CHICAGO — Injection of adult autologous stem cells shows an excellent success rate for the treatment of urinary stress incontinence, compared with collagen injections, Dr. Matthias Schurich said at the annual meeting of the Radiological Society of North America.
In the study of both women and men, 50 (79%) of the 63 patients randomized to transurethral ultrasound-guided injection of adult stem cells were completely continent after follow-up lasting 6–30 months, compared with only 2 (7%) of the 28 patients treated with endoscopic injection of collagen after 6–12 months, he reported on behalf of principal investigator Dr. Ferdinand Frauscher and his colleagues at the Medical University Innsbruck (Austria).
The long, successful follow-up period for the stem cell injections is noteworthy because endoscopic collagen injections work well initially, but the effect is known to wear off relatively quickly, Dr. Schurich said in an interview.
The success rate for stem cell injections was significantly higher for women than for men, with 39 (93%) of 42 women continent and 11 (52%) of 21 men continent at follow-up.
This could be because most of the men had undergone radical prostatectomy with resulting scarring and little or no sphincter muscle remaining to be bulked up by the stem cells, explained Dr. Schurich, who is also with the university.
The autologous stem cells were obtained from skeletal muscle biopsies of the patient's arm and were cultured to yield roughly 50 million fibroblasts and 50 million myoblasts.
The fibroblasts were injected into the urethral submucosa, whereas the myoblasts were implanted into the rhabdosphincter.
Overall, the 63 patients (aged 36–84 years) were treated with autologous stem cells between September 2002 and February 2005.
During the same period, 21 women and 7 men (aged 31–84 years) also diagnosed with urinary stress incontinence were treated with standard transurethral endoscopic injections of collagen.
Patients were randomly assigned to the groups according to capacity in the cell culture laboratory.
Compared with baseline, the stem cell-treated patients demonstrated significant improvements in incontinence scores (5.95 vs. 0.44), thickness of the urethra (3.75 mm vs. 5.3 mm) and rhabdosphincter (2.10 mm vs. 3.30 mm), contractility of the rhabdosphincter (0.56 mm vs. 1.46 mm), and quality-of-life scores (51.3 vs. 104.0) at follow-up.
In addition to the 50 patients whose incontinence was cured, 6 had substantial improvement in symptoms and 7 experienced no improvement.
Incontinence scores and quality-of-life scores improved significantly among collagen-treated patients, but the improvements were “clinically irrelevant for the majority of patients,” Dr. Schurich said.
Urethral submucosa shows thinning of the rhabdosphincter (S) with atrophy (A).
After injection of stem cells, the sphincter appears hyperechoic (S). Photos courtesy Dr. Ferdinand Frauscher