犬舌黏膜与颊黏膜组合移植重建尿道的实验研究

目的 探讨犬舌黏膜与颊黏膜组合移植替代尿道的可行性和有效性. 方法杂种雌犬7只,平均体质量13 kg,剥离尿道黏膜4 cm×1 cm,取2 cm×1 cm舌侧面黏膜和颊黏膜各1条,拼接后移植至尿道内,恢复尿道黏膜的连续性.术后留置硅胶导尿管1周,拔除尿管后观察排尿情况.1.5～12.0个月后行逆行尿道造影检测实验犬尿道通畅情况,并用10 F尿管证实有无狭窄.随后处死实验犬,测定移植物长度并行病理组织学检查,观察舌黏膜与颊黏膜组合移植至尿道后组织学改变情况. 结果7只实验犬均存活,排尿通畅6只,发生尿道狭窄1只;无尿瘘.移植手术前后舌黏膜和颊黏膜拼接长度分别为(4.00±0.15)和(3.75±0.23)cm,差异有统计学意义(P＜0.05).排尿通畅犬移植黏膜存活良好;舌黏膜与颊黏膜交界处愈合良好,无狭窄发生;光镜下见鳞状上皮呈连续分布,拼接移植黏膜的鳞状上皮与尿道的移行上皮区分明显,移植黏膜的鳞状上:皮有渐被尿道移行上皮替代的趋势.结论 犬舌黏膜和颊黏膜组合移植可替代尿道黏膜并恢复尿道的连续性.

Combined buccal mucosa and lingual mucosa grafts for urethroplasty:an experimental study in dogs

Objective To evaluate combined buccal mucosa and lingual mucosa grafts for urethroplasty in a dog model. Methods Seven female mongrel dogs were selected.After a segment of proximal urethra mucosa (4 cm×1 cm) was excised and onlayed,urethroplasty was performed by using the combined free buccal mucosa (2 cm×1 cm)graft which had been harvested from the inferior cheek and free lingual mucosa graft(2 cm×1 cm)harvested from the inferior lateral surface of the tongue.A 12 F urethral catheter was kept for 7 d.Retrograde urethrography was done and urethra diameter was calibrated with a 10 F catheter before animals were sacrificed at week 12.Then the grafted areas excised and evaluated grossly and histopathologically. Results All dogs survived during the procedure and there was no tongue or bueeal complications.One dog developed a severe urethral stricture at the proximal anastomosis site.The remaining 6 dogs voided spontaneously with no difficulty.Retrograde urethrography showed that no stricture or fistula formed.The combined buccal mucosa graft and lingual mucosa graft shortened from a mean (SD) of 4.00(0.15)to 3.75(0.23)cm (statistically.significant,P＜0.05).No stricture was found in the connection of the buccaI mucosa and lingual mucosa grafts.Histological examination showed that the combined buccal mucosa and lingual mucosa grafts were well-incorporated into the urethral walls and covered by a keratinized squamous epithelium.Neovascularization was evident beneath the grafts. Conclusion Combined buccal mucosa graft and lingual mucosa graft could be an option for urethral substitution.