Vent for Emphysema:A Minimally Invasive Approach to Breathing Easy

Vent for Emphysema: A Minimally Invasive Approach to Breathing Easy

The Emphasys Endobronchial Valve (EBV™) is designed to redirect airflow to healthier lung segments by blocking inhaled air to the diseased portion. Upon exhalation, trapped air is intended to be vented out (as shown in illustration), creating the potential for non-surgical bronchial lung volume reduction. CREDIT: Courtesy of Emphasys Medical, Inc.™

For patients with emphysema, a lung disease typically caused by cigarette smoking, the fundamental act of breathing becomes a battle. Approximately two million Americans are affected by emphysema, and the vast majority are over age 50. Emphysema occurs when damage to the air sacs affects the elasticity of the lungs, trapping air in the lungs and enlarging the chest wall. In lung volume reduction surgery (LVRS), those parts of the lung most affected by emphysema are surgically removed in order to improve the function of the rest of the lung. After LVRS, patients typically experience less shortness of breath and improved quality of life. In a new clinical trial, the Endobronchial Valve for Emphysema Palliation Trial (VENT), physician-scientists at Columbia are investigating the potential benefits of a less invasive approach to lung reduction.

The VENT trial builds upon the findings of the five-year, multi-center National Emphysema Treatment Trial (NETT), published in The New England Journal of Medicine in May 2003. This landmark study was administered by the National Institutes of Health (NIH) in cooperation with the Centers for Medicare and Medicaid Services (CMS) and was spearheaded at Columbia by Mark E. Ginsburg, MD, Assistant Clinical Professor of Surgery at Columbia University College of Physicians & Surgeons and Surgical Director of The LeBuhn Center for Chest Disease and Respiratory Failure at NewYork-Presbyterian Hospital/ Columbia University Medical Center, along with Byron M. Thomashow, MD, Associate Professor of Clinical Medicine at Columbia and Medical Director of The Courtesy of Emphasys Medical, Inc.™ LeBuhn Center for Chest Disease and Respiratory Failure.

The objective of the NETT was to compare the best medical treatments available with LVRS in patients with severe emphysema. The study demonstrated that in select patients, LVRS significantly reduced both shortness of breath and mortality as compared to medical management alone. As a result of the NETT, the CMS approved coverage for bilateral LVRS in designated centers of excellence, such as Columbia.

Dr. Ginsburg and his co-investigator of the VENT trial, Roger A. Maxfield, MD, Associate Clinical Professor of Medicine at Columbia University College of Physicians & Surgeons, are now hoping to dig a bit deeper into LVRS and reveal the benefits of the new minimally invasive approach. "With the VENT study, we're testing if the Emphasys Endobronchial Valve (EBV™) procedure can be performed effectively through an airway. The EBV™ is an implantable device—it's essentially a one-way valve designed to allow trapped air to vent from the isolated lung segment during exhalation while preventing air inflow during inhalation," explains Dr. Ginsburg.

The Emphasys Endobronchial Valve (EBV™) is designed to redirect airflow to healthier lung segments by blocking inhaled air to the diseased portion. Upon exhalation, trapped air is intended to be vented out (as shown in illustration), creating the potential for non-surgical bronchial lung volume reduction.
"Right now lung reduction surgery is done as an open-chest operation, and it has fairly significant morbidity associated with it," he continues. "If we could take away the trauma of the procedure, we would gain a lot in terms of patient outcomes. The minimally invasive procedure could provide a much faster recovery time; the hope is that patients will stay in the hospital for less than 48 hours—versus an average stay of 9-10 days after open lung reduction. It would also be a less costly procedure."

VENT is a multi-center, randomized, prospective clinical trial designed to primarily study the safety and effectiveness of the EBV™ procedure. Of the 20 centers participating in the trial, Columbia is the only center based in the tri-state area. To be eligible for the trial, patients must have severe emphysema, with the worst damage prevalent in the upper lungs. All patients will be required to undergo pulmonary rehabilitation before and after surgery, and patients will be followed for 18 months after randomization.
"If our outcomes prove as promising as I suspect, then this would be another step forward beyond the NETT—and a major advancement for treating patients with severe emphysema," adds Dr. Ginsburg.

For more information about the VENT trial (IRB# AAAA0812), please contact Dr. Ginsburg at 212.305.1158.

An engineered lung worked when implanted into a rat

An engineered lung worked when implanted into a rat.

Ker Than for National Geographic News Published June 2010

For the first time scientists have reconstructed working lungs in the lab and transplanted them into a living animal.

The achievement is a breakthrough in biomedical engineering that could lead to replacement lungs for humans in the near future, experts say.

Currently, the only way to replace diseased lungs in adults is a lung transplant, a high-risk procedure that's vulnerable to tissue rejection.

In a new study, researchers took lungs from a living rat and used detergents to remove lung cells and blood vessels, revealing the organ's underlying matrix.

This lung "skeleton"—made of flexible proteins, sugars, and other chemicals—consists of a branching network that divides more than 20 times into smaller and smaller structures. (See an interactive graphic of lung structure.)

The researchers placed these "decellularized" lungs into a bioreactor, a machine filled with a slurry containing different types of lung cells extracted from rat fetuses.

(Related: "Scientists Grow Lung Cells From Stem Cells.")

Within several days, the fetal cells naturally attached to the lung matrix and formed a functional lung.

"By and large, the correct subsets of cells went to their correct anatomical locations," explained study leader Laura Niklason, a biomedical engineer at Yale University. "It appears that the lung matrix has cues, or 'zip codes,' that tell the cells where to land."

When the team implanted the engineered lungs into an adult rat for short periods of time—between 45 minutes and two hours—the lungs exchanged oxygen and carbon dioxide in the same way as natural lungs.

"Leap Forward"
By using a natural lung matrix, Niklason's team has avoided one of the biggest hurdles of lung-regeneration attempts—finding a suitable "scaffold" for lung cells to attach to.

Because manufacturing techniques cannot yet replicate nature's complex design, attempts to create synthetic scaffolds have been unsuccessful.

Niklason spent several years trying to create a synthetic lung scaffold, but in the end concluded it was too difficult.

"I decided I couldn't do it, and probably nobody else could either," she said.

The new research represents a "real leap forward" in lung regeneration, said Peter Lelkes, a biomedical engineer at Drexel University in Philadelphia.

"People have engineered organs such as bone and cartilage before, but by comparison to the lung, these are all kids' games," added Lelkes, who was not involved with the study.

Stem Cell Hurdle
Niklason estimates it will be about 20 to 25 years before her team's technique can be used in humans.
That's because a few technical and scientific challenges remain.

Chief among these is finding ways of creating stem cells—which can transform into any other type of cell—from patients with lung disease. No techniques currently exist for creating such cells, which would carry no risk of immune rejection.

(Related: "Liposuction Fat Turned Into Stem Cells, Study Says.")

"The stem cell issue," Niklason said, "is really the big fundamental scientific hurdle."

The research is detailed in this week's issue of the journal Science.

Image courtesy Science/AAAS

Artificial Lung Closer to Clinical Trial ?

Artificial Lung Closer to Clinical Trial


Clinical Trials
After nearly a decade at the drawing board, "We are looking at what we consider final design changes," Merz says. Clinical trials may get under way in one to two years. The National Institutes of Health recently granted Bartlett $4.8 million to continue the research.

Early animal studies have been promising. In the latest study, University of Texas researcher Joseph Zwischenberger, MD, tried out the BioLung on sheep whose lungs had been badly burned by inhaling smoke. Six of the eight sheep on the BioLung survived five days, whereas only one of six sheep on an external breathing machine survived that long.

Meanwhile, Bartlett has been testing the waters for future human trials. "What we wanted to do was see what the transplantation centers were thinking," he says. So he sent them a survey.

Thirty-one transplant centers completed the survey -- and those were responsible for 72% of all lung transplants in the United States in 1999. Most said they would like to see the BioLung studied in fewer than 25 animals for 30 days before beginning to test the device on humans. Almost all of them said they would support and participate in a clinical trial.

"The FDA would have the final word," Bartlett says. "This is just a start."

A one-month study on two dozen animals may seem hasty, but the situation is dire. Last year, 1,054 people received lung transplants, but 477 died on the waiting list. As of August this year, 3,797 people were still waiting to be matched to a donor.

Most of the transplant centers that responded to Bartlett's survey said the device should be tested first on people with idiopathic (meaning "of unknown cause") pulmonary fibrosis. Among the sickest of these patients, few survive longer than three months.

see more info at
http://www.webmd.com/lung/features/artificial-lung-closer-to-clinical-trial?page=2

Doctors are currently experimenting with artificial lungs

So just how close are we to being able to create a bionic person?



LUNGS
Doctors are currently experimenting with artificial lungs as a way to give patients waiting for a donated lung an increased chance of survival.

One such device is the BioLung, a machine which is roughly the size of a drinks can that is implanted in the chest. The device is packed with hollow plastic fibres perforated with holes so tiny that only gas molecules can pass through them.

As blood filters through the fibres, carbon dioxide escapes through the holes and is replaced by oxygen from the surrounding air.

Researchers claim it can reproduce 100 per cent of normal lung function. Clinical trials are expected to be under way in the next few years.

BIONIC HAND
Not dissimilar to Will Smith's arm in the film I, Robot, in 2007 there was a bionic revolution close to home when Livingston-based company Touch Bionics introduced the first commercially available bionic hand.

LEG
Earlier this year a biotech company in New Zealand revealed that it had created a pair of robotic legs which had helped a man walk again.

The device is not an implant, but rather a robotic exoskeleton, or Rex - a pair of robotic legs that support and assist a person who usually uses a wheelchair. Users strap themselves in and control their movements using a joystick and control pad.

see more om medical progress and lung