Warm Ischemia Time

Laparoscopic donor nephrectomy is associated with longer warm ischemia time when compared to open surgery (39). The warm ischemia time for a typical open surgery should be less than a minute, but this has never been precisely measured in a large series. The University of Maryland six-year experience (10) reported a slow but steady decline in the warm ischemia time for the first 400 cases, showing that the early experience in laparo-scopic donor nephrectomy did require a learning curve for the development of the procedure. At the time of this writing, we reviewed 36 published series comprising 3137 standard transperitoneal laparoscopic donor nephrectomies (Table 1). The average warm ischemia time reported was four minutes for the 2256 cases in which it was measured. The hand-assisted laparoscopic donor nephrectomy technique allows an even quicker extraction after clamping of the renal vessels, as shown in 18 published series reporting a sum total of 744 hand-assisted donor nephrectomies with an average warm ischemia time of only two minutes in the 354 cases in which this parameter was measured.

Despite an average warm ischemia time of only 21/2 minutes for their entire series of 722 donors, the University of Maryland group could not detect a correlation between the length of warm ischemia time and recipient creatinine levels or delayed graft function (10,72).

The impact of small increments in warm ischemia time is largely unknown. In fact, Opelz et al. (73) have shown that there was no strong correlation between warm ischemia time and long-term graft function even in cadaver kidney grafts. In their large series, warm ischemia times even as long as 30 to 40 minutes resulted in no appreciable difference in graft survival (15). At the current time, it is reasonable to assume that any small increase in warm ischemia time results in a small, but probably immeasurable, renal injury.

The etiology of delayed graft function is multifactorial. Table 2 shows that delayed graft function occurred in 3.2% of the 2888 donors reported. Overall, the recipient's serum creatinine at one week following the transplantation was 1.8 mg% (N = 2610), which is comparable to that of open nephrectomy series.

Laparoscopic donor nephrectomy is associated with longer warm ischemia time when compared to open surgery.

Despite an average warm ischemia time of only 21/2 minutes for their entire series of 722 donors, the University of Maryland group could not detect a correlation between the length of warm ischemia time and recipient creatinine levels or delayed graft function.

TABLE2 ■ Laparoscopic Donor Nephrectomy: Recipient Results

Technique

DGF

Creatinine (at 1 wk in mg%)

Ureteral complications

Standard transperitoneal

Maryland (10)

2.6%

2.0

4.5%

UCSF (11-13)

5.0%

1.4

6.0%

Johns Hopkins (14)

2.0%

2.3

6.0%

33 series; n < 125 (15-52)a

3.8%

1.6

2.0%

Subtotal average

3.4%

1.8

4.1%

Hand-assisted

18 series; n < 125 (24,45-63)a

2.8%

1.8

1.1%

Retroperitoneal

Five series; n < 135 (64-68)a

0.6%

1.3

1.5%

Total average

3.2%

1.8

3.7%

aNot all series reported all data points.

Abbreviations: DGF, delayed graft function; UCSF, University of California San Francisco.

Technical modifications included

(i) en-bloc wide removal of the periureteral tissue along with the ureter;

(ii) preservation of the triangle between the junction of the gonadal vein-renal vein and the lower pole of the kidney; and (iii) en-bloc removal of the entire gonadal vein along with the ureter and all periureteric tissue and resulted in lower ureteral complications.

Although the majority of ureteral complications are due to technical errors in harvesting or reimplantation, some distal ureteral strictures can be the result of allograft rejection ischemia.

Since the inception of living, related kidney donation, the better kidney has always remained with the donor.

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