ObjectiveTo explore the technical feasibility, safety, and short- and long-term efficacy of totally portal minimally invasive thoracoscopic diaphragmatic folding assisted by a stapler for the treatment of symptomatic diaphragmatic eventration in adults. MethodsAretrospective study was conducted on patients with symptomatic diaphragmatic eventration who underwent totally portal minimally invasive thoracoscopic stapler-assisted diaphragmatic folding from August 2021 to February 2025. Surgical time, intraoperative blood loss, postoperative drainage volume, length of hospital stay, and complications were recorded. One month postoperatively, diaphragmatic position, lung function [forced expiratory volume in one second (FEV1), forced vital capacity (FVC) ], and symptom relief were assessed, with extended follow-up to 36 months to monitor long-term efficacy. ResultsA total of 7 patients were included, comprising 3 (42.9%) males and 4 (57.1%) females, with an age range of 34 to 66 years and a mean age of (56.4±12.5) years. All surgeries were successfully completed without conversion to open thoracotomy or intraoperative complications. The average surgical time was (44.29±11.47) minutes, intraoperative blood loss was (25.71±33.09) mL, and the postoperative length of stay was (2.00±0.58) days. One-month follow-up showed that the diaphragmatic position returned to normal anatomical levels, FEV1 improved from preoperative (1.93±0.33) L to (2.36±0.47) L, and the effective rate of clinical symptom relief reached 100.0%. Long-term follow-up (36 months) showed: (1) Pain scores decreased from (1.14±0.38) points at one month postoperatively to (0.14±0.38) points at three months postoperatively, remaining at 0 points at six months and thereafter; (2) All patients had stable diaphragmatic positions with no recurrence; (3) FEV1/FVC was ≥80% at three months postoperatively, with three assessable patients at six months maintaining ≥80%; (4) SpO2 remained ≥95% throughout, with no hypoxic events. ConclusionTotally portal minimally invasive thoracoscopic stapler-assisted diaphragmatic folding is a minimally invasive procedure with rapid recovery, significantly improving lung function and stabilizing diaphragmatic anatomical position. Follow-up at 36 months showed complete pain relief, no recurrence, and long-term stability of lung function, making it a safe and effective surgical option for treating symptomatic diaphragmatic eventration in adults. Long-term efficacy still requires validation with a larger sample size.