Warm Ischemia Worsens Partial Nephrectomy Outcomes, Study Finds
Warm ischemia during partial nephrectomy (PN) on a solitary kidney is associated with an increased risk of acute renal failure (ARF) and CKD, according to researchers.
Consequently, they concluded, “PN with no ischemia should be used when technically feasible in patients with solitary kidney.”
R. Houston Thompson, MD, of Mayo Clinic in Rochester, Minn., and collaborators studied 458 patients who underwent open PN (411 patients) or laparoscopic PN (47 patients) for a renal mass in a solitary kidney. The researchers excluded patients treated with cold ischemia. They explained that no ischemia was used if a tumor was sufficiently exophytic or in a position where regional compression could provide sufficient hemostasis during tumor enucleation.
No ischemia was used in 96 patients (21%), whereas 362 patients (79%) had a median of 21 minutes of warm ischemia (achieved with hilar clamping). Compared with the no-ischemia patients, warm ischemia patients had a significant twofold increased risk of ARF and a fourfold increased risk of having a glomerular filtration rate (GFR) below 15 mL/min/1.73 m2 in the post-operative period, the investigators reported in European Urology (published online ahead of print).
In addition, of 297 patients with a preoperative GFR of 30 or higher, those treated with warm ischemia had a significant 2.3 times increased risk of new-onset stage IV CKD during a mean follow-up of 3.3 years.
“We do not submit that clamping should be avoided at all costs but rather support the use of no clamping in select patients with a tumor that is amenable to manual compression,” the researchers noted.
Dr. Thompson's group noted that their study is limited by its retrospective design. In addition, they pointed out that their study had a significant selection bias. Patients managed with no ischemia were likely to have more exophytic and smaller tumors that presented a lower risk of complications.