Stomach pacemaker could help obese lose weight

Since having it implanted, Hetzner, a 20-year-old Munich mailman, has knocked off more than 10 kilos (22 pounds) from his earlier weight of 104 kilos (229 pounds).

Hetzner got the device as part of a clinical trial. Since being approved by Britain last month, the device is available for sale across the European Union. It works a bit like a cardiac pacemaker, and consists of a stimulator and a sensor surgically implanted onto the stomach.

The stimulator sends out electrical pulses meant to trick the stomach and brain into thinking the body is full. Hetzner said the pulses kick in a few minutes after he starts eating or drinking. He said they make him feel full after finishing about half the amount of food he would normally eat.

``It feels like a little pressure on my stomach or a tickle, but it's not a bad feeling,'' he said in a telephone interview.    

``It's been like a little guide to help me change my life,'' he said.

So far, about 65 patients in two studies have received the device from U.S. pacemaker manufacturer Intrapace. Only about half of those have had the pacemaker for at least a year, and most lost about 20 percent of their weight and kept it off.

Other stomach pacemakers are on the market but most are used to relieve symptoms like nausea and vomiting, not to fight obesity.

Appetite is partly controlled by signals sent from nerves around the stomach to the brain; the stomach pacemaker taps into that communication system, sending a message to the brain that the body is full after a relatively small amount of food is consumed.

``If you can stimulate the nerves going from the stomach to the brain, that should indeed have an effect in reducing food intake,'' said Stephen Bloom, an obesity expert at Imperial College in London, who is not connected to Intrapace or the clinical trials.

Bloom, however, questioned whether the device would work long-term, as people might eventually get used to the electrical pulses and keep eating anyway.

Doctors familiar with the pacemaker say there will always be ways for patients to eat and work around the system. ``We could make the (stomach pacemaker) work so people feel like they're going to throw up, but we don't want that,'' said Thomas Horbach, chief of surgery at Stadtkrankenhaus Schwabach, near Munich, who led one of the trials.

``If you take away all the responsibilities from the patient, they will not change on their own.''

As an additional benefit, the sensor tracks when patients eat, drink or exercise, so patients can chart their progress. Intrapace has also created an online network for patients to trade weight loss advice and share experiences.

Other surgical approaches to weight loss come with serious side effects.

People who have their stomach stapled or have a gastric band must eat smaller amounts of mostly low-fat foods, because their stomachs can't accommodate or process large volumes. If they overeat, they will feel nauseous, vomit, or suffer from other problems.

The most serious side effect seen in the pacemaker has been an infection linked to surgery. In Britain, the pacemaker costs about 15,000 pounds ($24,040), including the keyhole surgery used to implant it. Intrapace President Chuck Brynelsen said that's comparable to other weight loss surgeries.

The device is authorized for sale across the EU, though the company is first targeting weight loss clinics in Britain, Germany and Spain. It also plans to submit the device for approval in the U.S. once it has more data, and hopes it will be available there in 2014.

The pacemaker hasn't yet been implanted commercially in Europe, but Intrapace is in talks with clinics interested in offering it.    

Brynelsen said the battery in the device lasts about five years and it will be up to patients how long they want to keep the pacemaker. ``We don't know if patients will see (the stomach pacemaker) as a bridge to recovery or whether this is a crutch they will need for the longer term,'' he said.

Some experts said the pacemaker did not address people's underlying reasons for overeating. ``The problem with these devices is they assume people are rational and that they eat because they're hungry,'' said Stephan Rossner, a professor in the obesity unit at Karolinska University Hospital.

``A lot of obese patients eat because they're depressed, they can't sleep at night, or they have nobody to have sex with,'' he said. ``So whatever you insert into their stomach, they can out-eat that device because it's other things that drive them to consume.''

Hetzner said he intends to keep the stomach pacemaker for about four years.

``I don't want to backslide,'' he said, adding he would recommend the device to others. ``I want to be sure I can stick with it and that my body adapts to this new way of eating.''


<관련 기사>

<의학> 비만 치료용 식욕 조절장치 개발

(런던 AP=연합뉴스) 식욕을 반감시킴으로써 체중이 줄어들게 하는 비만 치료용 식욕조절장치가 개발됐다.

심박조율기 등 각종 조율장치(pacemaker)를 만드는 미국의 인트라페이스(Intrapace) 사가 개발한 이 식욕조절기는 위와 뇌에 전기충격을 보내 위가 찼다고  생각하게 하는 장치로 식사 시작 1-2분 후 작동된다.

이 장치가 작동되면 일상적인 식사량을 절반 정도 먹었을 때 배가 부른 것을 느끼게 된다.

식욕은 위장 주변의 신경들이 뇌에 보내는 신호에 의해 조절된다. 이  식욕조절기는 위장과 뇌의 이러한 교신에 끼어들어 위가 다 차지 않은 상태에서 배가 찼다는 신호를 뇌에 보낸다.

자극기와 센서로 구성된 이 장치는 심장병환자에게 사용되는 심박조율기와 비슷한 형태로 외과적 방법을 통해 복부에 삽입하게 된다.

독일 뮌헨에 사는 20세의 우편배달인 파트릭 헤츠너는 5개월 전 이  식욕조절기를 장치한 이후 지금까지 체중이 104kg에서 10kg 이상 줄었다.

그는 "이 장치로 배에 작은 압박감과 자극이 느껴지지만 기분 나쁠 정도는 아니다"고 말했다.

지금까지 약 65명의 비만환자를 대상으로 실시된 임상시험에서 절반이 최소한 1년 이상 이 식욕조절기를 계속 몸속에 달고 있으며 이들은 대부분 체중이 20%  줄었다.

이 식욕조절기를 몸 안에 설치하려면 키홀(keyhole) 수술비를 포함, 약 2만4천 달러의 경비가 든다.

이 식욕조절기를 작동시키는 배터리는 수명이 약 5년이고 이를 언제까지 위에 장치할 것인지는 환자의 결정에 달렸다. 헤츠너는 앞으로 4년 더 이 장치를 지니고 살겠다고 말하고 있다.

지난달 영국 보건당국으로부터 승인을 받은 이 식욕조절기는 아직 임상시험  단계이지만 유럽연합(EU) 전역에서 사용이 가능하다.

인트라페이스 사는 임상시험 자료가 더 모이면 미국식품의약국(FDA)에 승인을 신청할 계획이며 2014년에는 미국에서도 사용할 수 있게 될 것으로 기대하고 있다.

그러나 스웨덴 카롤린스카 대학병원의 비만전문의인 스테판 로스 (Stephan Rossner) 박사는 이 장치는 순전히 비만환자가 배고파서 먹는다는 전제 아래 만들어진 것이기 때문에 문제가 있다고 지적했다.

비만환자는 기분이 우울해서, 밤에 잠을 이룰 수 없어서 또는 섹스상대가  없어서 먹을 때가 많은데, 이 때도 식욕조절기가 효과가 있을지 의문이라는 것이다.