Successful Treatment of Idiopathic Chyluria by Direct Percutaneous Puncture and Embolization of the Fistula Site: A Case Report

Abstract

We report a case of idiopathic chyluria in a woman in her 70s, successfully treated by direct percutaneous puncture and embolization of the fistula site. The patient had experienced persistent milky-white urine, progressive weight loss, and voiding difficulties for >3 years. Inguinal intranodal lymphangiography identified a lymphatic-urinary fistula near the lower pole of the left renal calyx. Later, under fluoroscopic guidance, the fistula site was directly punctured and embolized using n-butyl cyanoacrylate without complications. Her symptoms resolved immediately, and there has been no recurrence over a two-year follow-up period while she remained on a regular diet. This case highlights the effectiveness of direct percutaneous embolization of the fistula site as a minimally invasive treatment option for refractory chyluria.

Introduction

Chyluria is the presence of lymphatic fluid in the urine due to an abnormal communication between the lymphatic system and the urinary tract [1]. In endemic regions, it is primarily caused by filariasis, while in non-endemic areas, idiopathic or secondary causes such as congenital lymphatic malformations, trauma, malignancies, and postoperative changes are more common [2, 3]. Conservative treatment with a low-fat diet is the first-line approach, although its curative potential is limited. Retrograde sclerotherapy using agents such as silver nitrate or dextrose may also be performed via the transurethral route; however, these treatments often require multiple sessions and carry risks such as hematuria and ureteral strictures [1]. Surgical interventions, such as lymphatic-urinary tract disconnection or renal pedicle lymphatic ligation are considered in refractory cases but are invasive and associated with potential complications [3]. In recent years, interventional radiology procedures have also been applied [4-8], including interstitial lymphatic embolization via puncture of lymph nodes or lymphatic vessels surrounding the fistula [5, 6]. Here, we report a case in which treatment was successfully achieved by embolization through direct puncture of the fistula site.

Case Presentation

A woman in her 70s with no identifiable underlying cause presented with chyluria lasting >3 years. Initial conservative treatment with a low-fat diet was ineffective. She experienced progressive weight loss and worsening urinary symptoms. Laboratory tests showed hypoalbuminemia (albumin: 2.4 g/dL), low total protein (4.4 g/dL), and proteinuria (0.854 g/day). Cystoscopy revealed chylous efflux from the left ureteral orifice. Retrograde pyelogram demonstrated reflux of contrast material around the lower calyx of the left kidney into the lymphatic vessels (Figure 1), which is a finding often observed in chyluria [9, 10]. Under ultrasound guidance with a linear probe (Xario200; Canon Medical Systems, Tokyo, Japan), inguinal intranodal lymphangiography was performed from the inguinal lymph nodes, using a single-plane system (Infinix Celeve-i; Cannon Medical Systems, Tokyo, Japan). Using 23 G local anesthesia needles (Cathelin needle; Terumo Corp., Tokyo, Japan), one lymph node on each side was punctured from the caudal side at an angle nearly parallel to the skin. After injection of a small amount of lidocaine, a total of 5 mL of Lipiodol Ultra Fluid (Guerbet Japan K.K., Tokyo, Japan) was injected, and the lymphangiogram demonstrated a fistula near the lower pole of the left renal calyx (Figure 2a), while subsequent CT performed 2 hours later showed focal Lipiodol accumulation in that area (Figure 2b). No abnormalities were observed in the thoracic duct or cisterna chyli, and CT confirmed the arrival of Lipiodol up to the left venous angle. Since symptoms persisted, percutaneous lymphatic embolization was performed 2 months later. Premedication included intravenous acetaminophen (Acelio, Terumo Corporation, Tokyo, Japan) and hydroxyzine hydrochloride (Atarax-P, Pfizer, Tokyo, Japan). After intranodal lymphangiography (Figure 3a), following a small amount of local anesthesia with lidocaine, a 21-gauge Chiba needle (P.T.C.D set, Top, Tokyo, Japan) was advanced to the fistula site under fluoroscopic guidance using the bull's-eye technique, inserted almost perpendicular to the body axis. Although the fistula site moved with respiratory motion of the kidney, successful puncture was achieved in a single attempt by controlling the patient's breath-hold. A small amount of contrast agent (Iopamidol, Fuji Pharma Co., Ltd., Tokyo, Japan) was injected to confirm flow into the lymphatic vessels. After flushing with a small volume of 5% glucose solution, a 1.5 mL mixture of n-butyl cyanoacrylate (NBCA, Histoacryl, B. Braun, Melsungen, Germany) and Lipiodol (1:1 ratio) was injected, opacifying the lymphatic vessels up to the renal calyx (Figures 3b and c and Supplementary Material 1). Mild pain was noted during needle insertion and embolization, but no other complications occurred. The chyluria resolved immediately, and the patient resumed a regular diet the following day with no recurrence. At the 3-month follow-up, serum protein levels had normalized (Total Protein: 6.5 g/dL, albumin: 3.9 g/dL, urine protein: 0.003 g/day), and she has remained asymptomatic for >2 years.

Figure 1.

Retrograde pyelogram demonstrates reflux of contrast medium around the lower pole calyx of the left kidney (arrow) into the lymphatic vessels (arrowheads).

Figure 2.

Inguinal intranodal lymphangiogram shows a fistula near the left lower pole calyx (arrow) (a) with focal Lipiodol accumulation at the site seen on CT performed 2 hours later (arrow) (b).

Figure 3.

The fistula site (arrow) (a, b, c) near the left lower pole calyx is punctured with a 21 G needle (bull’s-eye view) (dotted circle) and embolized with 1.5 mL of 50% NBCA (b). Embolic material is visualized in the lymphatic vessels and renal calyx (arrowhead) (b), confirmed by CT (c). The expected puncture line is indicated with a dashed line (c).

Discussion

In recent years, a limited but increasing number of reports have described image-guided interventional radiology techniques for the treatment of chyluria. Intranodal lymphangiography is useful not only for the precise localization of lymphatic leaks but may also occasionally lead to resolution [4]. Additionally, interstitial lymphatic embolization―which involves direct puncture and embolization of lymphatic vessels or nodes surrounding the fistula―has been reported to be effective, even in congenital cases [5, 6]. However, multiple embolization sessions are often necessary. Nguyen et al. [7] introduced balloon-assisted interstitial embolization, in which a balloon catheter is retrogradely advanced into the thoracic duct via the lymphovenous junction, followed by direct puncture and embolization of lymphatic vessels. This technique improves safety and efficacy by preventing reflux of embolic material into the thoracic duct [7]. Furthermore, although thoracic duct stenting has been reported to relieve lymphatic congestion, Hoa et al. [8] described a case of recurrent chyluria due to stent occlusion that was successfully treated with renal-lymphatic fistula embolization. These findings underscore the importance of directly embolizing the lymphatic-urinary fistula in selected cases. In our case, embolization was performed because symptoms did not improve with intranodal lymphangiography alone. In the intranodal lymphangiograms (Figures 2a and 3a), no lymph nodes were observed around the fistula, and the fistula appeared larger than the surrounding lymphatic vessels. Therefore, we directly punctured and embolized the fistula site, resulting in complete resolution of symptoms after a single session.

Conclusion

In idiopathic chyluria, when the lymphatic-urinary fistula is clearly visualized by intranodal lymphangiography, direct percutaneous puncture and embolization of the fistula site can be one of the safe, effective, and durable treatment option. This case demonstrates the utility of image-guided targeted embolization as a minimally invasive alternative to surgical intervention.

Author Contributions

TY: Substantial contributions to the conception or design of the work; AND the acquisition, analysis, AND interpretation of data for the work; AND Drafting the work; AND Final approval of the version to be published; AND Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

SM: Substantial contributions to the conception or design of the work; AND the acquisition, analysis, AND interpretation of data for the work; AND Drafting the work; AND Final approval of the version to be published; AND Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

AI: Substantial contributions to the acquisition of data for the work; AND Revising the work critically for important intellectual content; AND Final approval of the version to be published; AND Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

TK: Substantial contributions to the acquisition of data for the work; AND Revising the work critically for important intellectual content; AND Final approval of the version to be published; AND Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

YK: Substantial contributions to the acquisition of data for the work; AND Revising the work critically for important intellectual content; AND Final approval of the version to be published; AND Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

SE: Substantial contributions to the acquisition of data for the work; AND Revising the work critically for important intellectual content; AND Final approval of the version to be published; AND Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

HY: Substantial contributions to the acquisition of data for the work; AND Revising the work critically for important intellectual content; AND Final approval of the version to be published; AND Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

KY: Substantial contributions to the acquisition of data for the work; AND Revising the work critically for important intellectual content; AND Final approval of the version to be published; AND Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

TT: Substantial contributions to the acquisition of data for the work; AND Revising the work critically for important intellectual content; AND Final approval of the version to be published; AND Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

SS: Substantial contributions to the acquisition of data for the work; AND Revising the work critically for important intellectual content; AND Final approval of the version to be published; AND Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Conflicts of Interest

There are no conflicts of interest.

Ethical Statement

This case report was conducted in accordance with the principles of the Declaration of Helsinki. The institutional review board approval was waived because this is a single-patient case report that does not contain identifying information.

Supplementary Material

Supplementary Material 1

Fluoroscopic video in the left anterior oblique view during embolization (accelerated playback).

NBCA can be seen filling the lymphatic vessels and the lower renal calyx from the fistula site.