorn calculi measuring 9.2cm x 3.2cm.Initial chest x-rays revealed a large, left-sided pleural effusion. A diagnostic thoracentesis was performed and 800cc of cloudy, yellow fluid was removed. Pleural fluid analysis revealed a PF/S creatinine ratio of 2.7 and pleural LDH of 208. Since these findings were consistent with an LDH-discordant urinothorax, a Foley catheter was placed; however, the patient began to develop fevers and left flank pain. A CT scan revealed left upper pole hydronephrosis, a newly-formed left renal pelvis stone causing stent obstruction, and the presence of a nephropleurocutaneous tract likely secondary to the PCNL. The patient was then taken to the OR for stent revision and chest tube placement. Within the next few days, her respiratory status improved and she was discharged home with close follow-up. DISCUSSION: Urine translocation into the pleural space occurs in two ways. The first comes from the lymphatic drainage of urine that has been extravasated into the retroperitoneal space because of increased pressure gradients from obstructive uropathy. The second, which is what our patient had, comes from the urine entering into the pleura through a fistula or an anatomical defect. A diagnostic thoracentesis of a urinothorax will reveal a cloudy, yellow fluid with the smell of urine, a PF/S creatinine ratio greater than 1, and a transudate. However, studies have shown that concomitant infections, such as our patient's proteus mirabilis infection, can cause the fluid to be exudative. Imaging can also be used to further identify the pleural effusion as well as any pathological or structural abnormalities. Treatment of a urinothorax depends on the underlying etiology. For obstructive cases, stents, nephrostomy tubes, and Foley catheters are utilized. For iatrogenic cases like our patient's, repairing the defect yields the best results. CONCLUSIONS: The identification of a urinothorax following a post urological procedure requires a high level of clinical suspicion in the correct clinical context. As such, it is important for clinicians to learn more about this rare cause of pleural effusions, its pathophysiology, and its treatment options. REFERENCE #1: Toubes, M., Lama, A., Ferreiro, L., Golpe, A., Álvarez-Dobaño, J., & González-Barcala, F. et al. (2017). Urinothorax: a systematic review. Journal Of Thoracic Disease, 9(5), 1209-1218. https://doi.org/10.21037/jtd.2017.04.22 REFERENCE #2: Austin, A., Jogani, S., Brasher, P., Argula, R., Huggins, J., & Chopra, A. (2017). The Urinothorax: A Comprehensive Review With Case Series. The American Journal Of The Medical Sciences, 354(1), 44-53. https://doi.org/10.1016/j.amjms.2017.03.034 REFERENCE #3: Ramahi, A., Aburayyan, K., Alqahtani, A., Said Ahmed, T., & Taleb, M. (2019). Shortness of Breath: An Unusual Presentation of Bladder Injury. A Case Report and Literature Review of Urinothorax. Cureus. https://doi.org/10.7759/cureus.4559 DISCLOSURES: No relevant relationships by Sanford Church, source=Web Response No relevant relationships by Timothy Vu, source=Web Response No relevant relationships by Bassam Yaghmour, source=Web Response, value=Honoraria Removed 04/30/2021 by Bassam Yaghmour, source=Web Response