Renal cell carcinoma in horseshoe kidney treated with retroperitoneoscopic partial nephrectomy: A case report

Abstract

Horseshoe kidney complicated with renal malignancy is rare, the incidence and prognosis are not much different from those in the general population, However, due to the unique anatomical characteristics of the horseshoe kidney, the partial nephrectomy of horseshoe kidney is difficult and challenging. A 41-year-old female who incidentally found a right kidney 59 mm ∗ 45 mm solid mass combined with a horseshoe kidney. We successfully performed a retroperitoneal laparoscopic partial nephrectomy. For laparoscopic partial nephrectomy, in order to accurately judge the blood supply of horseshoe kidney and reduce intraoperative bleeding and complications, CT angiography and 3-dimensional (3D) reconstruction are very important.

1 Introduction

Horseshoe kidney is rare in the clinic because of abnormal renal fusion, and the fusion of two kidney lower poles is similar to a horseshoe shape, with an incidence of about 0.25–0.5 %. Concurrent malignancy of the horseshoe kidney is rare, with an incidence of approximately 5 %–13 %. Renal cell carcinoma (RCC) is a malignant renal tumor with the highest incidence of horseshoe kidney, accounting for approximately 50 % of horseshoe kidney and kidney tumors. However, its incidence and prognosis are indistinguishable from those in the general population. According to the literature, fewer than 300 cases of horseshoe kidney cancer have been reported worldwide, and the vast majority of individual reports have been reported because of the anatomical variation of the horseshoe kidney. The surgery is more complicated and difficult, and in November 2023, we performed retroperitoneal laparoscopic partial nephrectomy for horseshoe kidney carcinoma.

2 Case presentation

A 41-year-old woman who accidentally had a tumor of her right kidney and a horseshoe kidney. Ultrasound and enhanced revealed a 59 mm ∗ 45 mm occupying lesion in the right lower pole of the horseshoe kidney, considering renal cancer ( Fig. 1 ). CT angiography and 3D reconstruction showed the tumor location and arterial vessels, the main renal artery, except in the renal fusion site. The tumor was located in the lower pole of the right kidney and protruding ( Fig. 2 ), with no evidence of tumor metastasis or lymph node lesions, and no vascular or renal aggregate system involvement.R.E.N.A.L score of 10p. The tumor was removed via laparoscopic partial nephrectomy using a retroperitoneal approach.

Under general anesthesia, the patient placed in the left lateral position, the silicone was placed under the armpit side of the waist, and the operating bed was adjusted to the head low and foot position, raised and exposed the right waist position. The retroperitoneal cavity was used to cut about 20 mm under the costal margin of the posterior axillary line 12, and the lumbar and dorsal fascia was punctured with the tip of a vascular clamp to enter the retroperitoneal space. After the space was enlarged by fingers, an air sac was inserted, injected air into the airbag about 500 ml to expand the retroperitoneal space, the observation hole was located at the middle line of the axillary above the iliac spine, and a 10 mm trocar was inserted. After the pneumoperitoneum was confirmed,a 10 mm trocar was inserted in the axillary front,a 12 mm trocar was inserted in the posterior axillary line incision, and a 5 mm trocar was inserted into the middle of the anterior and posterior trocars. After removing the extraperitoneal adipose tissue, the Gerota fascia was opened to find the main renal artery in the right renal hilum ( Fig. 3 a), separated the accessory renal artery in the right isthmus area ( Fig. 3 b), the adhesive tissue around the tumor was fully released, and the tumor was exposed, and the cutting margin was marked at the junction between the tumor and the renal parenchyma ( Fig. 3 c). The 3-0 and 2-0 barbed sutures were prepared in advance, and a Hem-o-lok suture was placed at the tail end. The two renal arteries were clamped separately, the renal parenchyma was cut along the marked line, and the tumor was completely removed using blunt scissors and sharp along the tumor capsule ( Fig. 3 d). The renal parenchymal wound was sutured in two layers. First, the renal collection system and bleeding point were sutured with 3-0 barbed suture. In the second layer, the renal parenchymal was closed with 2-0 barbed suture ( Fig. 3 e), and the tail end of the line was fixed with Hem-o-lok. The vessel clip was removed, the renal artery was opened to restore blood supply to the kidney, the wound surface was checked without active bleeding, and the tumor capsule was intact. The specimen was placed in the specimen bag, the posterior axillary line incision was extended, the specimen was removed, the drainage tube was placed from the midline axillary hole, the operative time was 130 min, the renal thermal ischemia time was 26 min, the intraoperative blood loss was approximately 200 ml, and the drain was removed on the fifth postoperative day and was successfully discharged on day 7. Pathological examination confirmed clear cell carcinoma-grade RCC pT1b Fuhrman II with a negative surgical margin. The patient was followed up for more than a year, with no evidence of tumor recurrence or metastasis and no evidence of renal atrophy.