Bipolar vaporization: Do benefits outweigh risks?

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A large, randomized trial provides a head-to-head comparison of late complications involving the two approaches to BPH.

New Orleans-Despite the near absence of intraoperative bleeding, bipolar vaporization of the prostate is associated with a higher rate of postoperative than bipolar loop resection for the treatment of lower urinary tract symptoms secondary to BPH, reported Richard Santucci, MD, and colleagues at the AUA annual meeting.

Dr. SantucciIn particular, suggestions of late bleeding complications with bipolar vaporization were confirmed in a randomized clinical trial in which the two approaches were compared. “In clinical medicine, you often get the rumor of the problem before you get proof of the problem,” Dr. Santucci said.

In addition to an excess incidence of late bleeding, more irritative voiding symptoms in the early postoperative period surfaced with bipolar vaporization, which had also been the general impression all along.

“Everybody likes bipolar because it's speedy, easy, and causes no bleeding,” said Dr. Santucci, director of the Center for Urologic Reconstruction and specialist in chief, urology, at the Detroit Medical Center. “But you need to be aware that you may be trading a nice operation for a bad postoperative course including strictures, delayed bleeding, and increased urinary frequency. All surgeries have a cost-benefit ratio. This just better describes the cost-benefit ratio.”

Both bipolar transurethral loop resection of the prostate and bipolar button vaporization are minimally invasive surgical methods that are considered standard of care. Bipolar vaporization has become increasingly popular because it allows for concomitant vaporization and coagulation, resulting in near-zero intraoperative bleeding.

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“No one knew if the benefits of bipolar vaporization-almost no bleeding and a pretty easy technique-made it better than bipolar loop, which possibly is faster and provides tissue for histopathology,” he said. “A large randomized trial had not been done, and that’s the value of the study.”

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The relative safety profile of the two procedures was compared in 89 patients with BPH, who were randomized to surgery using either bipolar loop resection (44 patients) or bipolar button vaporization (45 patients). Eligible patients had a preoperative maximal flow rate (Q_max) <10 mL/sec, an International Prostate Symptom Score (IPSS) >18, and a prostate volume >40 grams. Patients were evaluated preoperatively and at 1, 3, and 9 months postoperatively by IPSS, uroflowmetry, and prostate ultrasound.

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Preoperative prostate volume was 59 grams and 58 grams (p=.52) in patients randomized to bipolar loop TURP and bipolar button vaporization, respectively, and IPSS was 19 and 20 (p=.38), respectively.

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Mean operative time was significantly longer in the vaporization group compared with the bipolar loop resection group (81 vs. 55 minutes; p<.001). Blood loss was less in patients randomized to bipolar vaporization compared with bipolar loop resection (0.8% vs. 2.0% drop in hemoglobin; p<.001).

Bipolar vaporization was associated with increased rates of postoperative urinary frequency (80% vs. 50%, p<.001), hematuria with clots up to 4 weeks after surgery (20% vs. 2%, p<.001), and postoperative urethral stricture (11% vs. 0%) compared with bipolar loop resection.

There were equivalent improvements in the bipolar vaporization and bipolar loop resection groups on the endpoints of postoperative Q_max (17 cc/s vs. 18 cc/s; p=.22), postoperative prostate volume (32 vs. 31 g; p=.31), and IPSS (6 vs. 5; p=.22).

Late postoperative bleeding with bipolar vaporization may be a function of the procedure, in which a 2- to 3-mm rind of highly coagulated prostate tissue remains after the prostate is vaporized, Dr. Santucci believes. “At 2 weeks, what may happen is that the rind of cooked tissue sloughs off, and then the fresh prostate underneath begins bleeding,” he told Urology Times.

The significantly increased rate of urethral stricture is “very disturbing,” he added. Although most operators would select the latest (fourth) button version of bipolar vaporization, “it could be that it’s not the right thing to do, and you should go back to version 3, which is bipolar loop,” he said.