Open Partial Nephrectomy without Ischemia

Background: Vascular clamping during partial nephrectomy could induce to renal ischemia and kidney’s damage due to reperfusion injuries. Adverse effect on renal function can be eliminated by Zero ischemia techniques.The aim of this study was to assess the feasibility of performing partial nephrectomy under a situation of being ready to clamping renal artery. Methods: 24 patients with solitary small renal masses were recruited to the study between 2013and 2018. Open partial nephrectomy was performed for them. During the time corresponding to hilar vessels clamping in standard procedures, we have reached to the renal artery and ready for clamping if needed, and in this situation resection of the mass was assessed. Results The mean age of patients was 42 years. The tumor resection time was 22 minutes averagely. The median procedure time was 92 minutes, Clear cell RCC was found in 19 patients, papillary RCC in 3 and oncocytoma in 2 with no positive surgical cancerous margin in specimens. Lower pole, midzone and upper pole masses were found consequently in14, 2 and 8 cases. Conclusions: Although this technique could be a dangerous decision making in a well exposed renal artery, especially in Polar Regions, the tumor resection can be safely conducted without ischemia.


Background
Although renal masses can be malignant, benign, or inflammatory, the most common malignant renal mass is renal cell carcinoma (RCC), accounting for 2-3% of all kinds of adults' cancers. Historically the gold standard treatment for RCC was radical nephrectomy (RN), but recent studies suggested that partial nephrectomy (PN); in compared to radical nephrectomy (RN), may be associated with improved survival for small renal tumors (between 4 centimeters (cm) or less and 7 cm or less), and has the benefit of preserving renal function (1). Although RN is a known risk factor of chronic kidney disease (CKD) in patients with renal tumors, it is still the most common procedure which is performed in patients with small renal tumors (2). PN mostly used for patients who would be rendered anephric after radical nephrectomy, for example patients with bilateral RCC and single kidney patients with RCC were subjects of PN and the fear of positive surgical margins leading to increase the risk of local recurrence, limited the widespread use of PN. The significant improvement in imaging techniques has led to increased detection of small renal tumors and caused PN to be used for this small renal tumors (3). Application of Vascular clamp during PN can lead to renal ischemia and the consequences that are called reperfusion injuries. Adverse impact on renal function (RF) can be eliminated by Zero Page 3/12 ischemia techniques. We plan to assess the possibility of performing PN under a situation of being ready to clamping renal artery.

Methods
During a retrospective study, 24 patients with solitary small renal masses were recruited to the study between 2013and 2018. Open partial nephrectomy was performed for them.
During the time corresponding to hilar vessels clamping in standard procedures, we have reached to the renal artery and ready for clamping if needed, and in this situation resection of the mass was assessed. All patients underwent the procedure with 1 to 2 centimeters of free margins. All of the patients were evaluated by abdominal spiral CT Scan without and with intravenous Contrast for defining the exact size and location of the renal masses.

Results
The mean (SD) age of patients was 41.96   Regarding better preservation of renal function in OPN, in comparison to RN, this technique seems to have a major benefit. LPN seems to be associated with a longer ischemia time, a higher re-operative rate, and also increased complication rates. Currently, surgeons have main concerns over preservation of renal function in any operative techniques with continued efforts toward decreasing warm ischemia without compromising the oncological efficacy (21). In our study we have omitted any type of ischemia in setting of exposed renal artery, ready for clamping and this means lower risk of ischemia in preserved, functioning and healthy renal tissue.
Funahashi Y. and coworkers compared warm and cold ischemia on renal function after PN and reported that warm ischemia for more than 25 minutes caused widespread injuries to the operated kidney, whereas cold ischemia for less than 58 minutes prevented ischemic injury to the preserved part of the kidney (22). We didn't use any type of ischemia, as a result, no ischemia induced complication could be considered.
In a study conducted by Jiwei Huang and coworkers found that in comparison to conventional LPN, by considering the safety and efficacy of laparoscopic radio frequency ablation (LRFA) during a prospective randomized controlled trial, LRFA assisted tumor enucleation with no ischemia, enables tumor excision with better renal function preservation (23). This clinical trial confirms the feasibility and safety of our study.
Partial nephrectomy is an accepted procedure for small renal malignant tumors both in high and low volume centers. There are many options for performing this procedure according to preference of the surgeon, situation of the patient, and availability of surgical equipment. In our technique of surgery, we have omitted any type of ischemia in setting of exposed renal artery and showed that this technique may be feasible and cost effective. We suggest more studies with higher number of patients to support the results of this study.
Partial nephrectomy is an accepted procedure for small renal malignant tumors, but there are many options for performing this procedure according to preference of the surgeon, situation of the patient, and availability of surgical equipment, ablative procedures, open, laparoscopic, and robotic surgery may be selected. Current management of renal tumors focuses on nephron sparing techniques due to equivalent oncogenic results while potentially decreasing renal and cardiovascular morbidity compared to radical nephrectomy. Every type of ischemia may have the potential of developing short-and long-term renal function decline after partial nephrectomy, but in our technique of surgery we have omitted any type of ischemia in setting of exposed renal artery, ready for clamping and this means lower risk of ischemia in preserved, functioning and healthy renal tissue. On the other hand, in our study OPN is a significant cost-effective procedure with no need for expensive equipment.

Competing interests
The authors declare no competing interests.
Compliance with Ethical Standards (Ethical approval and Consent to participants): All procedures performed in this study were in accordance with the ethical standards of the All authors listed have contributed sufficiently to the project to be included as authors, and all named authors have seen and approved the final version of the manuscript.

Funding
None declared

Data Availability
The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request. All data about the participants are gathered in a table, and are available on request.