Background and Aims The chimney technique is a method for the left subclavian artery (LSA) reconstruction during thoracic endovascular aortic repair (TEVAR), with type Ⅰa endoleak being the main complication. The Longuette? chimney stent-graft is specifically designed for the chimney technique to reduce type Ⅰa endoleak during LSA reconstruction. To evaluate the efficacy of the Longuette? chimney stent-graft combined with TEVAR in the treatment of Stanford type B aortic dissection (TBAD) involving the LSA, we conducted a prospective, multi-center clinical trial (PATENCY clinical trial). This study was to summarize the one-year results and experiences of the PATENCY clinical trial.Methods From October 2018 to March 2022, twenty-six vascular surgery centers nationwide participated in the PATENCY clinical trial, enrolling a total of 150 eligible TBAD patients. All patients underwent LSA reconstruction with the Longuette? chimney stent-graft during TEVAR. The clinical efficacy and adverse events were evaluated during the perioperative period and at 12 months after operation, and the cumulative survival rate, LSA patency rate, and endoleak-free rate at one year after operation were analyzed.Results The patients' ages ranged from 30 to 77 years, with an average age of (54.48±11.12) years. Among them, 138 patients (92.0%) had concomitant hypertension; acute, subacute, and chronic TBAD accounted for 74.7%, 17.3%, and 8.0% of cases, respectively. General anesthesia was used in 124 patients (82.7%). The surgery success rate was 99.33% (149/150), with an average operative time of (91.67±41.47) min, X-ray exposure time of (31.36±16.71) min, and blood loss of (71.55±60.40) mL. The perioperative endoleak incidence was 5.33% (8/150), including type I in 6 cases, type Ⅱ in 1 case, and type Ⅳ and 1 case. One patient (0.67%) experienced acute occlusion of the Longuette? chimney stent, which was recanalized after another endovascular procedure. One patient (0.67%) had an acute cerebral infarction after operation, and two patients (1.33%) developed retrograde Stanford type A aortic dissection, with one death occurring three weeks after operation. Two patients (1.33%) died within postoperative 30 d. A total of 142 patients were closely followed for 11.67 (5-16) months. No displacement of the aortic stent or Longuette? chimney stent-graft was observed. Two type I endoleak patients underwent reintervention with embolization at six months and one year after operation, respectively. Six patients still had minor endoleaks at the one-year follow-up, but their TBAD false lumen remained stable without significant symptoms, and they received conservative treatment. Stenosis and occlusion within the Longuette? chimney stent occurred in one and two patients, respectively, with one case of retrograde Stanford type A aortic dissection. All these patients were asymptomatic and received conservative treatment. No complications such as stroke, paraplegia, or left upper limb ischemia were observed. The cumulative one-year survival rate, LSA patency rate, and endoleak-free rate were 97.96%, 97.96%, and 91.91%, respectively.Conclusion The use of the Longuette? chimney stent in endovascular treatment of TBAD for LSA reconstruction is simple, safe, and effective. It can significantly reduce the incidence of perioperative type Ⅰa endoleak, providing a new treatment option for minimally invasive management of aortic arch lesions.