Table 1. Surgical comparison of trans and retro approach to PN.

Surgical steps	Transperitoneal			Retroperitoneal
	Left	Right		Left	Right
Port positioning	Figure 1			Figures 2,3
Position of surgical robot	Posterior to patient’s back			Cranial to patient
Approach to kidney/renal hilum	Transperitoneal approach with identification of transperitoneal landmarks/intrabdominal viscera			Retroperitoneal approach with identification of psoas muscle
	Mobilization of colon, splenorenal ligament, spleen and pancreatic tail	Mobilization of colon, duodenum, IVC fascia		Identification of artery anterior to periaortic lymph nodes. Care must be taken to avoid dissection posterior to aorta	Identification of renal artery posterior to vena cava
	Identification of adrenal/gonadal vein	Identification of adrenal vein
Identification of renal tumor	Identify tumor location based on pre-operative imaging
	Peri-renal adipose tissue is removed to expose the kidney parenchyma
	May utilize intraoperative imaging techniques (i.e., ultrasound)
	Electrocautery is used to delineate borders for tumor excision
Arterial clamping (if necessary)	Application of bulldog clamp for selective or complete renal arterial ischemia
Tumor resection vs. enucleation	Tumor is removed using resection, enucleation, or combination of both
Renorrhaphy	Resection bed is secured with absorbable suture. Open vascular channels at the tumor base are oversewn
	Horizontal mattress renorrhaphy is completed with 2-0 barbed suture, applying surgical clips for appropriate tension on the parenchyma
	If dead space is created during renorrhaphy closure, hemostatic agent bolsters may be placed prior to tightening the suture to facilitate hemostasis (23)

PN, partial nephrectomy; IVC, inferior vena cava.