Simple Laparoscopic Nephrectomy in Stone Disease: Not Always Simple

Introduction

Ever since Clayman ¹ made his first laparoscopic nephrectomy public in 1991, the advantages of the laparoscopic approach have been repeatedly confirmed. ^2,3 These advantages comprise shortening of hospital stay, reduction of surgical pain and bleeding, and faster healing of the surgical wound. Unlike radical nephrectomy, simple nephrectomy does not require excision of the adrenal or any adenopathies. Simple nephrectomy is performed in benign pathologies and is the sole valid treatment option in patients with a scarcely functioning lithiasic kidney, causing lumbar pain or repeated urinary infections. Frequently, however, this is not an easy technique owing to the presence of a significant inflammatory, fibrotic, and infectious component. The ultimate presentation in such a scenario is xanthogranulomatous pyelonephritis, accompanied by perirenal fat proliferation that infiltrates the renal fossa structures, including the renal hilum. In some cases, this process gives rise to squamous urothelial cancer. In all these circumstances, intraoperative differentiation of anatomical structures poses a significant challenge to the surgeon.

Here, we report the results of a retrospective study of simple laparoscopic nephrectomy performed in patients with renal stone disease, severely impaired renal function, and perinephric inflammation.

Methods

A retrospective study was carried out for laparoscopic nephrectomy indicated for stone disease between 2006 and 2015 at a hospital that is a reference center for urolithiasis. In all cases, the indication was persistent renal pain and/or infection with a differential renal function below 15% according to DMSA renal scan. Surgery was always performed through the transperitoneal approach, with the first trocar positioned by means of a minilaparotomy under direct vision. Two 10-mm and two 5-mm trocars were usually placed in these cases, and when performing a right nephrectomy, a fifth trocar was used to retract the liver. We used a bipolar coagulation forceps on the left hand, and sometimes a suction probe (Elephant, Coloplast^®) as a blunt dissector. The renal vessels were clipped with Hemolock^®, and 5 mm Ligasure^® was used for small vessel sealing. The kidney was extracted by lengthening the incision of one of the ports or else by a reduced Pfannenstiel approach, according to the patient's characteristics, and the kidney was placed in an Endocatch^®. The lumbar fossa drain was removed after 24 to 48 hours.

Results

During the 9-year period under consideration, 96 simple laparoscopic nephrectomies were carried out for stone disease. The mean patient age was 57 years and 67 (69.7%) of the patients were female. The mean body mass index was 29.4 (range 22–40).

In 62 patients, the left kidney was removed, and in 34 patients, the right kidney was removed. Conversion into open surgery was necessary in seven cases (7.2%) because it proved impossible to dissect the renal hilum owing to xanthogranulomatous pyelonephritis (n = 4) or major associated lesions (n = 3). Mean operative time was 170 minutes. The mean intraoperative bleeding volume was 185 mL, with a range of 50 to 425 mL (except in those patients in whom conversion to open surgery was necessary) (Table 1).

There were several intraoperative complications. Two limited tears of the vena cava resolved with simple hemostasis, and there were two incomplete resections of the juxtaaortic renal pelvis. Complications were assessed as follows using Clavien's classification: 18 patients with Clavien ≤2 and 3 patients with Clavien ≥3. Overall complications rate was 21% (21 patients) (Table 2).

Early reoperations (open access) were performed in three cases: one splenectomy was necessary due to spleen laceration, one case of partial intestinal obstruction necessitated lysis of bowel adhesions (after 72 hours), and one case of pleural perforation necessitated conversion to open surgery for repair. The mean duration of postsurgical hospitalization was 5.4 days. Pathologic assessment revealed chronic pyelonephritis with kidney atrophy and associated pyonephrosis in 85 patients, xanthogranulomatous pyelonephritis in 10 patients, and pT4 squamous cell carcinoma in 1 patient (Table 3).

Spontaneous nephrocutaneous fistulization was seen in three cases: it resolved with conservative treatment in two cases, whereas in one case, abscess debridement was performed by open surgery and the remnants of the upper pole of the kidney 10 months later.

Discussion

There are currently few indications for simple laparoscopic nephrectomy. They include severe renal hypofunction associated with local complications such as pain, symptomatic or recurrent infection, abscess formation, fistulization, and suspected malignant transformation. These scenarios are frequent in patients with stone disease who have lost functionality of the renal unit. Although simple nephrectomy is then the technique of choice, the presence of a significant infectious, inflammatory, and fibrotic component hinders the surgery. Consequently, although the procedure is described (euphemistically) as “simple,” in practice it can be more complex than the radical approach used in oncologic cases.

All of the patients in our series had severely impaired renal function with associated stone disease that required at least one procedure on a renal unit—from placement of a Double-J catheter to percutaneous nephrolithotomy. In many cases, the patients had already undergone more than one operation, either open or endoscopic.

The largest series of nephrectomies in patients with lithiasis are those published by Mao et al. ⁴ with 101 cases and Zelhof and colleagues ⁵ with 142 cases, selected from all the nephrectomies performed in the United Kingdom owing to a benign pathology. Both groups of authors stress the difficulty of such surgery, which was far more frequent among women, exactly as in our series. Zelhof et al. even suggested that the term “simple nephrectomy” should be changed to “benign nephrectomy” since the surgery is anything but simple and in some cases can be difficult.

Quite a number of works have shown that the laparoscopic approach greatly facilitates postsurgical recovery in all its aspects. ^3,6 For this reason, a first attempt through the laparoscopic pathway is always advisable even though, a priori, the radiologic data may indicate that excision of the kidney and the large vessels will be complex. In our series, the laparoscopic approach is intraperitoneal only, but several series have used a retroperitoneal approach that required conversion to open surgery in some cases because of the many subsequent scars in those kidneys. ^{2,3,7 –9}

Xanthogranulomatous pyelonephritis bears the highest degree of technical difficulty and presents a number of risks: opening of the renal capsule, which will make it necessary to continue with the procedure in a subcapsular plane, accidental opening of the urinary pathway with oozing of purulent material into the surgical field, and fragmented kidney excision. Xanthogranulomatous pyelonephritis also involves a greater risk of fistulization both before and after intervention. ^{9 –11}

The loss of anatomical planes hinders the performance of standardized surgery. It is usual for the surgeon to encounter difficulties in the renal hilum due to the presence of bulky adenopathies, infiltration of fat and vessels, absence of a recognizable renal artery, accessory vascularization, and adhesion to bowel and pancreas. The nonexistence of pedicular planes may force block clamping or else first clamping of the renal vein. On the right side, the risk of injuring the vena cava increases the difficulty still further. In our series, we observed two cases of minimal vena cava tearing that were repaired by vascular suturing and did not require conversion to open surgery.

In some instances, fibroses and adhesions make it impossible to locate a cleavage plane between the large vessels and the urinary tract; it is then necessary to excise the kidney and to leave patches of renal pelvis adhered to the aorta or the cava. This will cause no subsequent complications provided that no lithiasic or purulent material is left in the surgical bed.

In more complex cases, it is necessary to convert to open surgery by means of a limited-length lumbotomy, since most of the kidney dissection is already resolved by a previous laparoscopic approach. Pedicle control is directly achieved with vascular clamping and block suture, in some instances using the subcapsular plane. Tobias-Machado and coworkers ¹² suggest a hand-assisted combined approach for those cases in which scar and adhesion release is difficult. In our cases, we always attempt to complete the intended simple laparoscopic nephrectomy, reserving lumbotomy for cases in which this is not feasible.

Of our seven cases involving conversion to open surgery, four showed extensive areas of pyelonephritis, which has proved to be the major risk factor for conversion. Even so, in 6 of the 10 cases of xanthogranulomatous pyelonephritis (60%), we were able to complete the simple laparoscopic nephrectomy, enabling us to declare that this pathology can be approached by laparoscopy in the first instance, always bearing in mind the possible need for conversion. On the basis of their series of 14 simple laparoscopic nephrectomies on xanthogranulomatous kidneys, Guzzo and colleagues ¹¹ share our opinion on the appropriateness of a laparoscopic approach since conversion to open surgery was necessary in only one of their cases (7%). The laparoscopic approach for this stone-related nephrectomy should be done by an experienced urologist.

The most severe immediate complications in our series were (1) a spleen injury caused by a large number of adhesions between the upper renal pole and the spleen that needed reintervention and splenectomy, with a good postoperative outcome, and (2) manifestations of partial intestinal obstruction that were resolved after 48 hours by releasing intestinal loops that had adhered to the renal hilum area. In a third case, a pleural lesion that produces intraoperative pneumothorax, with signs of cardiac tamponade secondary to markedly elevated intrathoracic CO₂ pressure, was effectively treated by lumbotomy with pleural tear repair.

In the two cases in which part of the renal pelvis was left adhered to the aorta (dissection was impossible), the kidney was removed laparoscopically with no intra- or postoperative complications. In these cases it is important to leave neither stone residues nor purulent collections in the surgical bed.

The presence of residual xanthogranulomatosis in the surgical bed as a delayed complication favors fistulization of approaches toward the lumbar area over the months after nephrectomy; this happens through fistulous or nephrotomy tracts that were present before the surgery. In some cases, perirenal infection and inflammation further promote this trend toward fistulization. In our three cases of postnephrectomy lumbocutaneous fistula, antibiotic treatment was effectively applied locally in combination with a 4% eosin solution (to dry the tissues). Reoperation after 10 months was necessary in one case, in which we performed fistulorrhaphy and lumbar fossa curettage; the fistulous process was completely cured.

Conclusions

Simple laparoscopic nephrectomy in patients with stone disease presents a high degree of technical difficulty due to the presence of inflammation, fibrosis, and infection as well as renal and perirenal proliferative tissue. The advantages of the laparoscopic approach are better postsurgical recovery than open surgery and an acceptable rate of major complications. Based on the results published, laparoscopic nephrectomy is the technique of choice in cases of severe renal hypofunction or pyonephrosis secondary to lithiasis, including the presence of xanthogranulomatous pyelonephritis. The latter is the most significant risk factor for conversion to open surgery, which is necessary in a limited number of cases.