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Russell Milligan
Presence Saints Mary and Elizabeth Medical Center


After Eight Long Years, Surgeon at Presence Saints Mary and Elizabeth Receives Patent Approval on New Dialysis Shunt

Nazir Khan, M.D.Chicago, Ill. – November 26, 2012 -- Nazir Khan, M.D. (pictured at right), of Presence Saints Mary and Elizabeth Medical Center (PSMEMC) knows all about operating rooms. Last summer, the cardiovascular-thoracic surgeon showed he could successfully operate in a setting normally dominated by attorneys and engineers – a hearing room for the U.S. Patent and Trademark Office.

Persistence paid off for Dr. Khan who spent the last eight years seeking patent approval for a new Hybrid Arteriovenous Shunt for chronic renal failure patients on dialysis. On Oct. 9, Dr. Khan was granted a patent by the U.S. Patent and Trademark Office. His dream had come true.

In 2003, Dr. Khan came up with the idea for this first-of-its kind shunt that allows patients to be hooked up to hemodialysis, a process that purifies the blood when a person’s kidneys are not working properly.

The patented design affects two hemodialysis devices currently in use: the conventional hemodialysis shunt and the permacath double lumen catheter.

In a conventional arteriovenous (AV) shunt, a graft connects an artery to a vein, and blood at high pressure flowing into the vein can cause vein-wall damage. In 80 percent of the cases, the conventional shunt will lead to AV graft failure in three years. Dr. Khan invented a hybrid arteriovenous shunt where the blood after dialysis goes into the right side of the heart without any contact with a vein wall. This design eliminates 80 percent of shunt failure.

A double lumen catheter uses venous blood for purification by the dialysis machine and is deposited back into the right side of the heart. This catheter comes out on the chest wall and this approach is associated with a higher rate of infection, poor performance and mortality. Dr. Khan’s hybrid shunt replaces the double lumen catheter – reducing the likelihood of infection and mortality.

“This new shunt only will be used in patients where peripheral access sites to the veins are exhausted and no longer options for treatment,” said Dr. Khan, who joined PSMEMC in 1983.

In 2004, Dr. Khan submitted his first application for a patent and was rejected by examiners, who cited four prior patents. Working with a patent attorney, Dr. Khan submitted applications for four years and was denied each time. At that point, he decided to handle the case himself without a patent attorney.

In 2010, Dr. Khan argued the case before the trial court of the Board of Patent Appeals and Interferences (BPAI) in Washington, D.C., and won 19 claims out of 20. Dr. Khan appealed to the court to reopen the case because the examiners’ assertions about prior patent rejections were irrelevant. The court agreed and reopened the case.

In June 2012, he finally had an opportunity to personally present his case before the BPAI in Washington, D.C. He presented his invention before a panel of three judges who heard the case in 25 minutes.

In August 2012, Dr. Khan learned that his shunt had been approved. The U.S. Patent and Trademark Office granted the patent on Oct. 9 – eight years after his initial application. Dr. Khan has begun discussions with a manufacturer for creation of the shunt. Once developed, Dr. Khan will seek approval from the U.S. Food and Drug Administration. Then he will be required to test the shunt on 10 to 20 patient cases. If all goes smoothly, Dr. Khan hopes to begin the clinical study in 2013.

“I was so very happy that eight years of struggle paid off,” Dr. Khan said. “I was persistent and it finally paid off.”

The patent is available online at

About Presence Saints Mary and Elizabeth Medical Center (PSMEMC)
PSMEMC is a premier medical center on Chicago’s near northwest side and includes the: Saint Mary Campus, 2233 W. Division St., and Saint Elizabeth Campus, 1431 N. Claremont Ave. The Saint Mary Campus is certified as a Primary Stroke Center and accredited as a Chest Pain Center. The hospital specializes in cardiac care, digestive diseases, emergency services, neuroscience services, obstetrics, primary care, behavioral health and wound healing. PSMEMC ranks No. 19 in the 2012-13 U.S. News & World Report’s “Best Hospitals” in the Chicago metro area. PSMEMC offers comprehensive diabetes care and education for inpatients and outpatients. Click here for information the medical center’s diabetes services. Visit our website at

About Provena Health – Resurrection Health Care, Now Joined as Presence Health
PSMEMC is part of Presence Health, a family of Catholic, not-for profit, healthcare services providing advanced medical care and exceptional service with compassion and hope. With locations in Chicago and its collar counties, as well as in East-Central Illinois, it is the largest Catholic health provider in Illinois, encompassing 12 hospitals, 27 long term care and senior residential facilities, numerous outpatient services, clinics, home health services, hospice, private duty, and comprehensive Behavioral Health services. Presence Health is sponsored by the Franciscan Sisters of the Sacred Heart, the Servants of the Holy Heart of Mary, the Sisters of the Holy Family, Sisters of Mercy of the Americas and the Sisters of the Resurrection. Visit to learn more.   


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