Feedback about banding from my doc.

The state is investigating NYU Medical Center's booming weight-loss surgery practice, after three patients perished -- including a young lawyer who may have died of thirst -- following bariatric procedures, the Post has learned.

Drs. George Fielding and Christine Ren-Fielding, the glamorous husband-and-wife team in charge of the NYU unit, pioneered lap-band surgery -- in which a silicone band is looped around the stomach -- and performed it on Jet coach Rex Ryan.

"We're investigating the entire bariatric program" at NYU, said state Health Department spokesman Jeffrey Hammond.

The probe began within the last two weeks following complaints from ex-patients, a source said. The Post exposed new malpractice allegations against the Fieldings last week.

Weight-loss surgery is under scrutiny in New York, and new dangers are being alleged in litigation, including:

* At least six malpractice claims against the Fieldings -- one brought by ex-Met Lee Mazzilli, after his teenage daughter was hospitalized with stomach "perforations."

* 15 lawsuits against gastric-bypass surgeon Elliot Goodman at Manhattan's Beth Israel Medical Center in five years.

* Allegations that a Westchester hospital hid the weight of a patient -- who later died -- to qualify her for surgery.

Even as the feds consider making weight-loss surgery more accessible -- with lap bands for teens and patients on the cusp of obesity -- long-term risks are only now coming to light, nine years after FDA approval.

"The long-term risk of the band may be as high as 25 percent," said Dr. Paresh Shah, a surgeon at Lenox Hill Hospital.

Studies show the death rate for bariatric surgery is under 2 percent, but the research rarely accounts for deaths from complications after 30 days.

Christine Ren-Fielding admitted in an academic article that because some patients die months afterward, "the incidence of bariatric deaths in New York City is practically unknowable for us."

"After the surgery, [doctors] just sort of wipe their hands," said Lara Quatinetz, whose sister, Rebecca, 27, was found dead in her Stuyvesant Town apartment two months after NYU gave her a lap band in May 2008.

The young lawyer, who wanted to lose weight she'd gained while studying for the bar, couldn't swallow food or water for days on end, lawyer Howard Wexler claimed.

He claimed the band was cinched so tight -- despite adjustments made during six post-op visits -- that solids and liquids did not reach her stomach.

The Fieldings didn't respond to requests for comment, but George Fielding has claimed his NYU Program for Surgical Weight Loss, which operates on almost 1,000 patients annually, has "the lowest death rate in the world, in the history of bariatric surgery."

The Fieldings "are incredibly competent surgeons," Lenox Hill surgeon Mitchell Roslin said. "I would let either of them operate on me."

Bariatric procedures -- which are advertised in city subways and take as little as 20 minutes to perform -- are big moneymakers. NYU billed Rebecca Quatinetz more than $26,000. Surgeons say their cut is often around $4,000.

Critics worry greed has led to surgeries on patients with less-than-severe weight problems.

Joan Delango said that one clinic told her daughter, Danielle, that she didn't need a lap band but that Danielle, 25, got one at Lawrence Hospital Center in Westchester in 2008. Six weeks later, she died after collapsing in her bathroom, said Delango, who has filed a suit.

At the time of her death, Danielle weighed just 156 pounds, Delango said. Delango alleges that Danielle was listed as being shorter and fatter than she was so the surgery looked better to insurers and regulators.

On Danielle's presurgery form -- which the Post obtained -- a doctor wrote, "Do not weigh patient."

"I believe they changed her height and her weight to change her ideal numbers," Delango said. "Why else would you not want to weigh her?"