Moderator: Joseph Grocela, MD, MPh, Instructor in Urology, Harvard University; Assistant in Surgery (Urology), Massachussetts General Hospital, jgrocela@partners.org

4:00PM Current State of Managing Voiding Dysfunction
Shahin Tabatabaei, MD, Instructor in Surgery (Urology) and Assistant Urologist, Massachusetts General Hospital, stabatabaei@partners.org

In the United States, over 34 million people suffer from problems involving the bladder, and these problems can significant reduce one’s quality of life. The bladder, a distensible organ that sits behind the pelvic bone, is composed of 50 % collagen (a structural protein), 2 % elastin (a protein responsible for the bladder’s elasticity), and assorted matrix macromolecules. The percentage of collagen increases with age while the percentage of elastin does not change, so the bladder gradually loses it stretchiness over time. The bladder is surrounded by an elastic layer of cells known as the urothelium, a layer that is practically impermeable to ions and urea. The bladder fills passively and is capable of expanding in volume from almost nothing to over 500 mL. The entire organ is surrounded by smooth muscle, and nearby organs and muscles give the bladder a complex, not perfectly spherical, shape. There is poor electrical coupling between the smooth muscle cells surrounding the bladder, so any synchronized contraction, such as that which empties the bladder, must be initiated by the nervous system. In healthy adults, urinating is voluntary, but many physiological problems can cause one to lose some degree of control over the bladder.

Overactive bladder (OAB) affects from 9 % to 16 % of the population and is defined by feelings of urgency, with or without urge incontinence, that are accompanied by frequent and/or nighttime urination. The prevalence of overactive bladder syndrome rises with age. The first line of treatment involves anti-muscarinic drugs, which block the connection between the peripheral nervous system and the muscles that cause the bladder to contract. When a patient takes these drugs, the muscle surrounding the bladder relax. If a patient’s symptoms don’t respond to pharmacotherapy, surgical options can be considered. Sacral neuromodulation, for example, can be used to stimulate certain nerves going to the bladder, but the technique is still in its infancy.

Bladder cancer is another serious problem that affects the bladder. It is the fourth most common cancer in men, and its incidence is slowly rising. Initial symptoms often include blood in the urine (hematuria), feelings of urgency, and frequent urination. Tumors can be either benign or malignant, and they can sometimes extend into the urothelium or even to the smooth muscle below. Transurethral resection of the tumor is usually the method used to diagnose and treat the cancer. After a diagnosis is made, if there are multiple tumors, laser therapy can be used to remove remaining tumors. Finally, to treat some tumors, high doses of chemotherapeutic drugs can be temporarily introduced into the bladder knowing that the urothelium will prevent these drugs from entering systemic circulation. Interestingly, an attenuated tuberculosis bacterium (bacillus Calmette-Guerín, or BCG) can be used in place of drugs. In the future, urologists hope to answer lingering questions about how to best follow up on cancer survivors, and they are also seeking ways to make the entire diagnostic and therapeutic process less invasive for patients.

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5:05PM Medicine Delivery Methods for Overactive Bladder, Interstitial Cystitis and Bladder Cancer
Michael Cima, PhD, Sumitomo Electric Industries Professor of Engineering, Massachusetts Institute of Technology, mjcima@MIT.EDU

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