While patients looking to lose weight are turning in increasing numbers to laparoscopic gastric banding, or Lap-Band surgery, new research suggests the operation has a high complication rate, with up to half of patients opting to remove the band over the long term.

However, critics of the study say the band, the surgery and follow-up protocols have all improved since the patients included in the research had the procedure.

During the Lap-Band surgery, an inflatable, adjustable strap is wrapped around the stomach. The band curbs a patient's appetite and limits how much food he or she can eat, thereby leading to weight loss.

While patients credit the band with helping them drop significant amounts of weight, a new Belgian study that tracked patients for more than a decade after surgery found that 39 per cent of subjects experienced serious complications and nearly 50 per cent had the band removed within 12 years.

The findings are published in the journal Archives of Surgery.

Dr. David Urbach of Toronto Western Hospital said he finds the study's results worrying because they indicate "that these bands are not as safe as we previously thought over the long term."

Urbach told CTV News he has treated patients who were left in severe pain when their bands caused their stomachs to twist. In other cases, the band's plastic material had eroded into the stomach.

"Our sense is that as we see more bands put in, we're going to see more patients who want them removed either because of these types of complications or because their weight loss hasn't been satisfactory," Urbach said.

In some countries, such as Finland, patients can no longer receive Lap-Band surgery after studies concluded that as many as 40 per cent of patients had to have follow-up operations to treat complications.

But Dr. Chris Cobourn of Mississauga, Ont.'s Surgical Weight Loss Centre said the Belgian study was based on older techniques and older models of bands, and says patients did not receive adequate follow-up care.

"There have been significant changes in the way we do the procedure -- in the technique in the way we follow-up patients, and in the procedure," Cobourn told CTV News. "So the study is not relevant to today's practice."

The study's authors concede that their research included only a small number of patients who were treated at one institution, and that the procedure was in its infancy when the subjects first had surgery.

In fact, 60 per cent of the study's subjects reported being satisfied with the surgery. Of those that still had their band at the time of follow-up, their mean excess weight loss was 48 per cent.

"There is some evidence to suggest that the more recent 'pars flaccida' technique and the use of wider, softer bands provide better overall results than the 'perigastric' technique that we used at the time," the authors wrote.

But they maintain that their study shows the procedure "appears to result in relatively poor long-term outcomes."

A Canadian patient who spoke on condition of anonymity said despite the fact the band helped her lose 100 pounds, she found it uncomfortable, she suffered from infections and had the band replaced twice.

She says she turned to the band in desperation because she had tried unsuccessfully to lose weight through dieting, and advises others to "proceed with caution."

"It is quite unpleasant to live with, and down the road you may have complications."

With a report from CTV News medical specialist Avis Favaro and producer Elizabeth St. Philip