In patients with renal cell carcinoma (RCC), a partial nephrectomy (PN) provides an equivalent oncological outcome and better preservation of renal function than a radical nephrectomy in properly selected patients. As part of the ongoing trend towards minimally invasive surgery (MIS), laparoscopic or robotic PN, or both, are becoming common worldwide, though these procedures are still associated with several negative issues that should be avoided or reduced, including CO2 gas insufflation, ischemia of the kidney, multiple-site access, the transperitoneal approach and high cost of the equipment.

CO2 gas insufflation is associated with risks of cardiovascular and respiratory dysfunction, although these risks very rarely result in significant clinical problems.1 However, considering the rapid aging of population that is occurring across the world, these risks for aged patients should be taken into greater consideration. The retroperitoneal approach, which reduces the risk of delay in resuming oral feeding and intestinal adhesion, is particularly beneficial for aged patients. In order to preserve postoperative renal function, which may be associated with patient survival,2 various techniques including minimization of clamping time3 or ischemic area4 have been developed. Overall, if it is possible, a PN without clamping is ideal. Single site surgery, which typically results in a minimal postoperative scar, has also been tried in both laparoscopic and robotic surgery. As far as equipment cost is concerned, any reduction in the cost of the expensive disposable devices used through the trocar ports or the robotic system would be welcomed.

An MIS technique that meets all the above requirements while preserving cancer control would be most beneficial for patients. Our own attempts to establish one, which have been taking place since 1998, have led to the development of the GasLESS technique called minimum incision endoscopic surgery, which can be used for almost all urological organs.5–10 Our most recent series consists of GasLESS-clampless PN procedures performed on 104 patients in whom peripheral renal tumors were evaluated.

These operations were performed by 18 surgeons without gas insufflation, via a single port, without clamping and using the retroperitoneal approach. The technique itself has been presented previously.8 In brief, the normal tissue adjacent to the tumor is transected using an ultrasonic coagulator under ultrasound guiding. At most the movability of the kidney is used to perform this procedure. The median tumor size and preoperative aspects and dimensions used for an anatomical score were 2.0 cm (range, 1–8) and 7 (range, 6–9), respectively. The median operative time and blood loss were 189 min and 168 mL, respectively. Two patients received blood transfusion. Although the size of each single port (range, 3.5–8 cm) depended on the tumor size and location, especially in recent years the size presented in Figure 1 has become a standard for many cases. The median postoperative days to resume oral feeding and to walk more than 100 m were 1 and 2 days, respectively. The surgical margin positive rate was 10% of the total and 3% of 36 recent PN in which microwave tissue coagulation (MTC) was omitted. Most of the positive margin sites consisted of microscopic evidence of thermal degeneration by MTC. During the follow-up period (mean, 33 months), no local recurrence has been observed except in one case, in which a patient with bilateral RCC underwent MTC for suspected local recurrence. The major complication rate was 3%, urinary leakages requiring radiological intervention under local anesthesia. The median percentage change in estimated glomerular filtration rate at 3 months after PN was −3.6%.


Figure 1. GasLESS-clampless partial nephrectomy showing (a) single port (major axis 3.8 cm and minor axis 2.4 cm) and resected specimen and (b) a cross-section of the specimen presented in (a): a; perinephric fat, b; tumor, c; normal renal parenchyma.

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For non-peripheral (central or hilar) cases, promising results have been obtained.

Minimally invasive PN performed using a gasless, single port access and a clampless retroperitoneal approach seems to be a safe and technically feasible form of MIS with acceptable pathological and renal function outcomes, and therefore deserves further investigation.

Conflict of interest

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None declared.


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  2. Conflict of interest
  3. References