Mayo Clinic Says Open Nephron-sparing Surgery Remains The 'Gold Standard'

"By comparing the first decade of elective open surgeries with morecontemporary ones, we found that patient outcomes have greatlyimproved," says Michael Blute, M.D., Mayo Clinic urologist and leadinvestigator of the study. "This leads us to the understanding thatwhile there are some new treatment options out there, what was once theonly option (open NSS) is still quite often the best option."

Prior to 1985, open NSS was only done on patients with onekidney while patients with two kidneys and cancer in one automaticallyhad the entire kidney removed. In the mid-1980s, Mayo Clinic began touse open NSS to treat patients who still had a healthy second kidney.This led to increased quality of life and fewer patients whosubsequently had to resort to dialysis.

Since then, laparoscopy has evolved as another commonly used treatment,often considered superior in other types of surgery. Initial studiesshowed that laparoscopic NSS is feasible for small, easily accessiblekidney tumors, making it appear the more favorable option. However, Dr.Blute and his colleagues have found that may not be true for manycases, especially when large or complex tumors are involved. "It's verydifficult to safely and accurately remove a complex kidney tumor withlaparoscopic NSS," explains Dr. Blute, "and if you find some cancerremaining when you look at the tissue under the microscope, it isdifficult to remove more tissue like you can when doing an open NSS."

Dr. Blute and his co-investigators reviewed all open NSS proceduresperformed at Mayo Clinic between 1985 and 1995, and compared them tothose performed between 1996 and 2001. They found that the procedurehas gotten increasingly better results over time, and attributed thisto increased surgeon experience, improved anatomical imaging, andenhanced perioperative care. For example, hospital stay declined from amedian of seven days to five days, blood loss and transfused units ofblood significantly decreased, early complications declinedconsiderably, and urine leak occurrence was demonstrated in only 0.6percent (compared to previous reports as high as 17 percent). They alsofound declines in the rates of dialysis need and other long-termcomplications.

When studying the more recent surgeries, researchers also found thatopen NSS showed some benefits compared with laparoscopic NSS. Whilelaparoscopic NSS can often offer patients reduced postoperative pain,shorter hospital stays and smaller scars, it carries some risks thatopen NSS actually lessens. For example, Mayo Clinic surgeons needed toclamp the renal artery, stopping blood flow to the kidney, in only 50percent of open NSS surgeries. For the majority of similarly complexlaparoscopic NSS, this artery is clamped for durations typically muchlonger than those required for open NSS. The importance of limitingartery clamp times was indicated by fewer early surgical complicationsseen in patients with 20 minutes or less of stopped blood flow.

Dr. Blute's team concluded that open NSS remains the standard by whichother treatments should be evaluated. "While there is a definitebenefit for many patients with tumors on the kidney's surface to havelaparoscopy," says primary author R. Houston Thompson, M.D., "we findthat NSS via an open approach remains the best option for patients withcomplex kidney tumors. In addition, we are now performing open NSSthrough mini-incisions of less than five inches, which reduces pain andhelps with a speedy recovery."

This study reviewed records of all patients undergoing open NSS between1985 and 2001. The records were obtained from the Mayo ClinicNephrectomy Registry, which includes over 4,000 patients who underwenteither NSS or radical nephrectomies since 1970.

In addition to Dr. Bluteand his co-investigator, Dr. Thompson, the Mayo Clinic research teamincluded Bradley Leibovich, M.D.; Christine Lohse; and Horst Zincke,M.D., Ph.D.

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