Tracheal replacement with an aortic autograft.

Tracheal replacement after extensive resection remains a challenge for the thoracic surgeon. We propose an innovative solution: the use of an aortic autograft. After an experimental work on animals with aortic autografts and allografts [Martinod E, Seguin A, Pfeuty K, Fornes P, Kambouchner M, Azorin JF, Carpentier AF. Long-term evaluation of the replacement of the trachea with an autologous aortic graft. Ann Thorac Surg 2003;75(5):1572-8; Martinod E, Seguin A, Holder-Espinasse M, Kambouchner M, Duterque-Coquillaud M, Azorin JF, Carpentier AF. Tracheal regeneration following tracheal replacement with an allogenic aorta. Ann Thorac Surg 2005;79(3):942-8], we present the first human case of long tracheal replacement with an aortic autograft. In this case we replaced 7 cm of a tumoral trachea using an aortic infra-renal autograft supported by a silicone stent. The early postoperative course was uneventful. The stent was removed at three months. The patient died at six months from an acute pulmonary infection without any sign of anastomosis leakage or graft rupture. A new field of clinical study has to be investigated.     

Circumferential tracheal replacement with costal cartilage

Long-term incorporation of foreign material or tissue in circumferential tracheal replacement will lead to progressive growth of granulation tissue, provoking either airway stenosis or a reduction of subepithelial blood supply and thereby preventing the appearance of functioning ciliated epithelium in the replaced segment. In experience with dogs, a 5 cm length of the thoracic trachea was replaced circumferentially with fresh autogenous untreated circularly positioned cartilage-perichrondrium strips. During the period of strengthening of this neotracheal wall, a temporary tracheal prosthesis made of tubular silicone rubber with absorbable sewing rings of polyglactin 910 placed 3 mm from the end of the tube served as a tracheal replacement. Six months after the cartilage transplantation, the neotracheal wall had stabilized sufficiently for the silicone rubber tube to be extracted with an endoscope. Four weeks after extraction of the silicone rubber tube the neotracheal segment was completely covered with ciliated epithelium over a thin subepithelial, well-vascularized layer. Subepithelial vessels had a diameter of 180 microm. They were a continuation of the intercartilaginous main vessels of the neotracheal wall. The presence of normal cilia on the epithelium was proved through transmission electron microscopy. Even the tubules of the cilia were arranged in the right order. In the ink test, movement of the transport marker across the neotracheal segment at a speed of 18 to 21 mm/min was proof of mucociliary clearance. In a process of migration starting from the margin of the trachea, the ciliated epithelium pervaded and replaced the preexisting temporary one-layer stratified squamous epithelium. This completely new technique of circumferential tracheal replacement with autogenous cartilage, avoiding permanent incorporation of foreign material, succeeds within the observation period of up to 7 months.     

Experimental reconstruction of the canine trachea with a free revascularized small bowel graft

Extensive tracheal stenotic lesions caused by tracheomalacia or neoplasms represent a surgical challenge. Segmental tracheal substitution is sometimes required to obtain radical cure. We present an experimental study of 27 dogs undergoing replacement of the cervical trachea using a vascularized small bowel segment as a tubular graft. A silicone stent was placed in the lumen of the intestinal fragment and was removed the second week after operation. Endoscopic and histological examinations were performed between the first week and second month after operation, and rigidity of the graft was assessed in all cases. No evidence of anastomotic stricture or mucous formation was found. Microscopic examination showed the substitution of bowel mucosa by squamous epithelium as well as the development of connective tissue favoring the fixation of the skeletal muscular structures of the neck to the serous layer of the graft, thus avoiding collapse of the new airway.     

Prediction of spinal cord ischemia with a retrievable stent graft on endovascular treatment for a case of thoracic aortic aneurysm

Multiple aortic aneurysms in Behçet’s disease were repaired with transluminaly placed endovascular stent grafts. Before deploying the stent graft device for permanent implantation for the saccular aneurysm located in the descending thoracic arota, from which feeding arteries for the spinal cord possibly branched, a retrievable stent graft was inserted and evoked spinal cord potential (ESP) were monitored in order to predict spinal cord ischemia. The original retrievable stent graft, constructed of a self-expandable Z-shaped stainless steel stent covered with e-PTFE, can be easily withdrawn into a 18 Fr. sheath after deployment. Blood flow into intercostal arteries branching from that part of the descending aorta where the permanent stent graft is planned to be implanted, is intercepted by the retrievable stent graft. A change of ESP during the temporary implantation of the device indicates that spinal cord ischemia would be caused by permanent implantation of the stent graft. In this case, no change of ESP was observed and the patient showed no postoperative paraplegia.The retrievable stent graft was useful for prediction of spinal cord ischemia before endoluminal stent graft repair of the descending aortic aneurysm. However, the device is not flexible enough to fit a severely tortuous aorta, therefore we are obliged to select patients to some extent. Further improvement of the device is required to make prediction of spinal cord ischemia with the retrievable stent graft possible in all cases.     

Open stent grafting for complex diseases of the thoracic aorta: clinical utility

Open stent grafting is an alternative treatment for extensive thoracic aortic replacement. However, this procedure is associated with a high incidence of spinal cord injury, which has limited its application. Multiple factors have been suggested to explain the risk of spinal cord injury, including deep delivery of the stent graft, history of operation of the downstream aorta, and postoperative low blood pressure. Cerebrospinal fluid drainage or a hybrid operation in combination with trans-femoral thoracic stent grafting is useful for preventing spinal cord injury. Open stent grafting remains an alternative treatment for atherosclerotic aneurysms with dilatation of the ascending aorta. Open stent grafting for acute aortic dissection is effective for remodeling of the false lumen. The graft diameter for aortic dissection should be 90 % of the total diameter of the aorta, and the distal landing zone should be limited to the T7 vertebral level to prevent new intimal tears or spinal cord injury. Open stent grafting seems a feasible bailout strategy for the treatment of retrograde aortic dissection after TEVAR for type B aortic dissection. Newly designed devices for open stent grafts include the Matsui-Kitamura stent graft or branched open stent graft, which is produced in Japan. The effectiveness of open stent grafting in the treatment of Marfan syndrome remains unclear. A commercially available device for open stent grafting would be desired in Japan. In conclusion, an open stent graft remains an alternative treatment for complex thoracic aortic pathologies.     

Extending hybrid approach to residual Stanford type A dissecting aortic aneurysm

Residual Stanford type A dissecting aortic aneurysm was frequently encountered several years after emergent repair. Surgical approach remained challenging and hazardous, not only due to the extensive involvement of the dilated false lumen but also the high comorbidity of redo sternotomy and extensive thoraco-abdominal procedure. We present a modified hybrid technique incorporating arch replacement with bifurcated graft to relocate supra-aortic branches followed by anastomosis with reverse sleeve graft of elephant trunk over distal arch. After stent graft insertion over proper landing zone, all the communicating holes could be sealed and the compressed true lumen of descending aorta would be fully dilated. This technique not only simplified some laborious situations but also simultaneously resolved the entire thoracic dissection segment with an acceptable and optimal midterm result.     

Extensive primary repair of the thoracic aorta in Stanford type A acute aortic dissection by means of a synthetic vascular graft with a self-expandable stent

OBJECTIVES: To minimize any residual false lumen when operating on patients with an acute type A aortic dissection, we tried to perform extensive primary repair of the thoracic aorta with the modified elephant trunk technique. The early and midterm results of these surgical interventions are reported and evaluated. METHODS: Among the acute type A aortic dissections with extensive false lumen encountered since December 1997, 19 consecutive patients, 15 DeBakey type I with the tear in the ascending, transverse, or both aortas, and 4 DeBakey type III-D with the tear located in the descending aorta, underwent insertion of a synthetic graft with a distally anchored stent in the descending thoracic aorta. The interpolation method was used as an introducer combined with total replacement of the aortic arch by using a synthetic branching graft with only a median sternotomy. RESULTS: One patient died, and 18 were discharged after full recovery. Postoperative computed tomographic scans showed that no residual false lumina were present proximal to the diaphragmatic level, and no false lumina were found in 10 patients. Two patients with acute ischemia of the right kidney caused by narrowing of the true lumen, as demonstrated by radiographic computed tomography, improved significantly after surgical intervention with restoration of blood flow in the true lumen. Paraplegia was not observed in any patient. CONCLUSIONS: In emergency operations for an acute type A aortic dissection, the operation is often limited to replacing the ascending aorta because priority is given to saving the patient's life. However, it is possible to perform extensive primary repair of the thoracic aorta with relative safety by interpolating a synthetic graft with a self-expandable stent.     

Primary aortoesophageal fistula from aortic aneurysm: successful surgical treatment by use of omental pedicle graft

A 65-year-old woman sought treatment for sentinel upper gastrointestinal hemorrhage. Three years previously she had undergone graft replacement of her ascending aorta for aneurysm. In the interim she was followed for chronic dissection of her remaining aorta, and 6 months before this admission she had undergone graft replacement of a large abdominal aortic aneurysm. Arteriography and CT scanning of the thorax revealed an 8 cm aneurysm of the descending thoracic aorta. Operation was undertaken at which time an aortoesophageal fistula, as a result of erosion of the aneurysm into the esophagus, was identified. The descending thoracic aortic aneurysm was replaced with a Dacron tube graft, the esophageal defect was repaired primarily, and a viable pedicle flap of omentum was used to reinforce the esophageal repair and cover the aortic graft. Her postoperative recovery was free of infection but complicated by rapid expansion of the upper abdominal aorta at the visceral arterial level. Eight weeks after initial operation she underwent graft replacement of her remaining thoracoabdominal aorta with direct reattachment of her celiac axis, superior mesenteric artery, and both renal arteries. Recovery after her second procedure was uneventful, and she continues to do well at 13 months after operation. Development of a primary aortoesophageal fistula caused by aneurysms of the aorta is a rare but lethal complication. We present a technique for treatment of primary aortoesophageal fistula using omentum and preservation of gastrointestinal continuity as a one-stage operation. It is possible in selected cases to manage the esophageal perforation with primary closure and omental coverage to achieve healing free of infection without temporary or permanent discontinuity of the gastrointestinal tract.     

Simultaneous repair of arch and abdominal aortic aneurysms

Objective: Atherosclerotic aneurysms in the aortic arch are associated with abdominal aortic aneurysms in up to 37% of cases. We have developed a single-stage approach to the repair of both aneurysms using a temporary bypass. Subjects: Since November 1996, 5 patients underwent simultaneous repair of aneurysms in the aortic arch and in the infrarenal abdominal aorta, using a new temporary bypass graft technique. Entire arch replacement with simultaneous abdominal aortic aneurysmectomy was performed in one patient. The other 4 patients underwent distal hemiarch replacement distal from the orifice of the brachiocephalic artery with simultaneous repair of the abdominal aortic aneurysm. Method: For the entire arch replacement procedure, blood flow to all major branches of the aortic arch was established using a bifurcated graft. This graft anastomosed to the ascending aorta was used as the proximal inflow of the temporary bypass graft. For the hemiarch replacement procedure, the proximal inflow segment of the temporary bypass graft was anastomosed to the brachiocephalic artery. In both cases, the distal outflow segment of the temporary bypass graft was the graft used for repair of the abdominal aortic aneurysm. In order to prevent any clamp injury, Teflon felt was tightly wrapped around the aorta before the clamp was applied. Results: Evaluation of the hemodynamic parameters measured during cross-clamping of the aortic arch revealed stable distal perfusion to the visceral organs and no excessive increase in cardiac afterload. All patients had an uneventful postoperative course and were discharged within 1 month of surgery. Conclusion: Our temporary bypass method is recommended for simultaneous replacement of aneurysms in the aortic arch and the abdominal aorta.     

Successful treatment of an infected thoracic endovascular stent graft

A 70-year-old man with a chronic type B aortic dissection was treated with two stent grafts deployed in the descending thoracic aorta. The patient was re-admitted to the hospital at 16 months after thoracic endovascular stent grafting because of a high fever. A blood culture showed sepsis due to a Staphylococcus species. A CT scan showed an increase in the size of the thrombosed false lumen. Complete excision of the infected descending aortic wall and infected stent graft were performed. The descending thoracic aorta was reconstructed using a rifampicin-bonded Dacron graft and omental wrapping. The combination of in situ graft replacement using a rifampicin-bonded graft and omental wrapping is considered an effective treatment for thoracic stent graft infection.     

Endovascular stent grafting of the descending thoracic aorta after arch repair in acute type A dissection

An endovascular stent graft was successfully deployed to the primary entry site in the proximal descending thoracic aorta after total aortic arch replacement using the "elephant trunk" technique in acute type A aortic dissection. The residual false lumen of the descending aorta was thrombosed completely after stent grafting. The elephant trunk was feasible for a proximal landing zone for stent grafting of the descending aorta. Stent grafting in combination with aortic arch replacement was a safe and effective procedure, and may be an alternative choice in carefully selected patients with type A aortic dissection.     

Simultaneous repair of arch and abdominal aortic aneurysms. A simple new technique using a temporary bypass graft.

OBJECTIVE: Atherosclerotic aneurysms in the aortic arch are associated with abdominal aortic aneurysms in up to 37% of cases. We have developed a single-stage approach to the repair of both aneurysms using a temporary bypass. SUBJECTS: Since November 1996, 5 patients underwent simultaneous repair of aneurysms in the aortic arch and in the infrarenal abdominal aorta, using a new temporary bypass graft technique. Entire arch replacement with simultaneous abdominal aortic aneurysmectomy was performed in one patient. The other 4 patients underwent distal hemi-arch replacement distal from the orifice of the brachiocephalic artery with simultaneous repair of the abdominal aortic aneurysm. METHOD: For the entire arch replacement procedure, blood flow to all major branches of the aortic arch was established using a bifurcated graft. This graft anastomosed to the ascending aorta was used as the proximal inflow of the temporary bypass graft. For the hemi-arch replacement procedure, the proximal inflow segment of the temporary bypass graft was anastomosed to the brachiocephalic artery. In both cases, the distal outflow segment of the temporary bypass graft was the graft used for repair of the abdominal aortic aneurysm. In order to prevent any clamp injury, Teflon felt was tightly wrapped around the aorta before the clamp was applied. RESULTS: Evaluation of the hemodynamic parameters measured during cross-clamping of the aortic arch revealed stable distal perfusion to the visceral organs and no excessive increase in cardiac afterload. All patients had an uneventful postoperative course and were discharged within 1 month of surgery. CONCLUSION: Our temporary bypass method is recommended for simultaneous replacement of aneurysms in the aortic arch and the abdominal aorta.     

Evaluation of spinal cord ischemia in endovascular stent graft repair and surgical operation of descending thoracic or thoracoabdominal aortic aneurysms

Between October 1996 and June 2003, endovascular stent graft repair was performed in 87 patients with descending thoracic aortic aneurysms, graft replacement was performed in 24 patients with thoracoabdominal aortic aneurysms, and endovascular stent graft repair with concomitant surgical bypass of abdominal visceral arteries was performed in 3 patients with thoracoabdominal aortic aneurysms. The retrievable stent graft was inserted and evoked spinal cord potential were monitored in order to predict spinal cord ischemia for stent graft repair. There was no paraplegia or hospital death, although 3 patients had paraparesis in stent graft repair. Two of the 3 patients with paraparesis made a full neurologic recovery. There were no cases of paraplegia or paraparesis in surgical operations with thoracoabdominal aortic aneurysm. The concomitant surgical procedure was a good technique for patients in whom cardiopulmonary bypass could not be used. Our results of stent graft repair and surgical operation for descending thoracic or thoracoabdominal aortic aneurysms were acceptable. The retrievable stent graft was useful for prediction of spinal cord ischemia before endovascular stent graft repair of descending thoracic or thoracoabdominal aortic aneurysm.     

带金属网架小肠移植替代气管的实验研究

用带金属网架游离小肠移植进行犬气管替代。方法采用游离小肠段，外置金属网架，内置硅橡胶管，通过小血管吻合建立血运，替代６ｃｍ长气管。结果气管替代后动物呼吸和活动状况良好，肠管与气管吻合口愈合坚实，病理学检查示肠粘膜层萎缩变薄，吻合口处气管上皮与肠腺上皮连接，未见上度化生及爬行替代现象。结论用带金属网架的游离小肠移植为一可考虑的替代气管方法。     

Repair of the thoracic aorta by transaortic stent grafting (open stenting)

BACKGROUND: The late results of direct open stent grafting of the aortic arch for aortic arch repair have not been reported previously. METHODS: Between September 1997 and December 2000 19 patients underwent open stent grafting with carotid artery bypass for thoracic arteriosclerotic aneurysms (TAA) of the distal aortic arch. In addition, 21 patients underwent open stent grafting with total aortic arch replacement for Stanford type A acute aortic dissection and 7 patients underwent stenting with carotid bypass for Stanford type B chronic aortic dissection. RESULTS: The early mortality rate was 11% for TAA, 10% for type A dissection, and 0% for type B dissection. Whereas none of the TAA or type A dissection required a second operation on the thoracic aorta, 1 TAA patient died 6 months postoperatively after sudden aortic rupture and 1 type B patient required descending aortic replacement because of ulceration caused by the stent graft at 11 months postoperatively. On follow-up computed tomography scan, in TAA patients, true aneurysms excluded by the stent graft showed early thrombosis, but the absorption of thrombosed aneurysms started from 1 to 6 months postoperatively and gradually progressed. In patients with type B chronic dissection, the false lumen showed early thrombosis and the true lumen was dilated at the central portion of the graft, which might increase turbulent flow by interaction with the stent. In patients with type A acute dissection, the false lumen showed both early thrombosis and early absorption. CONCLUSIONS: Early and late results of open stenting are acceptable and follow-up computed tomography scan may be able to predict late results of open stenting.     

Anesthetic management for distal aortic arch aneurysm stent grafting

A 76-year-old woman with thoracic aortic aneurysm involving distal aortic arch was scheduled for graft replacement from ascending to proximal aortic arch with endovascular stent graft to descending aorta. Surgical procedures were performed under median sternotomy with hypothermic systemic circulation arrest and selective cerebral perfusion. The stent graft composed of 30 mm Gianturco Z stent and 27.5 mm woven Dacron graft was introduced into the descending aorta under the guidance of transesophageal echocardiography (TEE) and fluoroscopy. Ascending and proximal aortic arch replacement was then performed with four branched woven Dacron graft. The aortic pathology was confirmed by TEE and the extent of the aneurysmal lesion was defined. TEE was also useful to find the dislodgement of the stent graft after deployment. This surgical technique, being less invasive than conventional thoracotomy, would be indicated for elderly patients with distal aortic arch aneurysm. TEE is the vital imaging technique for placement of the stent graft, as well as for intraoperative cardiac monitoring.     

Aortic operation after previous coronary artery bypass grafting

OBJECTIVES: Aortic surgery for progressive aortic valve disease or aortic aneurysm after previous coronary artery bypass grafting (CABG) is a challenging procedure. We report the outcome of aortic reoperation after previous CABG and evaluate our management of patent grafts and our methods for obtaining myocardial protection. METHODS: From February 2001 to July 2003, 6 patients with progressive aortic valve disease and aneurysm of the thoracic aorta were operated on. The group comprised 3 men and 3 women with a mean age of 67.6 years. There were 4 patients with an aneurysm of the aortic arch, 1 with chronic ascending aortic dissection, and 1 with progressive aortic valve stenosis. The interval between previous CABG and aortic surgery was 74.0 +/- 44.2 months. All reoperations were performed via median resternotomy. Myocardial protection was obtained by hypothermic perfusion of patent in-situ arterial grafts following cold-blood cardioplegia administration via the aortic root under aortic cross clamping. RESULTS: The operative procedure was aortic arch replacement in 4 patients, ascending aortic replacement with double CABG in 1, and aortic valve replacement in 1. All patients survived the reoperation. Postoperative maximum creatine kinase-MB was 49.2 +/- 29.8 and no new Q-waves occurred in the electrocardiogram nor were any new wall motion abnormalities recognized on echocardiography. There were no late deaths during a follow-up of 30.7 months. CONCLUSION: Reoperative aortic procedures after CABG can be performed safely with myocardial protection via hypothermic perfusion of a patent in-situ arterial graft.     

用肺组织瓣重建胸段气管的动物实验与临床应用

目的 探讨用肺组织瓣重建胸段气管的可行性。方法 健康犬15只,切除其长6～8个气管软骨环、周径1／2以上的气管前、后壁,内置镍钛合金网架。游离邻近带血管蒂的肺组织瓣,缝合修补气管壁之缺损。分别于术后2～12个月处死动物,观察气管缺损部位的修复情况,并取材行光学显微镜及电镜检察。临床上用此方法治疗4例患者,其中1例右主支气管因瘢痕狭窄闭锁,1例主气管下段混合瘤恶变,2例左主支气管类癌。结果 实验犬呼吸道通畅、无狭窄及肉芽组织形成,用于修复的肺组织瓣和金属网架表面覆盖有较完整的假复层纤毛柱状上皮。临床治疗的4例患者,均顺利恢复正常呼吸功能,随访疗效稳定。结论 肺组织瓣是较理想的胸段气管重建材料。     

Clinical results of endovascular stent graft repair for fifty cases of thoracic aortic aneurysms

Between February 1995 and December 1997, 50 cases (55 lesions) of thoracic aortic aneurysms including 20 cases of aortic dissections were treated with an endovascular technique using the stent grafts. All patients were treated in the operating room under general anesthesia and the stent grafts were implanted through 18 Fr. or 20 Fr. sheathes via femoral arteries under fluoroscopic guidance. The stent graft was composed of several units of self-expanding stainlesssteel Z stents covered with an ultra-thin polyester fabric. Stent graft deployment was technically successful in 53 of 55 lesions (delivery success rate: 96.4%). Exclusion of the aneurysms and entry closing without endoleak were achieved within two weeks after the operation in 43 of 53 lesions (initial success rate: 81.1%). Endoleak was found in 10 lesions (minor endoleak: 8 and major endoleak: 2 lesions). Two patients died in the periopertive period of delivery failures as injury to external iliac artery and damage to the delivery sheath caused by tortuous and narrow access routes. Endovascular stent graft repair of thoracic aortic aneurysms is minimally invasive operation in comparison with conventional surgical graft replacement with extracorporeal circulation. These early results suggest that the stent graft repair is possibly safe and useful treatment for the patients of thoracic aortic aneurysms especially in high risk patients. However, careful long-term follow-up is necessary to prove the value and the effects of this endovascular treatment and improvement of the stent graft system and technical training of endovascular surgery for operators are required to reduce the delivery failure and to determin the stent graft repair is reliable treatment.     

Surgical correction of failed thoracic endovascular aortic repair

OBJECTIVE: The number of thoracic aortic endovascular procedures is increasing rapidly, and the clinical outcome largely depends on the underlying aortic pathology. When primary stent grafting is unsuccessful, secondary endovascular solutions are most often feasible. However, in recurrent endovascular failure without further minimally invasive options, conservative treatments or conversion to open surgery are the only remaining therapeutic strategies. METHODS: In our experience, 106 patients received thoracic aortic endovascular treatment. Five of these patients and three from other centers underwent conversion to open repair because of 4 type Ia endoleaks (3 thoracic aortic aneurysms, 1 traumatic rupture), 2 retrograde type A dissections, 1 type Ib endoleak with contained rupture, and 1 secondary false aneurysm rupture due to stent graft migration. The latter four were surgical emergencies; the other four were urgent or elective procedures. Three patients underwent supracoronary arch replacement through sternotomy. One patient had arch and proximal descending aortic replacement, three had hemiarch and descending aortic replacement, and one had descending aortic replacement through left thoracotomy. Five stent grafts were totally removed, and three endografts were left in situ. All conversions were performed according to a protocol including total extracorporeal circulation (n = 7) or left heart bypass (n = 1), cerebrospinal fluid drainage and monitoring motor-evoked potentials, transcranial Doppler, and electroencephalography. RESULTS: All patients survived the surgical procedure. Six patients had an uneventful postoperative course, whereas necrotic cholecystitis developed in one patient who required cholecystectomy and prolonged intensive care stay. One polytrauma patient died from secondary rupture due to prosthesis infection 24 days after stent graft explantation. No stroke, paraplegia, renal failure, or other major complication occurred. With a mean follow-up of 14 months (range, 4-71 months), seven patients are alive without any sign of recurrent aortic problems. CONCLUSION: Failure of thoracic endovascular aortic repair comprises a new aortic pathology. Secondary endovascular treatment is feasible in most patients; however, some patients will require open surgery to repair failures of thoracic endovascular aortic treatment. These procedures constitute a large surgical trauma and require an extensive protocol, including extracorporeal circulation, neuromonitoring, and adjunctive modalities to provide organ protection. We recommend that these procedures be performed in centers with experience and the infrastructure to offer these protective measures.