Laparoscopic Partial Nephrectomy in Patients with Compromised Renal Function

Renal Ischemia and Function After Partial Nephrectomy: A Collaborative Review of the Literature

CONTEXT

Partial nephrectomy (PN) is the current gold standard treatment for small localized renal tumors.; however, the impact of duration and type of intraoperative ischemia on renal function (RF) after PN is a subject of significant debate.

OBJECTIVE

To review the current evidence on the relationship of intraoperative ischemia and RF after PN.

EVIDENCE ACQUISITION

A review of English-language publications on renal ischemia and RF after PN was performed from 2005 to 2014 using the Medline, Embase, and Web of Science databases. Ninety-one articles were selected with the consensus of all authors and analyzed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.

EVIDENCE SYNTHESIS

The vast majority of reviewed studies were retrospective, nonrandomized observations. Based on the current literature, RF recovery after PN is strongly associated with preoperative RF and the amount of healthy kidney parenchyma preserved. Warm ischemia time (WIT) is modifiable and prolonged warm ischemia is significantly associated with adverse postoperative RF. Available data suggest a benefit of keeping WIT <25min, although the level of evidence to support this threshold is limited. Cold ischemia safely facilitates longer durations of ischemia. Surgical techniques that minimize or avoid global ischemia may be associated with improved RF outcomes.

CONCLUSIONS

Although RF recovery after PN is strongly associated with quality and quantity of preserved kidney, efforts should be made to limit prolonged WIT. Cold ischemia should be preferred when longer ischemia is expected, especially in presence of imperative indications for PN. Additional research with higher levels of evidence is needed to clarify the optimal use of renal ischemia during PN.

PATIENT SUMMARY

In this review of the literature, we looked at predictors of renal function after surgical resection of renal tumors. There is a strong association between the quality and quantity of renal tissue that is preserved after surgery and long-term renal function. The time of interruption of renal blood flow during surgery is an important, modifiable predictor of postoperative renal function.

Laparoscopic partial nephrectomy for >4 cm renal masses

INTRODUCTION

Laparoscopic partial nephrectomy (LPN) is frequently used to manage cT1a renal masses. While data on safety and long-term oncological outcomes of LPN for T1a tumours are widely available, it is limited for >T1a lesions. We report our experience with LPN for >4 cm renal masses from a Canadian tertiary centre.

METHODS

Between January 2003 and July 2011, 52 consecutive LPN for >4 cm renal masses were performed. Demographic, pathological and clinical data were obtained from a prospectively maintained database.

RESULTS

The mean patient age was 60 years (62% male). Median tumour size was 4.8 (range: 4.2-11) cm. The median surgical time was 145 minutes, and the median estimated blood loss was 100 mL. The median warm ischemia time was 24 minutes. Four (7.7%) cases required conversion to open surgery. One case was converted to total nephrectomy for clinical and pathological evidence of T3 disease. The surgical margin was positive in 1 case (1.9%). Four (7.7%) patients developed a urine leak postoperatively; 3 of them managed with a ureteric stent. Four (7.7%) patients developed postoperative bleeding requiring selective angioembolization. The median hospital stay was 4 days. There was no statistically significant difference between preoperative and postoperative estimated glomerular filtration rate and mean arterial blood pressure (p = 0.5, p = 0.1, respectively).

CONCLUSION

This series demonstrates that LPN although technically challenging has acceptable short-term surgical outcomes. Long-term assessment of oncological outcomes is required. Laparoscopic partial nephrectomy >4 cm renal tumours should not be considered a standard of care, but excellent results can be achieved in well-selected patients and in experienced hands with no impact in renal function or blood pressure.

Comparison of the loss of renal function after cold ischemia open partial nephrectomy, warm ischemia laparoscopic partial nephrectomy and laparoscopic partial nephrectomy using microwave coagulation

PURPOSE

Nephron sparing surgery is an effective surgical option in patients with renal cell carcinoma. Laparoscopic partial nephrectomy involves clamping and unclamping techniques of the renal vasculature. This study compared the postoperative renal function of partial nephrectomy using an estimation of the glomerular filtration rate (eGFR) for a Japanese population in 3 procedures; open partial nephrectomy in cold ischemia (OPN), laparoscopic partial nephrectomy in warm ischemia (LPN), and microwave coagulation using laparoscopic partial nephrectomy without ischemia (MLPN).

MATERIALS AND METHODS

A total of 57 patients underwent partial nephrectomy in Yokohama City University Hospital from July 2002 to July 2008. 18 of these patients underwent OPN, 17 patients received MLPN, and 22 patients had LPN. The renal function evaluation included eGFR, as recommended by The Japanese Society of Nephrology.

RESULTS

There was no significant difference between the 3 groups in the reduction of eGFR. eGFR loss in the OPN group was significantly higher in patients that experienced over 20 minutes of ischemia time. eGFR loss in LPN group was significantly higher in patients that experienced over 30 minutes of ischemia time.

CONCLUSION

This study showed that all 3 procedures for small renal tumor resection were safe and effective for preserving postoperative renal function.

Phosphodiesterase 5 inhibition protects against increased intra-abdominal pressure-induced renal dysfunction in experimental congestive heart failure

AIMS

Congestive heart failure (CHF) is associated with impaired renal function. Previously, we have demonstrated that rats with decompensated CHF exhibited exaggerated sensitivity to the adverse renal effects of increased increased intra-abdominal pressure (IAP) as compared with normal controls. This study tested whether phosphodiesterase 5 (PDE5) inhibition protects against the adverse renal effects of increased IAP in rats with CHF.

METHODS AND RESULTS

Following baseline periods, rats with compensated and decompensated CHF induced by the placement of an aorto-caval fistula (ACF), rats with myocardial infarction (MI) induced by left anterior descending (LAD) artery ligation, and sham controls were subjected to consecutive IAPs: 7, 10, or 14 mmHg. Urine flow (V), Na(+) excretion (U(Na)V), glomerular filtration rate (GFR), and renal plasma flow (RPF) were determined. The effects of pre-treatment with tadalafil on the adverse renal effects of IAP were examined in rats with decompensated CHF and MI. Elevation of IAP to 10 and 14 mmHg produced linear reductions in these parameters. Basal renal function and haemodynamics were lower in CHF rats. Decompensated CHF rats and MI rats that were subjected to 10 and 14 mmHg exhibited exaggerated declines in V, U(Na)V, GFR, and RPF. In contrast, no adverse renal effects were observed in rats with compensated CHF subjected to IAP. Pre-treatment of decompensated CHF rats and MI rats with tadalafil ameliorated the adverse renal effects of high IAP.

CONCLUSION

Decompensated CHF and MI rats are vulnerable to the adverse renal effects of IAP. Tadalafil abolishes IAP-induced renal dysfunction, supporting a therapeutic role for PDE5 inhibition in CHF associated with ascites.

Postoperative renal function after partial nephrectomy for renal cell carcinoma in patients with pre-existing chronic kidney disease: a comparison with radical nephrectomy

We assessed whether adequately functioning parenchyma is preserved in patients with pre-existing chronic kidney disease (CKD) after partial nephrectomy (PN) compared with those who underwent radical nephrectomy (RN). A total of 95 patients with pre-existing CKD who underwent curative surgery for pathological T1a-T2N0M0 renal cell carcinoma with a follow-up period of 12 months or more were the subject of the present study. Of these, 51 patients underwent RN, and 44 PN. Renal function was assessed by using the estimated glomerular filtration rate (e-GFR). We classified the subjects into two groups according to the preoperative e-GFR: preoperative e-GFR 45-59 mL/min/1.73 m(2) (68 patients); and 30-44 mL/min/1.73 m(2) (27 patients). In the former group, the probability of freedom from new onset of e-GFR <45 mL/min/1.73 m(2) stemmed from the significant difference between the PN and RN groups (P = 0.006; PN: 2 years 64%; RN: 2 years 22%). In contrast, in the latter group, the probability of freedom from new onset of e-GFR <30 mL/min/1.73 m(2) was not associated with a significant difference between PN and RN group (P = 0.80). Overall survival and the number of the patients who went on to develop end-stage renal disease requiring renal replacement therapy between PN and RN were not significantly different in each group. Death from renal cell carcinoma was not noted in either group. PN could significantly prevent development to late-stage CKD in patients with preoperative e-GFR 45-59 mL/min/1.73 m(2) compared with RN. Patients with preoperative e-GFR 30-44 mL/min/1.73 m(2) should be reviewed in a more strict study.

Laparoscopic partial nephrectomy: advances since 2005

PURPOSE OF REVIEW

Laparoscopic partial nephrectomy (LPN) technique has continually evolved over the last decade, resulting in better outcomes and increased popularity within the urological community. In this article, we provide an overview of the contemporary literature on LPN.

RECENT FINDINGS

The technique of LPN has evolved over the last 5 years with a nearly 50% reduction of warm ischemia time in experienced hands. Complication rates have also declined such that morbidity and oncological outcomes are comparable to open partial nephrectomy, the gold standard. LPN is now an established procedure for the treatment of T1a renal tumors. It can also be safely performed for favorably located T1b tumors and more complex tumors, including hilar tumors, central tumors or tumors in solitary kidneys with good oncological and functional outcomes.

SUMMARY

For renal tumors less than 4-7 cm (T1 lesions), partial nephrectomy is the treatment of choice. Contemporary LPN is a sophisticated procedure, and in expert hands, offers perioperative, functional and oncologic outcomes comparable to open partial nephrectomy, even for complex tumors.

Magnetic resonance nephrourographic techniques and applications: how we do it

Chronic kidney disease is a significant public health problem, and a comprehensive evaluation of renal disease often requires accurate evaluation of both kidney structure and function. Magnetic resonance (MR) nephrourography refers to newly developed imaging techniques that have the ability to provide a quantitative assessment of renal function, especially glomerular filtration rate and renal blood flow. Our review outlines several different methodologies that are present in the literature and also details the specifics of our own methods for renal imaging. Though varied, all MR imaging methods use the common steps of image acquisition, image postprocessing, and tracer kinetics modeling of the processed image data. The optimal methodology should be practical and based primarily on simplicity, speed, and reproducibility. The combination of anatomic and quantitative functional information of the kidneys provided by MR imaging allows for a safe, comprehensive evaluation of renal disease, with particular utility in the settings of urinary tract obstruction and renal transplantation.