To compare safety and efficacy between open and robotic partial nephrectomy in treatment of organ confined complex renal tumors (R.E.N.A.L score more than 7) as regarding surgical results, morbidity, clinical as well as oncological and functional outcomes.

Although radical nephrectomy was considered as the only effective treatment for malignant kidney tumors and maintained the prime solution for such tumors throughout the nineteenth century, partial nephrectomy became the preferred method in managing tumors of solitary kidneys, bilateral or hereditary renal tumors and in renal tumors of renal insufficiency patients. The shift to preserve sufficient as well as functioning renal volume, the improving experience with renal vasculature, proliferation of energy sources that achieved sufficient tissue cleavage and haemostatic power and refinements in hypothermia techniques helped the shift towards nephron sparing surgeries. Partial nephrectomy aimed at achieving complete removal of renal tumor with preservation of renal function, minimizing ischemia time as well as operative complications.

Open partial nephrectomy was the standard management strategy for organ-confined renal tumors in many centers worldwide. It is still the preferred method in most situations of complex tumors. Yet, open surgery has the inherent problem of poorly cosmetic scar, the need for analgesics, long hospital stay and wound related complications.

Laparoscopic partial nephrectomy (LPN) has largely replaced open partial nephrectomy worldwide as it combines the benefits of nephron sparing surgery (preserving the renal function) and laparoscopy (decreasing morbidity). The increasing experience of LPN enabled surgeons to operate not only small, peripheral, exophytic renal tumors, but also larger infiltrating tumors have been managed similarly. On the other hand, LPN still has technical difficulties that need steep learning curve to be mastered.

Robotic partial nephrectomy has become the surgery of choice not only for most renal tumors but also for benign kidney lesions. The minimally invasive nature of robotic surgery offers numerous advantages to the patient over open surgery including minimal tissue trauma, smaller scars, and faster recovery. Unlike laparoscopy, robotic surgeries grantee a three-dimensional view. The complex operative steps can be easily done due to the wider range of motion of the surgical instruments that the robot provides. Moreover, recent studies showed that robotic partial nephrectomy has shorter ischemia time, less blood loss and faster recovery than laparoscopy.

Despite the multiplicity of studies done for comparing between open and robotic partial nephrectomy in cases of small renal tumors, there are fewer studies comparing between open and robotic partial nephrectomy in management of complex renal tumors, which are not based on randomized bases.

Assiut University Hospitals are intending to be in a leading position in the field of minimal invasive surgery by constructing the first robotic surgery center in Upper Egypt. So, in our study, although robotic surgery seems to be more expensive, investigators suppose that robotic partial nephrectomy will yield better surgical and functional results than open partial nephrectomy in managing complex renal tumors. The promising technology will lead to decrease the robotic industry cost which, till now, remains the major drawback of robotic surgery worldwide spread. Another priority of our intended study is that it will alleviate any selection bias between the two techniques by being a prospective randomized one.

Inclusion Criteria:

• Any patient aged more than 18 years old with high complex renal tumor according to R.E.N.A.L scoring system (R.E.N.A.L score more than 7).

Exclusion Criteria:

• 1- Renal tumors with R.E.N.A.L score less than 7, based on radio-logical findings.

  2- Renal tumors in congenitally anomalous kidney (horseshoe kidney, ectopic or malformed) or metastatic kidney disease.

  3- Gross lymphadenopathy (N1 According to TNM classification system of renal tumors) or suspicious vascular invasion (T3a, T3b or T3c according to TNM classification of renal tumors) (18).

  4- Renal pelvic tumor of upper urinary tract. 5- Patient refused to be enrolled in the study. 6- Defaulters of follow up. 7- Bleeding tendency. 8- Active peritoneal or bowel inflammatory process. 9- Clinically unfit patient.