Best practices for a rare disorder
Zenker's diverticulum (ZD) is a rare, benign outpouching of the pharyngeal wall just above the upper esophageal sphincter. It seems to result from incomplete relaxation of the cricopharyngeal muscle combined with muscle or tissue weakness in the esophagus. ZD occurs mainly in older adults, especially those in their 70s, 80s and 90s.
Not all diverticula cause problems, but food that becomes trapped in the pouch can lead to dysphagia that is often complicated by malnutrition and aspiration. Because the diverticulum frequently enlarges, symptoms progressively worsen over months or years.
ZD is traditionally managed by both surgical and endoscopic repair. Open surgery involves resecting the diverticular pouch through an incision in the neck. Options for nosurgical management have, until recently, been limited to rigid endoscopic cricopharyngeal (CP) myotomy. This procedure divides the septum between the diverticulum and esophageal lumen, allowing food to move more easily into the esophagus without resecting the diverticular pouch.
Like open surgery, rigid endoscopic CP myotomy is generally performed by ear, nose and throat surgeons using general anesthesia. And like open surgery, it can be complicated by substantial morbidity and mortality, particularly in older patients.
For that reason, a less invasive approach — flexible endoscopic CP myotomy — has generated considerable interest, says gastroenterologist Timothy A. Woodward, M.D., of Mayo Clinic in Florida.
He cites six published studies of the procedure, including one conducted at Mayo Clinic in 2010, involving a total of 200 patients. Of these, 85 percent experienced improved swallowing, with low complication and recurrence rates.
Flexible endoscopic CP myotomy is performed by endoscopists, often in an outpatient setting without general anesthesia. It takes less time than other procedures and patients resume oral intake more quickly. Dr. Woodward speculates that treatment and recovery times will improve further as skill sets evolve.
New tools, better results
Lasers, stapling or electrocautery have been used in flexible endoscopic CP myotomy since its introduction, but newer devices allow for more aggressive treatment.
"There are different modalities for addressing the septum," Dr. Woodward says, "but the literature supports the safety of using endoscopic dissection tools such as needle knives, hook knives and flex knives. These are all tools routinely used within the Mayo system that can also be used for Zenker's."
Dr. Woodward and John D. Casler, M.D., of the Department of Otolaryngology — Head and Neck Surgery/Audiology at Mayo Clinic in Florida, are currently leading a study of flexible endoscopic management of ZD. "What we are seeing more and more is that combined perspectives enhance both groups in terms of patient care," Dr. Woodward says.
The joint study will be a prospective registry, the purpose of which is to formalize and create best standards of practice. Study results should be available in early 2013.
"ZD is a disease of the elderly that profoundly affects quality of life because quality of life depends on eating," Dr. Woodward points out. "Finding a safe and effective treatment is an important and necessary goal."