Endovascular stent-grafting for descending thoracic aortic aneurysms.

OBJECTIVE: Endoluminal placement of covered stent-grafts emerges as a less-invasive alternative to open surgical repair of thoracic aortic aneurysms (TAA). The present report describes our experience with endovascular stent-grafting in the treatment of descending TAA. METHODS: From 1997 to 2001, 28 descending TAA's were treated in 27 patients (17 male, mean age 70 years) by endovascular stent-grafting. The aneurysms (mean diameter, 6.6 cm) had diverse causes, but the majority were due to atherosclerosis (71%). They were predominantly localized in the proximal (32%), central (39%), and distal part (22%) of the descending thoracic aorta. In two patients (7%), the entire thoracic aorta was treated. Preliminary subclavian-carotid artery transposition was performed in five patients. AneurX (n=6), Talent (n=9), and Excluder (n=13) stent-grafts were used. In 13 cases (46%), multiple stents were necessary for complete aneurysm exclusion. RESULTS: In 27 of 28 cases (96%), the endovascular stent-grafts were successfully deployed. In one patient, stent dislocation into the aneurysm required open surgical repair in a subsequent procedure. There was no operative mortality. None of the patients developed paraplegia or paraparesis. No distal embolization occurred. After a median follow-up of 21 months (range, 1-49 months), there was one non-related late death. There was no aneurysm rupture. Maximal aneurysm diameter either remained stable or decreased slightly over time in all but one patient with evidence of an endoleak. Endoleaks occurred in eight patients (29%) during follow-up. In five of them the endoleaks sealed spontaneously, whereas in two patients a distal extension was inserted. CONCLUSIONS: Endovascular repair of descending TAA's is a promising less-invasive alternative to open repair. Extended follow-up is necessary to determine its definite efficacy in the longer term.     

Endovascular treatment of descending thoracic aortic aneurysms and dissections.

Various endovascular techniques have become viable therapeutic alternatives in the treatment of patients with many types of descending thoracic aortic pathology and aortic dissections. Descending thoracic aortic aneurysms can be successfully treated using stent grafts. This technique is less invasive and is associated with acceptable morbidity and mortality rates. Patients who are particularly likely to benefit include the very elderly population; those with markedly compromised cardiac, pulmonary, or renal status; and individuals who have previously undergone complex operations on the thoracic aorta. Other endovascular methods, such as aortic flap fenestration, stent, or covering of the primary intimal tear in the descending thoracic aorta with a stent graft, have also been effectively employed in the treatment of peripheral arterial complications of aortic dissection. Despite the reported early success of these endovascular percutaneous methods, true assessment of the effectiveness of these various techniques awaits long-term follow-up evaluation in large patient populations.     

Natural history of descending thoracic and thoracoabdominal aortic aneurysms

ObjectivesElucidating critical aortic diameters at which natural complications (rupture, dissection, and death) occur is of paramount importance to guide timely surgical intervention. Natural history knowledge for descending thoracic and thoracoabdominal aortic aneurysms is sparse. Our small early studies recommended repairing descending thoracic and thoracoabdominal aortic aneurysms before a critical diameter of 7.0 cm. We focus exclusively on a large number of descending thoracic and thoracoabdominal aortic aneurysms followed over time, enabling a more detailed analysis with greater granularity across aortic sizes.MethodsAortic diameters and long-term complications of 907 patients with descending thoracic and thoracoabdominal aortic aneurysms were reviewed. Growth rates (instrumental variables approach), yearly complication rates, 5-year event-free survival (Kaplan–Meier), and risk of complications as a function of aortic height index (aortic diameter [centimeters]/height [meters]) (competing-risks regression) were calculated.ResultsEstimated mean growth rate of descending thoracic and thoracoabdominal aortic aneurysms was 0.19 cm/year, increasing with increasing aortic size. Median size at acute type B dissection was 4.1 cm. Some 80% of dissections occurred below 5 cm, whereas 93% of ruptures occurred above 5 cm. Descending thoracic and thoracoabdominal aortic aneurysm diameter 6 cm or greater was associated with a 19% yearly rate of rupture, dissection, or death. Five-year complication-free survival progressively decreased with increasing aortic height index. Hazard of complications showed a 6-fold increase at an aortic height index of 4.2 or greater compared with an aortic height index of 3.0 to 3.5 (P < .05). The probability of fatal complications (aortic rupture or death) increased sharply at 2 hinge points: 6.0 and 6.5 cm.ConclusionsAcute type B dissections occur frequently at small aortic sizes; thus, prophylactic size-based surgery may not afford a means for dissection protection. However, fatal complications increase dramatically at 6.0 cm, suggesting that preemptive intervention before that criterion can save lives.     

Repair of descending thoracic aortic aneurysms with Ankura Thoracic Stent Graft

Objective

The aim of the study was to present the results for patients with atherosclerotic aneurysm of the descending thoracic aorta (DTA) treated with a novel thoracic stent graft.

Endoluminal versus open treatment of descending thoracic aortic aneurysms

PURPOSE: This report describes the authors' initial experience with the Excluder thoracic endoprosthesis (W. L. Gore and Associates, Inc, Flagstaff, Ariz) and the thoracic Talent endoprosthesis (Medtronic AVE, Sunrise, Fla) and their safety and efficacy in the primary endovascular repair of descending thoracic aortic aneurysms (TAAs). In addition, comparison with a historic nonrandomized cohort of patients that had undergone open repair of descending TAAs is reported. PATIENTS AND METHODS: Repair of TAA (mean diameter, 68 +/- 22 mm) was attempted in 19 patients with the Excluder (n = 14) and the Talent (n = 5) endoprostheses between March 1999 and January 2000. This group was compared with a historic nonrandomized cohort of 10 patients that had undergone open repair of anatomically similar descending TAA (mean diameter, 74 +/- 22 mm) between January 1996 and January 1998. The mean age in the endovascular group was 70.6 +/- 5.3 years versus 70.1 +/- 4.5 years in the historic open group. All the procedures were performed in a standard operating room with angiographic capabilities. In the historic open group, each standard tube graft repair of descending TAA was performed by one of three staff surgeons. RESULTS: Endograft deployment was successful in 18 patients (95%). The procedure was aborted in one patient (Excluder) because of small iliac arteries and access difficulty. The average operative time was 155 +/- 62 minutes, with a mean blood loss of 325 +/- 353 mL (versus 256 +/- 102 minutes and 1205 +/- 1493 mL, respectively, in the open group). Eight patients needed the planned use of more than one component for enhanced sealing or additional length in the endovascular group. No type I endoleaks were identified on the intraoperative completion angiography. One perioperative mortality occurred in the endovascular group and the open group. In the endovascular group, other complications included retroperitoneal hematoma and external iliac artery dissection (n = 1), lymphocele (n = 1), and common femoral artery pseudoaneurysm (n = 1). In the open group, other complications included ischemic colitis (n = 1), severe renal insufficiency (n = 2), wound infection (n = 1), and stroke (n = 1). In the endovascular group, the length of stay was 6.2 +/- 3.3 days (range, 1 to 13 days), with only nine patients needing intensive care, whereas in the open group, the length of stay was 16.3 +/- 6.7 days, with all patients needing intensive care. Endoleaks, graft migrations, or ruptures were not seen on the 1-month, 6-month, and 12-month follow-up computed tomographic scans in the endovascular group. On the average, aneurysm size decreased from 68 +/- 22 mm to 58 +/- 13 mm, to 51 +/- 14 mm, and to 49 +/- 12 mm at 1, 6, and 12 months after endovascular repair, respectively. No spinal cord ischemia was seen in either group. CONCLUSION: The endoluminal repair was effective in exclusion of descending TAAs from the systemic circulation in this selected group of patients. In this short-term follow-up, compared with the nonrandomized historic cohort of open descending TAA repair, the endovascular group had significantly shorter operating times and hospital and intensive care unit stays and lower operative blood loss. Further follow-up and continued assessment of the long-term durability of these devices in elective and emergency circumstances are warranted.     

Surgical correction of descending thoracic aortic aneurysms under simple aortic cross-clamping

Between June 1983 and December 1987, 52 patients underwent resection of a descending thoracic aortic aneurysm under simple aortic cross-clamping without the use of shunting or bypass techniques. The 30-day mortality rate was 11.5%; 4.8% for elective cases and 36.5% for patients operated on in emergency. Two patients (4%) had spinal cord injury. One patient had paraplegia, and the other had mild paraparesis but completely recovered. Both patients were operated on for ruptured aneurysms. Four patients (7.5%) had severe postoperative renal dysfunction that was strongly related to intraoperative hypotension. The cumulative proportional survival rate was 81% at 1 year and 66% at 2 years for the total group. 85% at 1 year and 72% at 2 years for the patients first seen with nonruptured aneurysms. Aneurysms of the descending thoracic aorta can be safely resected without the use of shunting or bypass techniques. Surgery definitely improves the outcome for these patients who have a poor prognosis if left untreated.     

Nitroglycerin to control blood pressure during endovascular stent-grafting of descending thoracic aortic aneurysms

Temporary asystole induced with adenosine or electrically induced ventricular fibrillation has previously been proposed to prevent hypertension during transluminal placement of thoracic endovascular stent-grafts. Nitroglycerin is a safe and less invasive alternative to control blood pressure and, in contrast to the methods mentioned, can also be used during stent-grafting performed under local anesthesia.     

Cardiotomy suction versus red cell spinning during repair of descending thoracic aortic aneurysms

Two consecutive series of patients undergoing repair of descending thoracic and thoracoabdominal aortic aneurysms with partial cardiopulmonary bypass and low systemic heparinization (activated coagulation time: ACT greater than 180 sec) for proximal unloading and distal protection were analyzed. During the surgical procedures, thoracic shed blood was recovered either with a red cell spinning autotransfusion device (n=10) or two pump suckers and Duraflo II heparin surface coated cardiotomy reservoirs (n=10). There were 5/10 acute lesions and 1/10 ruptures for the autotransfusion group versus 5/10 acute lesions and 2/10 ruptures for the cardiotomy group (NS). Extension of aortic resection (range 1-8) was 3.6+/-1.2 for autotransfusion versus 3.5+/-1.4 for cardiotomy suction (NS). Mean number of reimplanted patches for intercostal and visceral reperfusion was 0.3+/-0.6 for autotransfusion versus 0.6+/-1.0 for cardiotomy (NS). Perfusion time was 41+/-17 min for autotransfusion versus 60+/-19 min for cardiotomy (p less than 0.05) and cross clamp time was 33+/-14 min for autotransfusion versus 43+/-17 min for cardiotomy (p less than 0.01). Total heparin dose was for 9500+/-2100 IU for autotransfusion versus 9800+/-1300 IU for cardiotomy (NS). The mean of the lowest ACTs measured during perfusion was 281+/-121 sec for autotransfusion versus 258+/-58 sec for cardiotomy (NS). The total protamine dose given was 7800+/-2100 IU for autotransfusion versus 9700+/-1900 IU for cardiotomy (p less than 0.05). The volume of washed red cells prepared was 3186+/-1318 ml for autotransfusion versus 0 for cardiotomy (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Extracorporeal circulation with low systemic heparinization during lung transplantation

BACKGROUND: Some lung transplantation (LT) recipients suffer from pulmonary hypertension and right ventricular dysfunction or failure requiring extracorporeal circulation (ECC) to avoid catastrophic complications during surgery. The extracorporeal support usually requires systemic heparinization which is potentially associated with important side effects. We performed eight LT using preheparinized ECC circuits and an oxygenator associated with a lower level of systemic heparinization without evidence of perioperative complications. PATIENTS AND METHODS: From May 2002 to May 2005, 8 patients (5 men and 3 women) of mean age 22.5 +/- 9.5 years underwent bilateral sequential lung transplantation (BSLT) for cystic fibrosis (n = 6) or idiopathic pulmonary fibrosis (n = 2). All procedures were performed with ECC through a femoro-femoral veno-arterial bypass with preheparinized circuits and an oxygenator. RESULTS: No intraoperative mortality occurred. The mean ECC time was 147.8 +/- 31.3 minutes and the mean heparin administered was 3525 +/- 969.16 UI. No coagulopathy or thrombotic events were observed perioperatively. CONCLUSIONS: Our study confirmed the efficacy and safety of prehepanized circuits and oxygenator for femoro-femoral veno-arterial bypass during LT for patients with severe pulmonary hypertension requiring ECC.     

Long-term results of endovascular repair for descending thoracic aortic aneurysms

Objective

Since thoracic endovascular aortic repair (TEVAR) received U.S. Food and Drug Administration approval for the treatment of descending thoracic aneurysms in March 2005, excellent 30-day and midterm outcomes have been described. However, data on long-term outcomes are lacking with Medicare data suggesting that TEVAR has worse late survival compared with open descending repair. As such, the purpose of this study was to examine the long-term outcomes for on-label use of TEVAR for repair of descending thoracic aneurysms.

Long-term results of endoluminal grafting for descending thoracic aortic aneurysms

Objective: This paper describes the long-term results of endoluminal grafting (EG) for the treatment of descending thoracic aortic aneurysms (dTAA). Methods: Until July 2004, EG for dTAA has been applied in 45 cases (male/female, 29/16, 49–86 years old, mean age 67 years old). Locations included the proximal dTAA in 24 cases, and middle or distal dTAA in 21 cases. The stent-grafts (SGs) were constructed of Gianturco Z-stents covered with woven polyester grafts. Results: Deployment of the SGs was successful in 43 of 45 cases (96%) and complete thrombosis of the aneurysm was achieved in 39 cases (87%). Six minor endoleaks (13%), one migration (2%) and one conversion to surgery (2%) occurred. There was no instance of paraplegia nor hospital death. Over a mean 48 month follow-up (range 3 to 90), there were three persistent endoleaks (6%), four secondary endoleaks (8%), one breakage of wire frame (2%). Four cases were converted to open surgery due to secondary endoleak. There were two aneurysmal ruptures at the site where EG was not performed. The cumulative survival rate was 95.6±4.4% at 12 months, 85.7±5.4% at 24 months, and 82.4±6.1% at 36 and 60 months. Conclusion: These results demonstrated that EG is safe and effective in selected dTAA patients. Improvements in patients selection, surgical techniques and equipment will reduce EG related complications and conversion to open repair over the course of the evaluation.     

Hybrid procedure for combined descending thoracic and abdominal aortic aneurysms

In patients with previous infrarenal abdominal aortic aneurysm (AAA) repair, the risk of spinal cord ischemia increases after thoracic endovascular aortic repair (TEVAR) for a descending thoracic aortic aneurysm (DTAA). The case is a 67-year-old man with a 60 mm infrarenal AAA and a 73 mm DTAA. We performed the staged hybrid procedure for these aortic aneurysms. First of all we underwent a conventional AAA repair. The bilateral internal iliac arteries and a inferior mesenteric artery were preserved. In addition, the right leg of the tube graft was anastomosed to the right superficial femoral artery to facilitate access of TEVAR. Two months later we performed TEVAR for the DTAA. DTAA extended from the level of the 7th thoracic vertebra to that of the 11th thoracic vertebra. Although there was a certain risk of paraplegia, no complications occurred. The hybrid procedure for combined DTAA and AAA may be a valuable option.     

Dissecting descending thoracic and thoracoabdominal aortic aneurysms: Part II

Editor's note : Readers will note that there is some overlap in the information presented between this report and the article on aortic dissection by Drs. Fann and Miller, which appeared in this section in the May 1995 issue ofAnnals of Vascular Surgery. This second article on thoracoabdominal aneurysms by Drs. Panneton and Hollier is published because it focuses specifically on the subject of descending thoracic and thoracoabdominal dissections, those most frequently encountered by practicing vascular surgeons. Despite the duplication, the additional information was thought to be worthy of publication.Dr. Panneton is the recipient of the R.S. McLaughlin Foundation Fellowship.     

Technique of open distal anastomosis for repair of descending thoracic aortic aneurysms.

Ischemic injury to the spinal cord and kidneys continues to be the major complication after resection of aneurysms involving the descending and proximal abdominal aorta. Our recent surgical experience with use of only a proximal clamp on the aorta to perform an "open" distal anastomosis has proved this technique to be safe and expeditious. We therefore compared our results using the technique of open distal anastomosis for aneurysm repair with those of the conventional two-clamp technique. Since January 1989, we have used the conventional two-clamp technique in 31 patients (group 1) and the technique of open distal anastomosis in 24 patients (group 2). No significant differences were noted between the two groups in terms of age, sex, cause of aneurysm, extent of aneurysm, or site of proximal cross-clamp. The average distal ischemic time was 31 minutes in group 1 patients and 26 minutes in group 2 patients. Renal insufficiency occurred in 8 of 31 patients in group 1 and in 0 of 24 patients in group 2 (p = 0.01). Neurologic complications occurred in 4 patients in group 1 and in 1 patient in group 2. Early mortality rates were similar for both groups (4 of 31 [13%], group 1; 4 of 24 [17%], group 2). Deaths were attributed to multiorgan failure and sepsis in 6 patients and coexisting coronary artery disease in 2 patients. Based on these results, we believe the technique of open distal anastomosis is safe and may improve the outcome in patients undergoing operation for descending thoracic aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)     

General moderate hypothermia in the surgical treatment of descending thoracic aortic aneurysms.

The diagnosis and surgical treatment of aneurysms of the descending thoracic aorta is difficult and some aspects of management remain controversial. We report 53 patients treated in the period 1983-1988; 25.9% of them had previously been erroneously diagnosed as having mediastinal cysts or tumours. Duplex scanning and computerised tomography were valuable adjuncts in establishing the correct diagnosis, which was confirmed by aortography in 52 patients. Of 49 patients operated upon electively three died with a mortality rate of 6.1%; of the 4 patients operated upon as emergencies 2 died. Fifty patients survived the operative procedure and of the 3 operated upon under normothermia 1 developed paraplegia, whereas of the 47 patients operated upon under moderate hypothermia (30 degrees-31 degrees C) only 1 developed paraplegia.     

Contemporary results of open surgical repair of descending thoracic aortic aneurysms

Considerable progress has been made in the refinement of operative strategies to repair descending thoracic aortic aneurysms (TAA). While no single strategy has totally eliminated the postoperative morbidities of renovisceral and spinal cord ischemic complications, contemporary reports from centers of excellence detail admirable rates of overall risk in the 5-10% range. Balancing these risks represents a clinical dilemma for the aortic surgeon and a thoughtful, logical risk analysis of the individual patient presentation is clearly warranted before TAA repair. In this article, we review surgical approaches to TAA and adjunctive methods, examine the reports from centers of excellence, and elucidate the challenges yet to be overcome in the management of patients with aneurysms of the descending thoracic aorta.     

Optimal methods of repair of descending thoracic aortic transections and aneurysms

The method for optimal protection of the spinal cord and viscera during surgical repair of aneurysms and acute disruptions of the descending thoracic aorta is controversial. We reviewed our experience with 50 consecutive patients who underwent such repairs between January 1968 and April 1982 to determine the safest method of protection. Thirty-two had acute transections, 9 had ruptured aneurysms, 6 had false aneurysms, and three had atherosclerotic aneurysms. Extracorporeal circulation was used in 21 patients with an average cross-clamp time of 67 minutes, a Gott shunt was used in 26 with an average cross-clamp time of 74 minutes, and no shunt was used in 3 patients with cross-clamp times of 20, 24, and 50 minutes. Paraplegia was significantly reduced with both extracorporeal circulation and the heparin-bonded Gott shunt; however, the former method was associated with a high incidence of postoperative bleeding in conjunction with systemic heparinization, and this, in turn, contributed to a high mortality, particularly in patients with traumatic transection who often had associated severe injuries. We believe that the Gott shunt provides the best protection, particularly in the setting of a training program where a relatively small number of these operations are performed and cross-clamp times may be prolonged.     

Saccular descending thoracic aortic aneurysm with dysphagia.

A 76 year old woman had suffered from chest pain, back pain, and dysphagia for 8 months. She was diagnosed as having a thoracic aortic aneurysm by chest X-ray and chest enhanced computed tomography. Simultaneously, severe dysphagia developed. Chest enhanced computed tomography and chest aortic aortography at our hospital demonstrated a saccular descending thoracic aortic aneurysm. Esophagography demonstrated that the esophagus was compressed by the aneurysm; therefore, a graft replacement for the saccular descending thoracic aortic aneurysm was performed on February 17th, 1998. A left sided 6th intercostal approach was made, and graft replacement for the aneurysm using a 22 mm Hemashield prosthetic graft was performed under temporary bypass from the thoracic aorta just distal to the left subclavian artery and to the left femoral artery. The postoperative course was uneventful, the severe dysphagia improved dramatically, but a pleural effusion of 1000 ml collected 3 weeks after the operation. Surgical cases of saccular descending thoracic aortic aneurysm with dysphagia are rare, and with this in mind, we report this case to the the medical literature.