The Retroperitoneal Laparoscopic Renal Capsulectomy for Spontaneous Renal Subcapsular Fluid Collection: A Case-Series Report and Literature Review

Abstract

Spontaneous renal subcapsular fluid collection may occur as a rare presentation of nephritic syndrome, and distension of the renal capsula and Gerota fascia due to massive fluid accumulation may cause pain. In addition, hypertension secondary to renal ischemia and activation of renin-angiotensin-aldosterone system may also occur. The objective of this study is to evaluate the surgical outcome of retroperitoneal laparoscopic renal capsulectomy for patients with this disease.We retrospectively analyzed the clinical data of 10 female patients with spontaneous renal subcapsular fluid collection, diagnosed with B ultrasound and enhanced computed tomography (CT) scan. Eight patients first underwent percutaneous renal subcapsular drainage, which seemed to be less effective, and then all patients underwent retroperitoneal laparoscopic renal capsulectomy. The volume of renal subcapsular fluid was documented, the fluid was examined by routine biochemical tests, and the excised renal capsules underwent pathological examination individually. The postoperative drainage time for each patient was documented, and follow-up was conducted 1, 3, 6, 12 months, and 2 years postoperatively.Retroperitoneal laparoscopic renal capsulectomy was successfully performed in all patients with no major complications. The average volume of renal subcapsular fluid was 436 milliliter (mL, 180-880 mL) in light yellow color, and the concentration of creatinine and urea nitrogen was quite similar to that of serum. The pathological findings revealed fibrous dysplasia of the renal capsule with chronic infiltration of inflammatory cells. The average drainage time was 11.5 days (5-30 days) postoperatively. All patients recovered 1 month after the operation and there were no recurrences with a mean follow-up period of 12 months (6-24 months).The reason for spontaneous renal subcapsular fluid collection is unknown, and the aim of treatment is mainly to alleviate symptoms. In our experience, retroperitoneal laparoscopic renal capsulectomy is an effective surgical treatment, especially for patients who were refractory to percutaneous renal subcapsular drainage, with no observed recurrence.

FIGURE 1

CT scan images before and after retroperitoneal laparoscopic renal capsulectomy for 3 individual patients with spontaneous renal subcapsular fluid collection. The contrast CT scan for patient #2 showed spontaneous renal subcapsular fluid collection with the maximum length of 9.0 cm in the right kidney, which largely regressed 1 month after the operation as demonstrated by CT scan. Patient #5 had spontaneous renal subcapsular fluid collection with a maximum length of 10.0 cm in the left kidney, 3 months after surgery, CT scans showed complete clinical regression. Patient #9 had spontaneous renal subcapsular fluid collection in both kidneys with a notably larger diameter of 15.5 cm on the left side; 6 months after retroperitoneal laparoscopic left renal capsulectomy, fluid collection almost disappeared in the left kidney. CT = computed tomography.

FIGURE 2

Retroperitoneal laparoscopic renal capsulectomy in a patient with spontaneous renal subcapsular fluid collection. The laparoscopic puncture needle suction was inserted into the surface of the diseased renal capsula (A). The renal capsula was opened by a laparoscopic hook electrode, and renal subcapsular fluid of light yellow color could be observed (see arrow, B). The renal capsule was further incised by the laparoscopic ultrasonic dissector (C), and the pale renal parenchyma could be observed from the opened capsula (see arrow, D).

FIGURE 3

The 4 representative pathological images of excised renal capsula were examined by hematoxylin-eosin staining with ×40 magnification. Fibrous dysplasia of the renal capsula could be observed with infiltration by inflammatory cells (see arrows) together with old hemorrhage foci in some areas (see stars).