[Clinical application of a modified double keystone design perforator island flap for repair of defects after excision of Bowen disease in posterior midline lumbar region].

Objective: To investigate the effectiveness of a modified double keystone design perforator island flap in repairing large skin and soft tissue defects in the posterior midline lumbar region following extensive excision for Bowen disease. Methods: A retrospective analysis was conducted on the clinical data of 9 patients with Bowen disease in the posterior midline lumbar region admitted between January 2020 and June 2024. There were 4 males and 5 females; ages ranged from 55 to 80 years, with a mean age of 68.9 years. Lesions were located at L Results: Operations were successfully completed in all 9 cases. The operation time ranged from 80 to 100 minutes (mean, 90 minutes); intraoperative blood loss ranged from 20 to 80 mL (mean, 41.1 mL); and the length of hospital stay ranged from 9 to 15 days (mean, 10.4 days). All flaps survived, with only 1 case of mild fat liquefaction at the recipient site. All patients were followed up 9-18 months (mean, 12.4 months). All flaps were similar in texture, thickness, and color to the surrounding skin, with no obvious "cat's ear" deformity observed. The lumbar mobility was normal, with no sensation of tightness or pain. At last follow-up, the subjective satisfaction, as assessed by the visual analogue scale (VAS) score, ranged from 7 to 10, with a mean of 8.7. No tumor recurrence was observed during follow-up. Conclusion: For large defects resulting from extensive resection of Bowen disease in the posterior midline lumbar region, the use of a modified double keystone design perforator island flap offers the advantages of reliable blood supply, uniform tension distribution, no need for skin grafting, and minimal trauma at donor site.