Unroofingをおこなった腎杯憩室の1例

Abstract

Twenty-year-old nursing school student visited the hospital with complaints of left flank pain, fever and hematuria. Antibiotic therapy improved these symptoms. KUB showed multiple small calculi in the left renal area. Findings of DIP and RP were as follows. A round large cystic-like lesion was seen in the middle anterior renal parenchyma on the left side which contained before-mentioned multiple small calculi and communicated with an upper calyx. Renal arteriography demonstrated a poor vascularity of the area of this cystic-like lesion. From these clinical data, preoperative diagnosis was made as an infected calyceal diverticulum with calculi. At operation, there was a dense adhesion on the diverticular wall which was teared along the junction with the normal parenchyma and slight turbid fluid with calculi effluxed during procedure. No apparent functioning renal parenchyma was recognized in this thin dome of diverticular wall, which was reflexed to the peritoneal side without removal of it. These procedures could be said as almost same operative method against simple renal cyst, which is usually called an unroofing. Large cavity appeared after excision of top of the diverticular wall. An opening leading from the cavity to the upper calyx was demonstrated with using a ureteral catheter. Next we began to attempt a partial nephrectomy or a total resection of residual diverticular wall adherent to the normal parenchyma, but stopped performing it, because these procedures seemed to have a great risk of secondary nephrectomy in our case. No attempt was made to approximate the wall of the diverticular cavity, because which was too large for perfect approximation. Biopsy of bottom of diverticular wall was made. Hemostatic suture of plain catgut was placed along the cut margin, uniting the wall of the diverticular remnant to the renal capsule. Complete obliteration of the communicating tract was made with 0000 Dexon. Wound was closed with drain. Microscopic examination of the biopsied specimen could not reveal the transitional cell lying of the diverticular wall. However, it could be said, that in patient with infection and/or stones, epithelial tissue might shows a fibrosis or desquamation, like in our case. There was a reluctant to accept these operative procedures because the entire pathologic diverticular wall was not removed and its cavity was not approximated. The question arised as to where infection might recur or the residual diverticular wall adherent to the normal parenchyma might continue to secrete the urine. But, postoperatively, there was no urinary leakage from the wound. Patient had an uneventful course except a slight fever of two weeks duration. Postoperative IVP showed good functional and anatomical appearance of the left kidney. She is being well four months since the operation. No postoperative urinary leakage from the wound means that there is a free communication between the calyx and the cavity of diverticulum, but no tubulus open into it. Moreover, this might suggest hypothesis of calyceal diverticulum proposed by Middletone, that is, the formation of calyceal diverticulum would be for one of the middle or later generation branches to fail to influence the formation of a renal vesicle but rather to continue to grow out into the renal parenchyma for a distance and then spawn several generations of branches which later consolidate into a single cavity under the influence of back flow of urine from the connecting renal pelvis or calyx. We collected 148 reported cases of operative therapy of calyceal diverticulum in Japanese literature. Several methods have been described in the surgical intervention to the calyceal diverticulum, and consisted of partial nephrectomy, the most favorite method, in 81 cases (55%), primary nephrectomy in 29 cases (20%), diverticulectomy in 26 cases (18%), secondary nephrectomy in 5 cases (3%) and so on. Calyceal diverticulum is an almost always a benign lesion. Conserving and salvaging operation of the kidney would be a plausible aim in• this lesion. If there were a large diverticulum situated in the middle portion of the kidney just like in our case, and there seems not to perform a partial nephrectomy or diverticulectomy without a great risk of resultant secondary nephrectomy, unroofing of diverticular wall and obliteration of communicating tract would be a treatment of choice for renal conservative operation.