Long-Term Functional Outcome of Renal Units after Laparoscopic Nephron-Sparing Surgery under Cold Ischemia

Comparison of Intermittent Versus Continuous Ischemia During Laparoscopic Partial Nephrectomy in a Porcine Model

Renal ischemic time is one of the most variable risk factors in partial nephrectomy (PN). Our purpose was to investigate if intermittent ischemia could decrease renal impairment in the process of PN in porcine model and explore the feasibility of this surgical procedure in nephrectomy. A kidney ischemia-reperfusion injury model was successfully established in six pigs under laparoscopic surgery. One kidney of each pig was continuously ischemic, and intermittent ischemia was administered to the kidney of another side. Laparoscopic renal artery occlusion was applied to each kidney for 120 minutes. Intermittent ischemia was 15/3 minutes of cycles (ischemia for 15 minutes and reperfusion for 3 minutes). Microdialysis technique, immunohistochemistry, and histopathology were used to evaluate the extent of renal function injures. The concentration of glycerol in intermittently ischemic group was significantly lower than that in continuously ischemic group (F = 19.06, p = 0.001). NGAL and BCL-2 immunostaining of the renal tubular epithelial cell in the intermittent ischemia kidneys was significantly reduced compared with that in the continuously ischemic kidneys (F = 5.51, p = 0.041; F = 13.53, p = 0.004). Our study has shown that intermittent ischemia is a possibly effective and practicable surgical process for reducing renal ischemic damage in porcine model nephrectomy.

Zero ischaemia laparoscopic nephron-sparing surgery by re-suturing

AIM OF THE STUDY

To report a pre-suture technique in laparoscopic nephron-sparing surgery (LNSS), which could help reduce and even avoid ischaemia for the treatment of renal cell carcinoma.

MATERIAL AND METHODS

Between January and June 2013 we treated 14 patients presenting with renal tumours. The mean age was 46 years and average tumour size was 2.4 cm in diameter determined by computed tomography (CT). All the patients were treated with LNSS by pre-suturing the resection.

RESULTS

In 13 out of the 14 cases, no clamping was needed during the whole surgery processes, i.e. zero ischaemia was achieved. In the other case, the renal artery was clamped for only 150 seconds due to suture avulsion. The mean operating time was 75 minutes (range 50 to 110 minutes) and mean blood loss was 60 ml (range 30 to 200 ml). After removal of the drain 2-3 days after surgery, the average postoperative hospital stay time was four days. The surgery had only a minor effect on the renal function. No case of urinary leakage or postoperative bleeding occurred. Postoperative pathological reports showed that the tumours were resected completely with negative surgical margins for all cases. There were no signs of recurrence on follow-up CT performed 1-6 months after surgery.

CONCLUSIONS

The pre-suture technique in LNSS reported here required zero or minimal ischaemia time and hence avoided renal ischaemia-reperfusion injury. This surgical technique could be a feasible surgical option for treatment of small, exophytic and peripheral renal tutors.

Laparoscopic Partial Nephrectomy Using FloSeal for Hemostasis: Technique and Experiences in 102 Patients

Objectives. The authors report their techniques, perioperative data, and oncological outcome for laparoscopic partial nephrectomy in a single-center experience with 3 different surgeons. Patients and methods. A total of 102 consecutive patients underwent laparoscopic transperitoneal partial nephrectomy for exophytic tumors using FloSeal for hemostasis. Mean age was 58 years (range = 26-79 years), and median tumor size was 2.6 cm (range = 0.5-8.5 cm). In 84 cases, the renal artery was clamped using endoscopic bulldog clamps, and tumor resection was performed using scissors or the harmonic scalpel. Hemostasis was achieved by application of FloSeal; lesions of the collecting system were closed with Lahodny sutures in 33 cases (31%). Frozen sections were obtained for margin status. Results . All 102 procedures were successful with no intraoperative complications. Mean surgical time was 201 minutes (range = 60-355 minutes); clamping time was 25.8 minutes (range = 6-75 minutes) in 64 cases. Margins were negative in 92 cases; in 8 cases secondary resection was necessary to achieve negative margin status, and in 2 cases radical nephrectomy was performed. Histological findings were clear-cell carcinoma in 51 (50.0%), papillary carcinoma in 26 (25.5%), and others in 25 (24.5%) cases. At a mean follow-up of 32 months (12-62 months), no recurrence was observed. Conclusions. Laparoscopic partial nephrectomy with the use of FloSeal is a feasible and safe method for treatment of small renal masses. The technique is reproducible by surgeons who are used to complex laparoscopic procedures. Patient outcome during follow-up was comparable with data published for open standard procedures.

Assessing the impact of ischaemia time during partial nephrectomy

CONTEXT

The impact of applying renal ischaemia during nephron-sparing surgery to avoid renal damage in the treated kidney has gained importance in different surgical techniques.

OBJECTIVE

The main objective of the present study is to point out the limit of renal ischaemia times for warm and cold ischaemia approaches. Important results of research on renal ischaemia and different surgical techniques as well as results of clinical studies concerning renal function after renal ischaemia in partial nephrectomy are highlighted.

EVIDENCE ACQUISITION

A Medline literature research was performed, combining queries on the keywords nephron-sparing surgery, partial nephrectomy, and ischemia. Links to related articles and cross-reading of citations in related articles were surveyed, as were reviews, letters to editors, and information collected from urologic textbooks. The references formed the basis of this review article, with selection and deletion based on the relevance and importance of the content. In a final step, interactive peer review by the expert panel of coauthors completed the review.

EVIDENCE SYNTHESIS

Renal ischaemia research showed an increasing renal damage proportional to ischemic time. Current clinical data support safe ischaemia times, within 20 min of warm ischaemia and up to 2 h of cold ischaemia, to minimise renal ischemic damage. To date, no ischaemia dose-response curve or algorithm is available to predict the risk of acute kidney injury and chronic kidney disease in patients undergoing intraoperative ischaemia. In general, there seems to be a higher risk for comorbidity caused by renal damage in patients suffering from kidney tumour.

CONCLUSIONS

If ischaemia is required, the tumour should be removed within 20 min of warm ischaemia, regardless of surgical approach. Efforts should be made to start immediately with cold ischaemia, if the feasibility within this span of time seems to be jeopardised. Thus, cold ischaemia times up to 2 h can be tolerated by the kidney, depending on the individual method. Nevertheless, cold ischaemia with ice slush should be kept as short as possible--at best within 35 min. In ischemic nephron-sparing surgery, one of the surgeon's main aims should be to avoid loss of renal function. Only after optimal preoperative appraisal and planning can the best postoperative outcomes for renal function be achieved.

Haemostasis in laparoscopic partial nephrectomy: Current status

Laparoscopic partial nephrectomy (LPN) is increasingly performed all over the world. However, as in its open counterpart, achieving a satisfactory haemostasis may be challenging. Our goal is to describe the different methods employed to control bleeding during LPN. We performed a non-structured review of the literature on the different haemostatic methods used during LPN. The techniques and materials used are divided into two main groups: LPN with ischemia and LPN without ischemia. The techniques to achieve warm, cold and regional ischemia are described. Energy sources and sealants are discussed in the section on LPN without ischemia. Case selection is of capital importance in the choice the appropriate haemostatic tools for LPN. Some refinements, related to the nature of the laparoscopic procedure, are still required to reach an effective cold ischemia. A broad variety of energy sources have been tested in animal models and in human setting. Major disadvantages are tissue scarring, smoke creation and low progression speed. To date none has been demonstrated to be superior to the conventional suturing. Fibrin and thrombin promoters as bio-glues are an important adjuvant method during LPN. Bipolar current devices together with fibrin sealants or coagulation promoters are used in small peripheral tumors. In bigger or central tumors, additionally suturing over Surgicel bolsters, the most popular technique is to secure the suture by means of clips. The level of the recommendations is based on comparative cohorts. We conclude that haemostasis is achieved during LPN adapting the protocols used in open nephron sparing surgery to the laparoscopic approach. Renal ischemia and bolster sutures are still mandatory in complicated LPN while in case of small exophytic tumors a satisfactory haemostasis may be achieved by using only a sealant product.

Importance and limits of ischemia in renal partial surgery: experimental and clinical research

Introduction. The objective is to determine the clinical and experimental evidences of the renal responses to warm and cold ischemia, kidney tolerability, and available practical techniques of protecting the kidney during nephron-sparing surgery. Materials and methods. Review of the English and non-English literature using MEDLINE, MD Consult, and urology textbooks. Results and discussion. There are three main mechanisms of ischemic renal injury, including persistent vasoconstriction with an abnormal endothelial cell compensatory response, tubular obstruction with backflow of urine, and reperfusion injury. Controversy persists on the maximal kidney tolerability to warm ischemia (WI), which can be influenced by surgical technique, patient age, presence of collateral vascularization, indemnity of the arterial bed, and so forth. Conclusions. When WI time is expected to exceed from 20 to 30 minutes, especially in patients whose baseline medical characteristics put them at potentially higher, though unproven, risks of ischemic damage, local renal hypothermia should be used.

Laparoscopic versus open partial nephrectomy: analysis of the current literature

OBJECTIVES

To critically review the current scientific evidence about open partial nephrectomy (OPN) and laparoscopic partial nephrectomy (LPN) to define the current role of these techniques in the treatment of renal tumours.

METHODS

PubMed and Medline were searched for reports about OPN and LPN that were published from 1990 to 2007 and the most relevant papers were reviewed.

RESULTS

OPN is an established curative approach for the treatment of small renal tumours. LPN is challenging and the technique is still under development. The intermediate-term oncologic and functional outcomes of LPN are similar to those of OPN in experienced centres. However, the ischaemia time is longer in laparoscopy and a long learning curve is needed to decrease the risk of complications. In the first phase of a surgeon's experience with LPN, a careful case selection based on the tumour growth pattern is required.

CONCLUSION

OPN is today the first treatment option for small renal tumours. LPN is technically challenging, but has been shown to achieve similar intermediate-term cancer cure and renal function results in centres with advanced laparoscopic expertise. Larger series with longer follow-up and prospective randomised studies are needed to confirm the safety and efficacy of LPN.

Laparoscopic partial nephrectomy: how far have we gone?

PURPOSE OF REVIEW

Several technical modifications of laparoscopic partial nephrectomy have resulted in a reduction of complications and warm ischemia time. The most recent results are reviewed with a focus on oncologic outcome and postoperative renal function.

RECENT FINDINGS

The indications for laparoscopic partial nephrectomy are the same as for open surgery. All tumors up to 4 cm should be included and selected tumors up to 7 cm may be considered as well. In experienced hands, the complication rate is considerably low. Oncologic outcome is comparable with open partial nephrectomy and 5-year survival data have been published recently. Long warm ischemia time may be of some concern. The published functional results are excellent. Cost should not be the main argument in favor of a method. Laparoscopic partial nephrectomy, however, combines advantages for the patient with lower cost as shown by two studies.

SUMMARY

Laparoscopic partial nephrectomy duplicates the principles of open surgery and has been standardized to a great extent. It is technically difficult and is being performed by a small number of centers only; however, the interest of the urologists and patient demand is growing quickly. At the present time, laparoscopic partial nephrectomy cannot be considered a standard of care, but excellent results have been reported when performed by experienced laparoscopists.

Laparoscopic Partial Nephrectomy with Clamping of the Renal Parenchyma: Initial Experience

OBJECTIVES

Partial nephrectomy by laparoscopy offers patients conservative surgery and a mini-invasive approach; however, clamping of the renal pedicle and the induced warm ischaemia can damage the renal parenchyma. We present a technique of laparoscopic partial nephrectomy with haemostasis obtained by clamping of the renal parenchyma.

METHODS

The procedure was performed by an intraperitoneal or a retroperitoneal approach. After a working space is created by pneumodissection, Gerota's fascia is incised and the kidney convexity is dissected. An endoscopic Satinsky clamp is inserted percutaneously through a 1-cm incision. The renal parenchyma is clamped and the tumour is excised in a bloodless field. The cut renal parenchyma is coated with biologic glue.

RESULTS

Five patients with elective indications were operated. Mean age was 67.8 yr and mean tumour diameter 3.06 cm. One lesion was located at the upper pole and four at the lower pole. Mean preoperative serum creatinine level was 10.9 mg/l. Postoperative serum creatinine level was unchanged. Mean operative time was 238 min. There was no conversion. Mean blood loss was 250 ml; no transfusions were necessary. The collecting duct system was repaired in one patient. No complication was noticed. Resection margins were tumour free in all cases. Final pathologic examination revealed clear cell carcinoma in three cases and angiomyolipoma and oncocytoma in one case each.

CONCLUSION

Laparoscopic partial nephrectomy with clamping of the renal parenchyma can be performed in selected patients with peripherally placed tumours. The procedure avoids warm ischaemia of the normal parenchyma while allowing the surgeon to operate in an almost bloodless field. This initial experience in five patients should be validated in a larger series.

Laparoskopische oder offene Tumornephrektomie und Nierenteilresektion

After initial scepticism laparoscopic radical nephrectomy has rapidly been developed to a standard of care which should be offered to all patients as an alternative to open surgery. This procedure is indicated for all renal tumours clinical stage 1-2 which are not considered for partial nephrectomy. Many studies now show that the oncologic outcome is good and comparable to open surgery. Follow-up, however, is limited to about 10 years. Laparoscopic radical nephrectomy has become a standardized procedure. Removal of the kidney by morcellation, favoured by the majority some time ago, has been abandoned to a great extent. Also the controversy about the advantages and disadvantages of the respective approach has been settled. Several prospective randomized studies proved that both the transperitoneal and retroperitoneal approaches are equally effective. Excluding the bias of the learning curve the complication rate of laparoscopy is not higher than that of open surgery, but morbidity is clearly lower. Since the rate of elective partial nephrectomy is increasing rapidly, laparoscopy may be a good choice for this indication as well. When performed during ischaemia all principles of open surgery--excision of the tumour with clear margins, haemostasis using sutures, closure of the collecting system, suture repair of the renal parenchyma--can be duplicated. The problem of long warm ischaemia time can be managed by the evolution of the surgical technique, but also by induction of hypothermia. Complication rates are comparable to open surgery. Oncologic results, with limited follow-up however, are promising.