Adenosine-induced ventricular asystole to induce transient profound systemic hypotension in patients undergoing endovascular therapy. Dose-response characteristics

BACKGROUND: Adenosine-induced asystole has been used to induce transient systemic hypotension for various vascular procedures. Dose-response characteristics of adenosine-induced ventricular asystole have not been determined. METHODS: During endovascular embolization of cerebral arteriovenous malformations, the authors performed a series of adenosine test injections to establish a dose-response relation in each patient. After an interval of 3-10 min, the dose was escalated by 10-20 mg for each injection to achieve an end point of 20-30 s of stable mean arterial pressure (MAP) reduction to 25-30 mmHg. All patients received constant infusion of nitroprusside (approximately 1 microgram. kg-1. min-1) throughout the procedure. RESULTS: The authors studied four adult patients (age, 22-44 yr; two patients had two separate procedures) and one pediatric patient (age, 4 yr). Twenty-three adenosine injections resulted in measurable asystole. The adenosine dose was 0. 98 +/- 0.40 mg/kg (mean +/- SD), and the dose range was 0.24-1.76 mg/kg (6-90 mg). The duration of asystole, MAP < 30 mmHg, and MAP < 50 mmHg, were 8 +/- 3 s, 18 +/- 12 s, and 50 +/- 29 s, respectively. The minimum MAP and the MAP for the first 20 s were 16 +/- 3 mmHg and 30 +/- 9 mmHg, respectively. There was a linear relation between adenosine dose and the duration of hypotension with MAP < 30 mmHg and MAP < 50 mmHg. CONCLUSIONS: In the dose range studied, a series of adenosine test injections can be used to determine optimal adenosine dose for induction of transient profound hypotension.     

Adenosine-induced Ventricular Asystole to Induce Transient Profound Systemic Hypotension in Patients Undergoing Endovascular Therapy: Dose-Response Characteristics

Background: Adenosine-induced asystole has been used to induce transient systemic hypotension for various vascular procedures. Dose-response characteristics of adenosine-induced ventricular asystole have not been determined.

Methods: During endovascular embolization of cerebral arteriovenous malformations, the authors performed a series of adenosine test injections to establish a dose-response relation in each patient. After an interval of 3-10 min, the dose was escalated by 10-20 mg for each injection to achieve an end point of 20-30 s of stable mean arterial pressure (MAP) reduction to 25-30 mmHg. All patients received constant infusion of nitroprusside ([almost equal to] 1 [mu]g [middle dot] kg-1 [middle dot] min-1) throughout the procedure.

Results: The authors studied four adult patients (age, 22-44 yr; two patients had two separate procedures) and one pediatric patient (age, 4 yr). Twenty-three adenosine injections resulted in measurable asystole. The adenosine dose was 0.98 +/- 0.40 mg/kg (mean +/- SD), and the dose range was 0.24-1.76 mg/kg (6-90 mg). The duration of asystole, MAP < 30 mmHg, and MAP < 50 mmHg, were 8 +/- 3 s, 18 +/- 12 s, and 50 +/- 29 s, respectively. The minimum MAP and the MAP for the first 20 s were 16 +/- 3 mmHg and 30 +/- 9 mmHg, respectively. There was a linear relation between adenosine dose and the duration of hypotension with MAP < 30 mmHg and MAP < 50 mmHg.     

Asystole during electroconvulsive therapy

BACKGROUND: Asystole during electroconvulsive therapy (ECT) has been reported as an uncommon but fatal complication. But cardiac movement during electrical stimulation has not been well known. METHODS: The cardiac movements during electrical stimulation of fifty psychiatric patients treated by ECT under general anesthesia were observed utilizing thoracic echocardiography. Observations of 117 times were performed. Rate pressure products (RPP) immediately before stimulation and during 10 minutes after stimulation were calculated. Asystole was defined as absence of heartbeat for over 2 seconds. RESULTS: Asystoles were observed 57 times (48.7%). The heartbeat recovered immediately after stimulation in all asystole cases. RPP increased just after stimulation in all cases. Asystole cases had significantly greater variation of RPP than cases without aystole. (P = 0.0082). CONCLUSIONS: Electrical stimulation by ECT activates parasympathetic nervous system and convulsion by the stimulation activates sympathetic nervous system. As asystole case had good reactive automatic nervous system, asystole might have been provoked by the stimulation with a greater increase in RPP after the stimulation.     

Intentional asystole during endoluminal thoracic aortic surgery without cardiopulmonary bypass

We describe in three patients the use of adenosine to arrest the heart without cardiopulmonary bypass during endoluminal repair of thoracic aortic aneurysms. The pharmacology of adenosine, a purine nucleoside present in all cells, is reviewed briefly, with special reference to its use in causing transient asystole, which is required for successful surgical expansion of the graft stent in the thoracic aorta.      

Coverage of the left subclavian artery during thoracic endovascular aortic repair

BACKGROUND: Thoracic aortic stent grafts require proximal and distal landing zones of adequate length to effectively exclude thoracic aortic lesions. The origins of the left subclavian artery and other aortic arch branch vessels often impose limitations on the proximal landing zone, thereby disallowing endovascular repair of more proximal thoracic lesions. METHODS: Between October 2000 and November 2005, 112 patients received stent grafts to treat lesions involving the thoracic aorta. The proximal aspect of the stent graft partially or totally occluded the origin of at least one great vessel in 28 patients (25%). The proximal attachment site was in zone 0 in one patient (3.6%), zone 1 in three patients (10.7%), and zone 2 in 24 patients (85.7%). Patients with proximal implantation in zones 0 or 1 underwent debranching procedures of the supra-aortic vessels before stent graft repair. In one patient who underwent zone 1 deployment, the left subclavian artery was revascularized before stent graft deployment. Among patients who underwent zone 2 deployment with partial or complete occlusion of the left subclavian artery, none underwent prior revascularization. Patients were assessed postoperatively and at follow-up for development of neurologic symptoms as well as symptoms of left upper extremity claudication or ischemia. RESULTS: Mean follow-up was 7.3 months. Among the 24 patients with zone 2 implantation, 10 (42%) had partial left subclavian artery coverage at the time of their primary procedure. A total of 19 patients experienced complete cessation of antegrade flow through the origin of the left subclavian artery without revascularization at the time of the initial endograft repair as a result of a secondary procedure or as a consequence of left subclavian artery thrombosis. Left upper extremity symptoms developed in three (15.8%) patients that did not warrant intervention, and rest pain developed in one (5.3%), which was treated with the deployment of a left subclavian artery stent. Two primary (type IA and type III) endoleaks (7.1%) and one secondary endoleak (type IA) (3.6%) were observed in patients who underwent zone 2 deployment. Three cerebrovascular accidents were observed. Thoracic aortic lesions were successfully excluded in all patients who underwent supra-aortic debranching procedures. CONCLUSION: Intentional coverage of the origin of the left subclavian artery to obtain an adequate proximal landing zone during endovascular repair of thoracic aortic lesions is well tolerated and may be managed expectantly, with some exceptions.     

Endovascular treatment of the descending thoracic aorta.

OBJECTIVES: to report our initial experience with endovascular stent graft repair of a variety of thoracic aortic pathology. DESIGN: retrospective single center study. MATERIAL AND METHODS: between February 2000 and January 2002, endovascular stent graft repair was performed in 26 patients: traumatic aortic isthmus rupture (n=3), Type B dissection (n=11) and descending thoracic aortic aneurysm (n=12). The deployed stent graft systems were AneuRx-Medtronic (n=1), Talent-Medtronic (n=13) and Excluder-Gore (n=12). RESULTS: successful deployment of the stent grafts in the intended position was achieved in all patients. No hospital mortality neither paraplegia were observed. Late, non procedure related, death occurred in four patients (15%). Access artery complications with rupture of the iliac artery occurred in two patients and were managed by iliac-femoral bypass. The left subclavian artery was overstented in seven patients (27%). Only the first patient received a carotido-subclavian bypass. The mean maximal aortic diameter decreased significantly in patients treated for descending thoracic aneurysm. Only one patient had an endoleak type II after 6 months without enlargement of the aneurysm. Complete thrombosis of the thoracic false lumen occurred in all but one patient treated for Type B dissection 6 months postoperatively. Two patients underwent a consecutive stent graft placement, due to a large re-entry tear distal to the first stent graft. CONCLUSIONS: endovascular stent graft repair for Type B dissection, descending thoracic aneurysm and aortic isthmus rupture is a promising less-invasive alternative to surgical repair. Further studies are mandatory to determine its long-term efficacy.     

Endovascular stent grafts and aortic rupture: a case series

BACKGROUND: Endovascular stent grafts (EVSGs) offer an alternative in the management of traumatic rupture of the aorta, particularly in patients who are at prohibitive operative risk. METHODS: We conducted a retrospective review of 11 cases managed by EVSGs over a 4-year period. EVSGs were defined as "noncommercial" (graft material hand sewn over metallic stents) or "commercial" (grafts marketed for infrarenal aortic or thoracic aneurysms). Data collected included the difference between endovascular stent graft length, tear length (apposition length), and location relative to the left subclavian artery. RESULTS: EVSGs (three noncommercial and eight commercial, including AneuRx cuff [six], Talent [one], and Ancure aortic tube graft [one]) were used in 11 patients. Six were placed less than or equal to 8 hours from injury, one after 14 hours, three after 5 days, and one 10 years after injury. Routes of access included femoral (four), iliac (three), and abdominal aorta (four). Average landing zone diameter was 18.8 +/- 3.5 mm, distance from the left subclavian artery was 2.85 +/- 2.1 cm, and tear length was 1.54 +/- 1.0 cm. In four cases, the apposition length was less than 2 cm. There were two cases of persistent endoleak and two cases of endoleak noted and treated at deployment. Persistent endoleak occurred in two of three noncommercial EVSGs. Endoleak occurred in three of four cases when apposition length was less than 2 cm, one of which was treated successfully at the time of placement by deploying extension grafts. Endoleak occurred in two of six cases when deployment was within 2 cm of the origin of the left subclavian artery. In one case of persistent endoleak, open repair was performed 3 weeks later when the patient had stabilized. Ultimately, there were three deaths, two caused by severe closed head injury and one caused by respiratory failure. CONCLUSION: Endovascular stent grafts can be placed emergently. Commercial grafts result in better results than noncommercial grafts. Available "cuff extenders" are sufficient for the majority of aortic injuries but often require deployment via the iliac or aorta because of the shorter delivery system. Tears more than 1.5 cm resulting in apposition length less than 2 cm or those near or in the curvature of the aorta are associated with increased endoleak risk. The ideal thoracic EVSG would be available in 5-, 7.5-, 10-, and 15-cm lengths and mounted on a system 80 cm in length.     

ATP-induced ventricular asystole and hypotension during endovascular stenting surgery

Purpose

To describe four cases of endoluminal stenting surgery in which adenosine 5′-triphosphate (ATP) was used to arrest the heart for accurate placement of the stent-graft.

Clinical features

Four patients with descending thoracic aortic aneurysm were anaesthetized for deployment of a self-expanding stent-graft. Maintenance of general anaesthesia was performed with isoflurane and nitrous oxide in three patients, and with fentanyl and propofol in another. An initial trial of 20 mg ATP was administered via a central venous catheter as rapidly as possible, and produced third degree AV block of 8 ± 1.7 sec and 59.7 ± 17.5 sec: hypotension, mean blood pressure < 60 mmHg, in three patients. The time to onset of AV block was 15.7 ± 6.7 sec. In these patients, deployment of the stent-graft was performed during ventricular asystole produced by 30 mg ATP, which produced 16.3 ± 2.1 sec third and second degree AV block. In one patient anaesthetized with fentanyl and propofol, 20 mg ATP did not change AV conduction. However, after 10 mg edrophonium, 20 mg ATP produced 9 sec third degree AV block. In all cases, heart rate and PQ interval were restored to the pre-drug control level within 50 sec after the commencement of AV block. There were no clinical complications related to this procedure in any patient.

Conclusion

ATP is a convenient and suitable agent to produce transient ventricular asystole for the precise deployment of a self-expanding stent-graft. Co-administration of a parasympathomimetic agent might potentiate the inhibitory effect of ATP on AV conduction.     

Transesophageal echocardiography guidance for stent-graft repair of a thoracic aneurysm is facilitated by the ability of partial stent deployment

Transesophageal echocardiography (TEE) is routinely used in our Institution for monitoring correct positioning of thoracic aortic stent grafts. We present a case of successful endovascular repair of three discrete thoracic aortic aneurysms with Zenith TX2 endovascular stent grafts in an 82-year-old female patient. Our focus is on the increased value of TEE guidance because of the ability of partial stent deployment and manipulation during insertion.     

Thoracic aortic aneurysms: treatment with endovascular self-expandable stent grafts

BACKGROUND: This study was performed to evaluate the safety and feasibility of endovascular stent graft placement in the treatment of descending thoracic aortic aneurysms. METHODS: Between November 1996 and February 1999, endovascular stent graft repair was used in 21 patients. There were 5 women and 16 men with a mean age of 67 years (range, 41 to 87 years). An atherosclerotic aneurysm with a diameter of more than 6 cm was the indication for intervention in 19 patients (90.5%). In 2 patients (9.5%), a localized aortic dissection with a diameter of more than 6 cm was treated. In 71.4% (15 of 21) of patients, multiple stents were necessary for aneurysm exclusion. To allow safe deployment of the stent graft, preliminary subclavian-carotid artery transposition was performed in 9 patients (42.9%). Vascular access was achieved through a small incision in the abdominal aorta (n = 6), an iliac artery (n = 8), or a femoral artery (n = 7). Talent and Prograft stent grafts were used. RESULTS: Successful deployment of the endovascular stent grafts was achieved in all patients. Two patients died postoperatively (mortality rate, 9.5%), 1 of aneurysmal rupture and the other of impaired perfusion of the celiac axis. Repeat stenting was done in 3 patients because of intraoperative leakage. CONCLUSIONS: Endovascular stent graft repair is a promising and less invasive alternative to exclude the aneurysm from blood flow. This technique allows treatment of patients who are unsuitable for conventional surgical procedures. An exact definition of inclusion criteria and technical development of stent grafts should contribute to further improvements in clinical results.     

Postoperative changes in the coagulation and fibrinolytic systems in endoluminal stent-graft treatment of thoracic aortic aneurysms

We studied changes in blood coagulation and fibrinolytic system in 18 cases of thoracic aortic aneurysm and 5 cases of aortic dissection treated with stent grafts. The mean operation time was 259 ± 67 minutes and the amount of blood loss during operation was 472 ± 456 ml. Although blood transfusion of 220 ± 360 ml was performed in 7 cases, 16 of 23 cases (70%) received no homologous blood transfusion. Consequently, the endoluminal stent graft treatment was minimally invasive compared with the conventional surgical procedure. On the 1st postoperative day, platelet counts and AT-III decreased and TAT increased. The promotion of blood coagulability was found in these patients on the 1st day after the operation. Changes in the fibrinolytic system were less marked than that in coagulation. These results suggest that the thrombosed aneurysm was excluded from systemic blood flow by the stent graft. There was no consumption coagulopathy in any case with aneurysm excluded by stent graft deployment. Stent-graft treatment for thoracic aortic aneurysm can be successfully performed without consumption coagulopathy when the aneurysm is completely excluded.     

High thoracic epidural anesthesia as the sole anesthetic for performing multiple grafts in off-pump coronary artery bypass surgery

OBJECTIVES: The feasibility of the use of high thoracic epidural anesthesia as a sole anesthetic in patients undergoing beating heart coronary revascularization avoiding general anesthesia was studied. DESIGN: A prospective study. SETTING: A tertiary care medical center. INTERVENTIONS: Fifteen patients underwent beating heart coronary artery revascularization without endotracheal general anesthesia, between October 2001 to May 2002, using high thoracic epidural anesthesia and analgesia. All the patients underwent epidural catheterization on the evening before the surgery. MEASUREMENTS AND MAIN RESULTS: The patients received 36 grafts (single, n = 5; double, n = 3; triple, n = 3; quadruple, n = 4). There were 3 female patients and 12 male patients with mean age of 60.6 +/- 5.9 years. Two patients underwent repeat coronary artery bypass. All the patients underwent off-pump coronary artery bypass graft surgery; 2 patients underwent grafting via left thoracotomy and the rest through a midsternotomy. There was no conversion to general anesthesia or cardiopulmonary bypass, and there was no mortality. Mean length of stay in the intensive care unit was 18.2 +/- 4.2 hours and in the hospital was 3.2 +/- 1.2 days. CONCLUSION: Experience confirms the feasibility of performing multiple coronary artery bypasses in conscious patients without endotracheal general anesthesia.     

Mid-term results for second-generation thoracic stent grafts

BACKGROUND: Thoracic stent grafts offer an alternative to open surgery for thoracic aortic disease, but their long-term durability is unknown. This report includes mid-term follow-up for commercially available thoracic devices. METHODS: Data were collected prospectively for a series of endoluminal grafts used to treat thoracic aortic pathology. RESULTS: Between July 1997 and October 2002, 67 patients received thoracic stent grafts. Elective procedures incurred a 30-day mortality rate of 2 per cent (one of 42 patients) and urgent repair 16 per cent (four of 25). Paraplegia affected three (4 per cent) of 67 patients and three patients had a stroke. The median follow-up was 17 (range 2-64) months; four patients were lost. There were six late deaths, two from aneurysm rupture (rupture of a mycotic aneurysm at 5 months and stent migration at 28 months). Other device-related complications comprised three proximal endoleaks, one of which required open surgical correction with removal of the stent graft, and two distal endoleaks, which were successfully treated with distal extension cuffs. CONCLUSION: In the mid term, endoluminal repair of thoracic aortic pathology appears to be a safe alternative to open surgery, but continued surveillance is essential.     

Anesthetic management of endovascular stent graft placement for thoracic aortic aneurysm using induction of transient cardiac asystole by ATP

We experienced anesthetic management of endovascular stent graft placement for thoracic aortic aneurysm in a 69-year-old patient. Under general anesthesia, ATP 20 mg was administered intravenously. However, heart rate and blood pressure did not decrease sufficiently for placement of a stent graft. After additional injection of ATP 30 mg, heart rate and systolic blood pressure decreased to 20 bpm and 60-70 mmHg, respectively, enabling the placement of a self-expanded type stent graft in the proper site. No clinical complications related to this procedure were observed. Induction of transient cardiac asystole by ATP is an easy and safe procedure for placement of a stent graft in a patient with thoracic aortic aneurysm.     

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??Chimney technique for aortic diseases involving supra-aortic branches in a single center SHU Chang, WANG Tun. Department of Vascular Surgery, the Second Xiangya Hospital, Central South University, Changsha 410011, China
Corresponding author: SHU Chang, E-mail??changshu01@yahoo.com
Abstract Objective To evaluate the mid- and long-term efficiency of thoracic endovascular aortic repair (TEVAR) with chimney technique for aortic arch disease involving the supra-aortic branches. Methods The clinical data of 57 cases of aortic arch diseases performed TEVAR with chimney technique from September 2009 to December 2013 in Department of Vascular Surgery, the Second Xiangya Hospital, Central South University were analyzed retrospectively. There were 2 cases (3.5%) of aortic arch aneurysm, 1 case (1.8%) of type I endoleak after TEVAR for thoracic aortic aneurysm, 1 case (1.8%) of type I endoleak after TEVAR for type B aortic dissection (TBAD), 53 cases (92.9%) of TBAD. One case was complicated with Marfan syndrome. Results All of the stent grafts were deployed as planned. Five cases had type II endoleak during TEVAR. One case received re-TEVAR and another chimney stent grafts deployment because of ischemia of branch arteries caused by migration of chimney stent grafts during anesthesia resuscitation. All patients followed up for 2 to 51 months. One case of TBAD received re-TEVAR for distal re-entry. One case died of cerebral hemorrhage 3 months later. No TEVAR related complications happened, such as stent graft migration, occlusion, fracture or type I endoleak during follow-up. Conclusion Chimney technique can be used with TEVAR to treat aortic arch disease invaded supra-aortic branches, which is reliable and stable. Reconstructed supra-aortic branches with covered stent is useful for prevention of post-TEVAR complications     

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.     

Inhibition of In-stent Restenosis in Rabbit Iliac Arteries with Photodynamic Therapy

OBJECTIVES: Photodynamic therapy (PDT, the combination of light with a photosensitising drug in the presence of oxygen) inhibits restenosis after angioplasty without stenting. This study assesses the potential of PDT for prevention of in-stent re-stenosis. DESIGN AND METHODS: Normal rabbits were given the photosensitising agent 5-aminolaevulinic acid (ALA) 60 mg/kg, 3 h prior to endovascular illumination of the iliac artery (635 nm at 50 J/cm(2)) either immediately before or after deployment of an oversized (3 mm diameter) stent. PDT treated arteries were retrieved 3 or 28 days later and assessed for cell counts and vascular morphometry. Control arteries (stent but no PDT) were examined at 28 days. RESULTS: There were no adverse events and all vessels were patent at the end of the study. At 3 days there was almost complete medial cell ablation when light was delivered before stent deployment (17+/-1 cells/hpf), with little effect when illumination followed stent deployment (184+/-17 cells/hpf, p<0.0001). Twenty-eight days after PDT, the neointimal areas were 1.41+/-0.52 mm(2) (stent with no PDT), 1.24+/-0.54 mm(2) (light after stent) and 0.60+/-0.21 mm(2) (light before stent) (p=0.004). CONCLUSIONS: PDT before stent deployment caused almost complete medial cell ablation at 3 days with inhibition of in-stent restenosis at 28 days. PDT is worthy of further study as an adjuvant to percutaneous intervention in patients with vascular disease.     

症状性主动脉穿透性溃疡的腔内修复术

目的 探讨症状性主动脉穿透性溃疡（penetrating atherosclerotic ulcer,PAU）的临床诊断和支架型人工血管腔内修复术的临床价值。方法 回顾分析2004年9月至2010年4月治疗的12例症状性PAU患者的临床资料,所有患者均有突发胸背部疼痛等急性主动脉综合征的临床表现,计算机断层扫描血管成像（computer tomography angiography,CTA）确诊为Stanford B型PAU,其中8例合并主动脉壁间血肿,所有患者均在全麻下接受支架型人工血管腔内修复术,两例附加杂交旁路手术延长近远侧锚定区。本组12例中10例患者获得随访,随访率83.3％。随访时间1～4年（中位时间36个月）,随访率83.3％ (10/12)。结果 12例患者共植入支架型人工血管12枚,其中植入支架直径32～40 mm,平均(35.7 ±2.5) mm,长度152 ～ 202 mm,平均(163±19) mm。1例溃疡较大病例支架人工血管植入后存在极少量内漏外,其他溃疡均隔绝满意。技术成功率100％。围手术期无不良事件发生。随访中患者无症状复发及死亡。CTA检查结果满意无内漏,1例少量内漏患者术后3个月复查内漏消失。结论 支架型人工血管腔内修复术因其微创、有效可能成为现阶段症状性PAU的首选治疗手段,术后严格的血压控制是长期疗效的有效保证。     

Aprotinin therapy for reoperative myocardial revascularization: a placebo-controlled study.

We tested the efficacy and safety of aprotinin in 169 patients undergoing isolated reoperative myocardial revascularization. Patients were randomly assigned to high-dose aprotinin, low-dose aprotinin, or placebo treatment groups in a double-blind, placebo-controlled study. Treatment groups did not differ significantly with respect to age, sex, red cell mass, number of grafts, use of internal thoracic artery, or incidence of preoperative aspirin therapy. Patients treated with aprotinin had a significant reduction in postoperative chest tube drainage (720 +/- 753, 866 +/- 1,636, and 1,121 +/- 683 mL, respectively, for high-dose aprotinin, low-dose aprotinin, and placebo; p < 0.001). Transfusion requirements were reduced in aprotinin-treated patients (2.1 +/- 4.2, 4.8 +/- 11.8, and 4.1 +/- 6.2 units for high-dose, low-dose, and placebo, respectively; p < 0.001). A similar reduction in chest tube drainage and transfusion requirements was seen in patients using aspirin preoperatively. Q-wave myocardial infarctions were increased in the aprotinin subgroups (17.5%, 14.3%, and 8.9% for high-dose, low-dose, and placebo groups; not significant). Acute vein graft thrombosis was found in six of 12 vein grafts studied at postmortem examination in patients receiving aprotinin but not in any of five grafts in patients receiving placebo. We conclude that aprotinin is extremely effective in reducing bleeding and transfusion requirements and may increase the risk of graft thrombosis.     

Endovascular Repair of Thoracic Aortic Aneurysms: Stent-graft Fixation across the Aortic Arch Vessels

The close proximity of the arch vessels to the origin of many thoracic aortic aneurysms (TAA) may result in placement of the stent struts across the left subclavian or carotid ostia. The purpose of this study is to determine the incidence and impact of transaortic arch vessel fixation during thoracic aortic stent graft deployment for the treatment of descending TAA. From May 1997 to July 2000, 20 patients (10 men, 10 women, mean age 82 years) with descending TAA were treated in the operating room with endoluminally placed stent grafts secured proximally to the thoracic aorta with a long (15-mm) uncovered stent segment (Talent LPS). Pre- and postoperative angiograms and IV contrast-enhanced spiral CT scans were performed in all cases. Follow-up contrast CT scans were obtained at 1, 3, 6, and 12 months and yearly thereafter to assess the adequacy of repair and to determine stent position and arch vessel patency. We found that thoracic aortic endograft fixation across the left aortic arch vessels occurs frequently during device placement and is associated with no early morbidity. Long-term follow-up is necessary to ensure that there are no late sequelae.