eMedicine - Transurethral Microwave Thermotherapy of the Prostate (TUMT) : Article by Jonathan Rubenstein, MD: "RELEVANT ANATOMY AND CONTRAINDICATIONS Section 4 of 11 Click here to go to the previous section in this topic Click here to go to the top of this page Click here to go to the next section in this topic
Author Information Introduction Indications Relevant Anatomy And Contraindications Workup Treatment Complications Outcome And Prognosis Future And Controversies Pictures Bibliography
Relevant Anatomy: The urinary bladder is derived embryologically from the urogenital sinus. The detrusor musculature makes up the bulk of the bladder and is stimulated mainly by the parasympathetic nervous system. The ureters enter the bladder at the corners of the trigone. The prostate, which originates from the mesenchyme surrounding the urogenital sinus, is a compound tubuloalveolar gland whose base abuts the bladder neck and whose apex merges with the membranous urethra at the urogenital diaphragm. The normal adult gland is cone-shaped and is 4.4 cm in transverse diameter across the base, 3.4 cm in length, and 2.6 cm in anteroposterior direction. Its blood supply is from the prostatovesicular artery, a branch of the inferior vesical artery from the hypogastric artery.
The nerve supply is from the pelvic plexus, which travels with the prostatovesicular artery. Alpha-adrenergic nerves innervate the prostatic stroma, capsule, bladder neck, and periurethral area, causing contraction and increased outlet resistance. The prostate is divided into zones. McNeal described the most commonly used division, which distinguishes the anterior, peripheral, transitional, and central zones.
Contraindications: Several general contraindications to all prostatic surgeries exist, such as active urinary infection or known or suspected prostate or urothelial cancer. Consider each of these before a treatment plan is instituted. Patients with neurogenic bladder voiding dysfunction should have their underlying neurogenic problem evaluated and treated.
Contraindications specific to TUMT are evolving as the technology changes and outcomes are studied further. Patients with a history of TURP or pelvic trauma should not undergo TUMT because of potential alterations in pelvic anatomy. Patients with glands that are smaller than 30 g or a prostatic urethral length of less than 3 cm respond poorly to TUMT, as do patients with glands greater than 100 g and patients with a prominent median bar.
Other contraindications include patients with metallic implants, penile prosthesis, severe urethral stricture disease, Leriche syndrome and/or severe peripheral vascular disease, or an artificial urinary sphincter. Patients with pacemakers need clearance from their cardiologists concerning turning their pacemakers off during therapy, although performing TUMT in this group should be approached with apprehension.
Hip replacement is no longer a contraindication. Acute urinary retention previously was thought to be a contraindication to TUMT. However, high-energy TUMT has shown promising results in this population, although efficacy has yet to be determined. Patients presenting in retention tend to be ill, with greater comorbidities; thus, they might benefit from the less invasive nature of TUMT."
