The effect of preoperative chemoradiotherapy on the latency of the genital nerve and the contractility of the anal sphincter

Abstract

Aim. To study the effect of chemoradiotherapy on the latency of genital nerves and contractility of the anal sphincter in patients with rectal cancer. Methods. Analyzed were 20 cases of rectal cancer T2-3NXM0 (12 males, 8 females). Complex treatment included preoperative chemoradiation therapy (total focal dose 47 Gy, fluorouracil - 2.5-3 g, cisplatin - 90 mg), surgical intervention and postoperative adjuvant chemotherapy for the period from 2009 to 2010. Before the initiation and after the chemoradiotherapy conducted was an evaluation of latency of the genital nerve and needle electromyography of the anal sphincter. Results. Due to the conduction of chemoradiotherapy the median latency of the right branch in males increased significantly from 2.9 to 4.3 ms, in females from 2.1 to 2.4 ms. The increase in the latency of the left branch of the genital nerve was observed in males (from 5.4 to 10.9 ms), while in women registered was a decrease of the indices (from 4.3 to 2.5 ms). A significant reduction of the potential of the external sphincter at rest (from 226.5±157.3 to 196.9±141 mV) and during conation (from 369.7±226.4 to 262.4±138.1 mV), regardless of gender. Conclusion. Conduction of preoperative chemoradiotherapy for cancer of the lower and middle ampullary part of the rectum leads to a decrease in the conduction speed along the genital nerve predominantly in male patients, and is accompanied by a decrease in electrical potentials of the external anal sphincter.

Keywords

rectal cancer / latency of sexual nerves / external anal sphincter

References

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RIGHTS & PERMISSIONS

Shelygin Y.A., Rasulov A.O., Dzhanaev Y.A., Boyko A.V., Droshneva I.V.