Partial nephrectomy for patients with a solitary kidney: oncological and functional long term follow up
Introduction: The most critical indication for partial nephrectomy remains a patient with a solitary kidney containing a renal cortical tumour; preserving renal parenchyma is imperative and must be weighed against the risk of compromising oncological efficacy (1). Partial nephrectomy (PN) is still a challenging technique and there have been only a few reports from a limited number of institutions concerning PN for patients with a solitary kidney that provide favourable outcomes for renal function and oncological control (2). Herein, we report long term functional and oncological outcomes in patients who underwent open and laparoscopic PN for RCC in a solitary kidney.
Methods and results
Materials and methods: Medical records of 483 consecutive patients who underwent OPN ( 369 pts) and LPN ( 114 pts) from January 1997 to June 2013 were retrospectively analyzed. Patients presenting with a solitary kidney were identified and their outcomes assessed. A total of 63 patients with a solitary kidney were identified and included in the analysis. Median preoperative radiologic tumour size was 4.1 cm along with a R.E.N.A.L. score of 6. No patient had prior PN of the solitary kidney. 16 patients had an upper pole renal mass, 14 a midpole mass and 33 a lower pole mass. All of the tumors scored below 9 points according to the R.E.N.A.L Nephrometry score.Positive surgical margin was considered when tumor cells were present at the resection margin of the specimen ( presence of tumor tissue on the inked surface of the tumor on final pathologic assessment). Ischemia times (warm and cold) , complication rates , tumour recurrences and renal function outcomes were documented . All patients underwent pre-operative computed tomography. A flank extraperitoneal approach was used for open PN Laparoscopic PN was performed using an intraperitoneal approach for all patients and with a zero-ischemia technique. Renal function was measured by serum creatinine level on postoperative day 1, 3,4,7, 30, 6 and 12 months (3).
Results: The median operative time was 121 min. (121-243).. No remarkable bleeding occurred during surgery. Mean percent of parenchyma resected had been 30±20% . In 36 patients , the pathological examination revealed renal cell carcinoma, in 12 papillary , 8 chromofobe, 7 oncocytoma . Negative surgical margins were achieved in all patients.Post operative stage was characterized by 5 urinary fistulae treated by the placing of uretheral stent, 2 arterovenous fistulae appeared during the 5th and 15th post-operative day which were treated with embolization. 4 patients required blood transfusion due to anemia. Overall, 21% of the patients didn’t experience any increase of serum creatinine, while 41% experienced a significative worsening in serum creatinine values. In 38% of the patients was recorded a not-significant worsening of serum creatinine (4). In 35% of the patients, a worsening of the renal function was recorded, with a increase greater than 50% with respect to the pre-operative values. 70% of these patients had a pre-operative serum creatinine grater than 1.5 mg/dl, a percentage of resected parenchyma of 40% and an average ischemic time > 30 minutes.In the long run follow up, 95,5% of patients preserved a normal renal function, while 5% of patients had the necessity of supportive pharmacological therapy. Our oncologic results in the long run were consistent with what was reported in other studies (5). 22% of patients 14 had a tumor recurrence with a 3.5% of local recurrence, 12% metastases, 6,5% both local and distant masses.8 patients died: 5 for renal tumor, 2 for cardiovascular problems and 1 for unknown cause (6).
Discussion: The persistent nature of multifocal RCC presents a challenging clinical problem. Aggressive surgical interventions must balance adequate cancer control against the risk of end-stage renal failure. While NSS has become the procedure of choice for patients with a surgically naïve solitary kidney, little data exists regarding the feasibility of repeat NSS in a cohort of patients with multifocal RCC and solitary kidney. To our knowledge, only three series have examined the role of repeat NSS.(7,8,9) However, the cohorts in these studies are not exclusively limited to patients with a solitary kidney.
Conclusions: Nephron sparing surgery is an absolute indication in patients with a solitary kidney or renal deterioration. The procedure results safe with low complication rate. After an initial decrease of renal function, it stabilizes in the first post-operative year. The results in the long run show also the validity of the procedure with great oncological results
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