The Neo-Urinary Conduit, for which Tengion is currently conducting a Phase 1 clinical trial, is a physiologically functional tissue with a three-dimensional structure that diverts urine from the ureters to a removable, disposable bag, or ostomy bag, outside the body after removal of the bladder. The Neo-Urinary Conduit is being developed for the treatment of patients who require removal of their bladder in connection with the treatment of bladder, abdominal or pelvic cancer, or other severe bladder disease, and offers a number of benefits compared to the standard of care.
Current treatment for patients undergoing cystectomy is creation of a conduit or bladder replacement with the use of bowel tissue. The purpose of the Neo-Urinary Conduit is to avoid the complications associated with removal and use of bowel tissue to deconstruct the urinary tract and urine excretion. Such complications include:
- Complex surgical procedure and lengthy peri-operative procedures and recovery.
Current standard-of-care has a prolonged and complicated surgical procedure involving the bowel and is associated with comorbidities in up to 70% of patients. By replacing the use of bowel tissue, which absorbs urine, with impermeable urinary tissue, the patient’s metabolic, physiological, and overall health are improved leading to potentially improved post-operative recovery.
- Bowel complications. Early complications are usually related to the bowel surgery required to harvest tissue for reconstructive use and typically consist of leaks, fistulas and obstructions. Malabsorption of various nutrients, salts and lipids can lead to diarrhea and metabolic instability. Because vitamin B12 is absorbed in the bowel tissue, the loss of tissue can result in anemia and neurologic abnormalities. Patients with ileal conduits are prone to bowel movement problems even before surgery and the removal of bowel tissue may either exacerbate existing conditions or create new motility problems. These conditions further contribute to the substantial physical and psychological morbidity in patients using the current standard of care.
- Absorption issues. Use of bowel tissue often leads to electrolyte and metabolic imbalances, which can cause bone loss. Certain drugs taken by the patient may be reabsorbed by the implanted bowel tissue, potentially leading to unintended toxic levels and side effects. The exposure of intestinal surface to urine also results in the inappropriate absorption of ammonium, chloride and hydrogen ions as well as potassium loss, leading to chronic metabolic imbalances or abnormalities.
- Infection. Persistent and recurrent infections are typical in patients with bowel tissue reconstruction. Infections may reach the kidney and become life-threatening. Bacteria normally found in bowel tissue can serve as a source of infection and septic complications when bowel tissue is placed into the urinary tract.
- Stone formation. One of the consequences of persistent infection is the development of stones.
Stones are hard masses which can cause pain, bleeding, obstruction of urine or infections. Urinary tract obstruction damages the kidneys and can lead to hospitalizations and long-term medical problems.
- Mucus. Bowel tissue, when repositioned in the urinary tract, continues to secrete mucus.
Mucus increases the risk of stone formation and the viscosity of urine, and in the case of bladder augments, may require bladder irrigation and more frequent catheterization.