Is the left or right donor kidney preferred for transplantation?

Left Donor Kidney Preferred for Laparoscopic Nephrectomy

The left kidney should be procured in laparoscopic donor nephrectomy unless there are specific anatomical or functional reasons to select the right kidney, primarily because the longer left renal vein (6-10 cm vs. 2-4 cm) provides technical advantages and reduces complications. 1, 2

Primary Recommendation

• In the absence of vascular, urological, or other abnormalities, the left kidney should be procured in laparoscopic donor nephrectomy because of the relative technical ease associated with a longer venous pedicle 1
• The left renal vein's significantly greater length (6-10 cm compared to 2-4 cm for the right) facilitates easier anastomosis during transplantation 2

When to Select the Right Kidney Instead

The right kidney should be chosen when:

• The right kidney is clearly smaller than the left 1
• The right kidney has lower function than the left based on split kidney function studies 1
• The left kidney has anatomical abnormalities such as large cysts 1
• The left kidney has significantly more complicated vascular anatomy (e.g., 3 or more arteries) 1
• The left kidney has venous anomalies such as retroaortic or circumaortic veins, though these are not absolute contraindications 3

Safety Considerations for Right Donor Nephrectomy

Historical Concerns

• Early studies showed increased rates of venous thrombosis with right kidney use due to the very short right renal vein length 1, 2
• The anatomic location of the right kidney increases potential risk of vascular injury to the inferior vena cava and small venous branches 1, 2
• Higher conversion rates to open procedure have been reported when operating on the right kidney 1

Current Evidence on Right-Sided Safety

• With adequate surgeon training and experience, right laparoscopic donor nephrectomy can be performed safely with comparable outcomes to left-sided procedures 1
• A large single-center study of 1,850 laparoscopic donor nephrectomies found that right-sided procedures (n=168) had comparable warm ischemia time, blood loss, hospital stay, and vascular complications to left-sided procedures (n=1,682) 4
• Operating time was actually significantly shorter for right-sided procedures (120 vs. 146 minutes) in experienced hands 4
• A UNOS database analysis of 58,599 living donor transplants found that while right donor nephrectomy had statistically higher rates of delayed graft function (hazard ratio 1.38) and graft thrombosis (hazard ratio 1.48), the absolute differences were extremely small 5

Technical Modifications for Right Donor Nephrectomy

When performing right-sided laparoscopic donor nephrectomy, surgeons should employ:

• Modified stapler port placement such that the right renal vein is transected in a plane parallel to the inferior vena cava 3
• Relocation of the incision for open division of the right renal vein 3
• Lengthening of the donor right renal vein with a panel graft constructed of recipient greater saphenous vein when necessary 3
• Complete mobilization of the left iliac vein with transposition lateral to the iliac artery in the recipient 3

Common Pitfalls to Avoid

• Do not use nontransfixing clips (e.g., Weck Hem-O-lok) to ligate the renal artery in donor nephrectomy; instead, use renal artery transfixation by suture ligature or anchor staple within the vessel wall 1
• Procurement of a living donor kidney with 3 or more arteries should only be undertaken by surgeons with adequate experience 1
• Ensure preoperative spiral CT angiography to better define venous anatomy, particularly for right-sided procedures 3
• Avoid right donor nephrectomy with duplicated right renal veins unless surgeon has extensive experience with technical modifications 3

The "Better Kidney Stays with the Donor" Principle

• The fundamental premise is that the "better" kidney remains with the donor 1
• This principle may override the left-side preference when there are clear functional or anatomical advantages to keeping the left kidney in the donor 1
• Approximately one-fourth of prospective renal donors will have anatomic variations in the renal arteries that dictate choice of the right kidney 6