Dissecting descending thoracic and thoracoabdominal aortic aneurysms: Part II

Frozen elephant trunk and arch endografts for chronic thoracoabdominal aortic dissections

Chronic aortic dissecting aneurysms (TAAD) presenting after acute Stanford type A or B dissection includes both arch and/or thoracoabdominal aortic aneurysms (TAAA). Approximately 60% of patients who survive surgical treatment of acute type A aortic dissections will require another aortic procedure. Similarly, more than 70% of patients with chronic type B aortic dissections will experience false lumen dilation at 5-year follow-up, often requiring intervention. Open or hybrid aortic repairs of complex TAAD involving the arch and the TAAA are very demanding procedures for both patients and clinicians. Open surgery remains the first line therapy in fit patients. Recent development of branched arch devices has offered an alternative option for high-risk patients. Technical challenges associated with the endovascular management of these complex aneurysms include proximal sealing zone often located in the aortic arch or the ascending aorta, narrow true lumen working space, and aortic branch perfusion by either the true or false lumen, or both. Recent studies have reported encouraging results with endovascular treatment of these complex dissecting aneurysms, especially following open ascending aortic repair. The aim of this review was to describe the available strategies for arch repair in the setting of a chronic TAAD and to determine the subset of patients that can benefit from of a totally endovascular approach.

Conceptualizing treatment of uncomplicated type B dissection using the IDEAL framework

OBJECTIVE

The objective of this study was to introduce a new framework, called IDEAL (idea, development, exploration, assessment, and long-term study), to guide physicians, investigators, and regulatory agencies through the life cycle of device development and procedural refinement.

METHODS

This review describes the IDEAL framework and illustrates its application for treatment of uncomplicated type B dissection (uTBD) as an example of this process.

RESULTS

Components of IDEAL are summarized and applied to devices used to treat uTBD. Treatment of uTBD is currently in the exploration phase, with concurrent assessment and long-term study being facilitated by detailed registries.

CONCLUSIONS

The application of IDEAL to the development and monitoring of technologies standardizes the nomenclature, facilitates evidence-based practice, and enhances the innovation process.

Rapid Aneurysmal Sac Expansion Following Endovascular Repair of a Dissecting Thoracoabdominal Aneurysm

Endovascular repair of dissecting thoracoabdominal aneurysms (TAAA) is challenging and often requires multiple procedures. A 61-year-old man with a dissecting type-II TAAA treated first by placement of a thoracic endograft, and subsequently implantation of a fenestrated endograft. Six months postoperatively, a 10-mm increase of the aorta was observed. A reentry tear in left external iliac artery (EIA) was perfusing the false lumen in a retrograde fashion connecting with the endoleak caused by the inferior mesenteric artery and lumbar arteries. False lumen embolization of the left EIA and outflow vessels was performed. Thrombosis and rapid decrease of false lumen diameter was then observed. This case illustrates the complexity of endovascular management of extensive chronic aortic dissections.

Bypass Techniques for Descending Thoracic Aortic Surgery

The conduct of partial left heart bypass or partial car diopulmonary bypass (CPB) during surgery involving the descending thoracic aorta or thoracoabdominal aorta is one of the most unappreciated and misunder stood extracorporeal circulation procedures in cardio vascular surgery. It is different from conventional CPB, and although some uninitiated practitioners consider it simpler, it is in fact more complicated than conven tional CPB and involves different concepts. It requires expertise and skill in regulating the flow, pressure, and oxygenation of blood going to both the proximal and distal parts of the body and management of the special bypass or shunt procedures used, specialized monitor ing, and knowledge about the protection and preserva tion of organs both proximal and distal to the aortic clamping. It demands exquisite communication and un derstanding of the unique problems faced by the sur geon, anesthesiologist, and perfusionist.

Evaluation and management of symptomatic isolated spontaneous celiac trunk dissection

The purpose of this study is to describe 10 cases of symptomatic isolated spontaneous celiac trunk dissection (ISCTD) in order to evaluate the initial clinical presentation, diagnosis, treatment modalities and outcomes. A retrospective search was performed from 2009 to 2014 and 10 patients with ISCTD were included in the study. Patients with associated aortic and/or other visceral artery dissection were excluded. The following information was collected from each case: sex, age, associated risk factors, symptoms, diagnostic method, anatomic dissection pattern, treatment modality and outcome. Most patients were male (90%), with an average age of 44.8 years, and the most common symptom was abdominal pain (100%). Hypertension and vasculitis (polyarteritis nodosa) were the most frequent risk factors (40% and 30%, respectively). Diagnosis was made in all patients with computed tomography. Dissection was limited to the celiac trunk in three patients and extended to celiac branches in the other seven. Initial conservative treatment was attempted in every case and was successful in nine patients. In one case, initial conservative treatment was unsuccessful and arterial stenting with coil embolization of the false lumen was performed. After successful initial treatment, late progression of the dissection to aneurysmal dilatation was observed in two patients and it was decided to perform endovascular treatment. Mean follow-up was 19 months, ranging from 2 to 59 months. In conclusion, initial conservative treatment seems adequate for most patients with ISCTD. Long-term follow-up is mandatory, owing to the risk of later progression to aneurysm.

Acute Type-A aortic dissection with patent false lumen through to the abdominal aorta: effects of a conventional elephant trunk on malperfusion syndromes and narrowed true lumen

Background:

Narrowed true lumen and patent false lumen through to the terminal aorta is a high-risk condition for malperfusion syndromes (MS) in acute type-A aortic dissection. It is important to ascertain how the true and false lumens behave after surgery.

Patients and Methods:

We retrospectively investigated 45 patients with this pathology. The true lumen sizes at the narrowest levels above and below the superior mesenteric artery were followed by computed tomography after surgery (0-36 months).

Results:

Thirty-seven MS were seen in 23 patients. Hospital mortality was 8.9%. The narrowed true lumen was not enlarged in the first 6 months with a patent false lumen. The elephant trunk procedure did not improve the true lumen size. An extremely narrowed (≤3mm) true lumen was associated with a significantly high incidence of MS and mortality.

Conclusions:

High incidences of MS were observed in this particular pathology. An extremely narrowed true lumen was accompanied by a high incidence of MS and mortality.

Safety of elective management of synchronous aortic disease with simultaneous thoracic and aortic stent graft placement

BACKGROUND

Simultaneous treatment of multilevel aortic disease is controversial due to the theoretic increase in morbidity. This study was conducted to define the outcomes in patients treated electively with simultaneous thoracic endovascular aortic aneurysm repair (TEVAR) and abdominal aortic endovascular endografting for synchronous aortic pathology.

METHODS

Patients treated with simultaneous TEVAR and endovascular aneurysm repair (T&E) at the University of Florida were identified from a prospectively maintained endovascular aortic registry and compared with those treated with TEVAR alone (TA). The study excluded patients with urgent or emergency indications, thoracoabdominal or mycotic aneurysm, and those requiring chimney stents, fenestrations, or visceral debranching procedures. Demographics, anatomic characteristics, operative details, and periprocedural morbidity were recorded. Mortality and reintervention were estimated using life-table analysis.

RESULTS

From 2001 to 2011, 595 patients underwent TEVAR, of whom 457 had elective repair. Twenty-two (18 men, 82%) were identified who were treated electively with simultaneous T&E. Mean ± standard deviation age was 66 ± 9 years, and median follow-up was 8.8 months (range, 1-34 months). Operative indications for the procedure included dissection-related pathology in 10 (45%) and various combinations of degenerative etiologies in 12 (55%). Compared with TA, T&E patients had significantly higher blood loss (P < .0001), contrast exposure (P < .0001), fluoroscopy time (P < .0001), and operative time (P < .0001). The temporary spinal cord ischemia rate was 13.6% (n = 3) for the T&E group and 6.0% for TA (P = .15); however, the permanent spinal cord ischemia rate was 4% for both groups (P = .96). The 30-day mortality for T&E was 4.5% (n = 1) compared with 2.1% (n = 10) for TA. Temporary renal injury (defined by a 25% increase over baseline creatinine) occurred in two T&E patients (9.1%), with none requiring permanent hemodialysis; no significant difference was noted between the two groups (P = .14). One-year mortality and freedom from reintervention in the T&E patients were 81% and 91%, respectively.

CONCLUSIONS

Acceptable short-term morbidity and mortality can be achieved with T&E compared with TA, despite longer operative times, greater blood loss, and higher contrast exposure. There was a trend toward higher rates of renal and spinal cord injury, so implementation of strategies to reduce the potential of these complications or consideration of staged repair is recommended. Short-term reintervention rates are low, but longer follow-up and greater patient numbers are needed to determine procedural durability and applicability.

Rusults of classical crawford and hybrid operations in thoracic-abdominal aorta aneurysms treatment--comparative assessment

Thoracic-abdominal aortic aneurysms (TAAA) are still serious medical problem. Classical procedure requires two cavities approach and implantation of vascular prosthetic in the place of aneurysm--Crawford's procedure. Significant progress was made during last years by using endovascular procedures (stentgrafts). Alternative is hybrid procedure--prosthetic appliance of visceral and kidney arteries and then stentgraft implantation in whole thoracic-abdominal aorta. THE AIM OF THE STUDY was comparative analysis of classical and hybrid procedures in thoracic-abdominal aneurysms treatment.

MATERIAL AND METHODS

Between 1989-2011 in Department of Vascular, General and Transplantological Surgery Medical University in Wrocław and Surgical Department of 4th Military Clinical Hospital in Wrocław 53 patients were operated due to thoracic-abdominal aortic aneurysms. Classical Crawford's procedure was performed in 41 patients (group I) and hybrid procedure was performed in 12 patients (group II). Additionally 7 patients required aortic arc branches reconstruction due to achieve optimal conditions to stentgraft amplantation. Procedures were performed at one or two stages.

RESULTS

Mortality in patients treated classically (group I) depended on type of aneurysm in Crawford's classification. In type I-II mortality rate was 54% ((7 deaths/12 patients), in type III do V 17% (5 deaths/ 29 patients). In the group after hybrid procedure (group II) mortality rate was 28% (2 deaths/ 7 patients) in type I-II and 20% (1 death/5 patients) in type III to V. Observed serious perioperative complications.

CONCLUSIONS

1. Endovascular procedures development enabled introducing of new methods in thoracic-abdominal aortic aneurysms treatment (hybrid procedures) and allowed to get better results. 2. Clear advantage of hybrid procedures above classical Crawford's procedure is observed in type I and II of TAAA. 3. Mortality and morbidity rates recommend hybrid procedure in type I and II of TAAA. 4. Surgical results of classical and hybrid procedures in type III-V TAAA treatment are comparative, with indication on classical approach.

Descending thoracic aortic dissections

Type B dissection has traditionally been managed medically if uncomplicated and surgically if associated with complications. This practice has resulted in most centers reporting significant morbidity and mortality if open repair is required. In the setting of malperfusion, operative repair has been conjoined with fenestration or visceral stenting to improve outcomes. Endovascular stent grafts seem to offer an attractive alternative in the acute complicated type B dissection, with reduced mortality and morbidity, particularly paralysis, compared with open repair. It is reasonable to consider endovascular stent grafts as another tool in managing dissection, but to recognize that open surgical repair still plays an important role, and that the data that define indications and outcomes are still emerging.

Application of endograft to treat thoracic aortic pathologies: A single center experience

PURPOSE

To evaluate our experience of thoracic endoluminal graft (ELG) repair of various thoracic aortic pathologies using a commercially available device approved by the Food and Drug Administration. Our patient population includes patients eligible for open surgical repair and those with prohibitive surgical risk.

METHODS

From March 1998 to March 2006, endovascular stent repair of the thoracic aorta was performed on 406 patients with 324 patients (median age 72; 200 male) receiving the Gore Excluder endograft. Patient demographics, procedural characteristics, complications, including endoleak, spinal cord ischemia, and mortality, were retrospectively reviewed during follow-up. All patients were followed with chest computer tomography at 6 months and yearly. Statistical analysis was performed utilizing the SPSS Windows 11.0 program. Logistic regression (univariate) analysis used to identify risk factors for paraplegia; analysis of variance (ANOVA) for endoleak distribution; and chi(2) used to analyze variables. Survival analysis was done using SAS version 9.1 (SAS Institute, Cary, NC).

RESULTS

Three hundred twenty-four patients were treated with Gore Excluder graft between March 1998 and March 2006. One hundred fifty-seven patients (48.5%) had atherosclerotic aneurysms, 82 (25.3%) had dissections type B (DTB), 34 (10.5%) had penetrating ulcers (PU), 26 (8.0%) with pseudoaneurysms (PSA), 11 (3.4%) had transections (MVAT), 9 (2.8%) aorto-bronchial fistulas (AoBF), 4 (1.2%) embolization, and 1 (0.3%) aorto-esophageal fistula (AoEF). Preoperative aneurysm sac size in TAA ranged from 5 to 12 centimeters, average size 6.3 cm. Sac shrinkage occurred in 65% (102 of 157) of patients. Average postoperative sac size of 5.4 cm in a mean follow-up of 20.4 months. One hundred cases (31.5%) were nonelective; 49 (15.1%) were ruptures. Overall complication was 22.7%, 14.2% (46) in elective cases and 8.5% (28) in nonelective cases. Paraplegia occurred in five (1.5%) patients and paresis in three (0.9%); two of the latter improved and one resolved completely prior to discharge. Incidence of paraplegia was statistically significant (P value < .05) with retroperitoneal approach, perioperative blood loss greater than 1000 cc, and aortic coverage greater than 40 cm. Early endoleaks included 18 (5.5%) type I, four (1.2%) type II, and two (0.6%) type III. Thirty-day mortality was 5.5% (18 related deaths, including three intraoperative deaths). A log rank test did not find statistical differences in actuarial survival with 30-day related mortality between TAA and other pathologies (P = .29) or between DTB and other pathologies (P = .97). Late mortality was 9.6% with 31 unrelated deaths. Follow-up ranged between 1 month and 70 months, average 17 months.

CONCLUSIONS

Endoluminal grafting is a feasible alternative to open surgical repair for thoracic aortic pathologies. After more than 300 cases, 30-day morbidity and mortality compares favorably with open repair. Paraplegia remains low as a complication and increases in incidence with retroperitoneal approach, increased perioperative blood loss, and increased aortic coverage.

Serial magnetic resonance imaging correlates with neurological outcome in an experimental model of spinal cord ischemia

BACKGROUND

Paraplegia complicating surgical thoracoabdominal aneurysm (TAA) repair remains an unpredictable and poorly understood phenomenon. The ability to identify patients at increased risk of delayed paraplegia before the process becomes irreversible could allow early interventions to attenuate this risk.

METHODS

In a rabbit model of infra-renal spinal cord ischemia, serial T2 weighted (T2W) magnetic resonance (MR) imaging was performed 2- and 8 h after the ischemic insult with changes correlated with clinical outcome. Using the axial T2W images, signal intensity measurements of the lateral horns of the spinal cord were acquired, both above (that is, thoracolumbar cord) and below (that is, lumbar cord) the renal arteries. This ratio (lumbar/thoracolumbar cord signal intensity) was evaluated and compared between groups.

RESULTS

No changes were seen in the signal intensity of rabbits that remained neurologically intact. Rabbits with delayed paralysis showed a significant (P<0.01) decrease in signal intensity ratio at 2 h (1.13+/-0.03), while a significant (P<0.01) increase was noted in those rabbits with immediate persistent paralysis (1.43+/-0.04). There was a significant (P<0.01) increase in the signal intensity ratios at 2 h in the delayed paralysis group (1.55+/-0.14), with a further significant (P<0.01) increase at 8 h in the immediate persistent paralysis group (1.76+/-0.07).

CONCLUSIONS

Findings on MR imaging can differentiate clinical outcomes in this experimental model of spinal cord ischemia. While further studies are required, MR could be useful in predicting which patients are at risk for delayed paraplegia after TAA repair.

Presentation and outcome of Marfan's syndrome patients with dissection and thoraco-abdominal aortic aneurysm

BACKGROUND

In Marfan's syndrome, there is a paucity of data regarding intervention criteria for surgery of the dissected thoraco-abdominal aorta.

METHODS

A retrospective analysis of 22 Marfan's patients with distal aortic dissection managed between September 1999 and April 2006 was performed. Serial diameters and linear expansion rates were calculated from imaging studies and the outcome of intervention was analysed.

RESULTS

There were 14/22 male patients (median age 38 years), and 18 had prior aortic surgery. Surgery was recommended in 20 patients and undertaken in 19 (1 died prior to operation). Of the operated patients, 2 presented with rupture, 2 with airway obstruction, 1 with intermittent paraplegia and 14 underwent planned surgery for increased expansion rate or pain. All patients had residual type A or chronic type B dissection. The median aortic dimension at surgery was 6.7 cm (interquartile range (IQR) 5.5-8.2). The preoperative mean expansion rate increased from 0.5 cm/year to 1.7 cm/year (p<0.001), prior to operation. Fifteen patients underwent Crawford Extent II, two underwent Extent I and two underwent Extent III repair. Profound hypothermia and CSF drainage was used in 16 and 18 patients, respectively. There was no early mortality, paraplegia or renal failure. At a median postoperative follow-up of 56 months (range 6-86), the survival of the operated cohort was 90%.

CONCLUSIONS

Thoraco-abdominal aortic aneurysm repair in Marfan's syndrome can be performed with good outcomes. Intervention should be based on size or accelerated expansion. Any role of endovascular management needs careful consideration.

Tracheostomy after major vascular surgery

OBJECTIVES

Major vascular surgery such as aortic aneurysm repair may be associated with prolonged in-patient hospitalization. Certain patients undergo a tracheostomy to aid in weaning from mechanical ventilation or for secretion management. The authors hypothesized that tracheostomy after aortic reconstruction for aneurysmal disease was associated with poor outcomes.

DESIGN

A retrospective, observational study.

SETTING

Vascular surgical intensive care unit (ICU) of a tertiary referral hospital.

PARTICIPANTS

Eighty-one patients who underwent a tracheostomy after open thoracoabdominal or abdominal aortic aneurysm (AAA) repair between 1993 and 2002.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 1,940 patients who underwent aneurysm repair, 81 (4.2%) had a tracheostomy during their index hospitalization. Of those patients, 40.7% did not survive to hospital discharge. Postoperative sepsis was associated with an increased mortality (relative risk 2.45, 95% confidence interval [CI] 1.22-4.90). Many developed postoperative renal failure and were more likely to die in the hospital (relative risk 1.53, 95% CI 1.00-2.33). The preoperative diagnosis of chronic obstructive pulmonary disease (COPD) was not associated with increased mortality (relative risk 0.471, 95% CI 0.23-0.96). Thirty-two (39.5%) patients were transferred from the ICU to a chronic ventilator dependency unit (CVDU).

CONCLUSIONS

Tracheostomy in patients after aortic reconstruction for aneurysmal disease is associated with a high incidence of in-hospital mortality. Patients who survive to ICU discharge are likely to be transferred to a CVDU for further respiratory management. The preoperative diagnosis of COPD is associated with improved survival, whereas postoperative sepsis is associated with an increased mortality. These observations should be considered when counseling patients and their families regarding tracheostomy after aortic surgery.

Single Center Experience with a New Commercially Available Thoracic Endovascular Graft

PURPOSE

To evaluate the intra-operative performance and clinical outcome of a new commercially available stent-graft for the treatment of thoracic aortic diseases.

METHODS AND PATIENTS

From January 2003 to October 2004, 45 consecutive patients received endovascular treatment with the Zenith TX1 device for diseases of the thoracic aorta at a single center in northern Italy. Indications included disease of the descending thoracic aorta in 26 cases, of the aortic arch in 17 cases and of the thoraco-abdominal aorta in two cases. We treated 38 atherosclerotic aneurysms, two post-traumatic aortic ruptures, two penetrating ulcers, two chronic dissections and one case was treated for aortic bleeding after voluntary acid ingestion for attempted suicide. General anesthesia was used in 20 cases. Combined or hybrid endovascular and open surgical repair was performed in 11 patients. Mean follow-up was 7 months (range 1-22 months).

RESULTS

Technical success was obtained in 44 patients (98%). One primary type I endoleak occurred (2%). ICU was used in 12 cases with a mean stay of 1 day. The mean hospital stay was 6 days (range 4-13 days). There were no hospital deaths or strokes but one transient paraplegia (2%). A type II endoleak was observed in one case and resolved spontaneously 1 month later. No aneurysm enlargement, endograft migration or structural failures were observed during follow-up. Two late unrelated-deaths were observed.

CONCLUSIONS

This stent-graft does not fulfill all the characteristics of the ideal graft, however, it proved to be safe and allowed satisfactory short term results in this group of patients treated at a single center.

Endografting of the thoracic aorta:

BACKGROUND

Thoracic aortic dissections, ruptures, fistulae, and aneurysms pose a unique surgical challenge. Traditional repair of thoracic aortic aneurysms involves thoracotomy with graft interposition. Despite advances in perioperative care and both total and partial cardiopulmonary bypass, conventional surgery carries a significant morbidity and mortality. Principal complications include bleeding, paraplegia, stroke, cardiac events, pulmonary insufficiency, and renal failure. Recent enthusiasm for innovative endovascular therapies to treat aortic disease has spurred many centers to investigate endoluminal grafting of the thoracic aorta. Early reports on endovascular repair using custom made "first generation devices" demonstrated the technique to be feasible with a mortality and morbidity comparable to open repair.

METHODS AND RESULTS

From February 2000 to February 2001, endovascular stent graft repair of the thoracic aorta was performed in 46 patients (mean age 70; 29 male and 17 female) using the Gore Excluder. Twenty-three patients (50%) had atherosclerotic aneurysms, fourteen patients (30%) had dissections, three patients (7%) had aortobronochial fistulas, three patients (7%) had pseudoaneurysms, two patients (4%) had traumatic ruptures, and one patient (2%) had a ruptured aortic ulcer. Patient characteristics, procedural variables, outcomes, and complications were recorded. All patients were followed with chest CT scans at 1, 3, 6, and 12 months. Mean follow up was 9 months ranging from 1 to 15 months. All procedures were technically successful. There were no conversions. Average duration of the procedure was 120 minutes. Average length of stay was 6 days, but most patients left the hospital within 4 days (64%) after endoluminal grafting. Overall morbidity was 23%. Two patients (4%) had endoleaks that required a second procedure for successful repair. Two patients (4%) died in the immediate postoperative period. There were no cases of paraplegia. At follow-up, one patient had an endoleak found the day after the procedure and another patient had an endoleak 6 moths post procedure. Both were treated successfully with additional stent grafts. There were no cases of migration. One patient died of a myocardial infarction 6 months after graft placement. The Gore Excluder device was voluntarily recalled on February 26, 2001. Therefore, from June 2000 to January 2001, 37 patients underwent endovascular stent graft repair of the thoracic aorta for various disease entities using our customized thoracic graft (Endomed). Twenty-seven patients (73%) had aneurysms, six (16%) had dissections, two (5%) had pseudoaneurysms, one (2%) had a traumatic transection, and one patient (2%) had an embolizing ulcer. Patients were followed with CT scans at 1, 3, 6, and 12 months. All procedures were technically successful. There were no conversions. The average age was 68 years.(17-87). And the male and female ratio was 24/13. One patient died in the operating room from iliac rupture and one died from embolization/stroke in the immediate postoperative period. Two patients died within 30 days from comorbid factors. The total 30-day mortality was 10%. Two patients had endoleaks. One returned to the operating room and needed an additional cuff. The other had a small leak in a proximal dissection that is being followed. There were no cases of paraplegia.

CONCLUSION

Thoracic endoluminal grafting is a safe and feasible alternative to open graft repair and can be performed successfully with good results. Early data suggest that an endoluminal approach to these disease entities maybe favorable to open resection and graft replacement. Technical details of Endoluminal stent grafting of the thoracic aorta for different disease entities have been discussed at length.

Acute aortic dissection with side branch vessel occlusion: open surgical options

Acute aortic dissection is one of the most common catastrophes affecting the aorta. Because dissection can involve any aortic segment, the disease can manifest itself through a variety of clinical presentations. The most spectacular manifestation is frank rupture, usually into the pericardial or pleural cavity. Dissections of the ascending aorta are associated with rapidly fatal complications such as cardiac tamponade, major stroke, or massive myocardial infarction, justifying emergent operation. Dissections of the descending aorta are managed medically with surgery reserved for those patients with aortic rupture, aneurysmal dilatation, or ischemic symptoms. Aortic branch occlusion occurs in up to one third of patients with aortic dissection and is associated with increased risk of early death and serious complications. The therapeutic armamentarium of the vascular surgeon has evolved during the last 20 years to include endovascular (balloon fenestration or branch stenting) and surgical options. This article will focus on the open surgical management of patients with acute aortic dissection complicated by side branch occlusion and organ or limb malperfusion.

Endoluminal stent grafting of the thoracic aorta: initial experience with the Gore Excluder

PURPOSE

The purpose of this study was to describe our experience with endoluminal graft repair of a variety of thoracic aorta pathologies with a commercially developed device currently under investigation. Our patient population included patients eligible for open surgical repair and those with prohibitive surgical risk.

METHODS

From February 2000 to February 2001, endovascular stent-graft repair of the thoracic aorta was performed in 46 patients (mean age, 70 years; 29 male and 17 female patients) with the Gore Excluder. Twenty-three patients (50%) had atherosclerotic aneurysms, 14 patients (30%) had dissections, three patients (7%) had aortobronchial fistulas, three patients (7%) had pseudoaneurysms, two patients (4%) had traumatic ruptures, and one patient (2%) had a ruptured aortic ulcer. Patient characteristics, procedural variables, outcome, and complications were recorded. All patients were followed with chest computed tomographic scans at 1, 3, 6, and 12 months. Follow-up period ranged from 1 month to 15 months, with a mean of 8.5 months.

RESULTS

All the procedures were technically successful. There were no conversions. Average duration of the procedure was 120 minutes. Average length of stay was 6 days, but most patients (64%) left the hospital within 4 days after endoluminal grafting. The overall morbidity rate was 23%. Two patients (4%) had endoleaks that necessitated a second procedure for successful repair. Two patients (4%) died in the immediate postoperative period. There were no cases of paraplegia. At follow-up examination, one patient had an endoleak found the day after the procedure and another patient had an endoleak 6 months after the procedure. Both cases were treated successfully with additional stent-grafts. There were no cases of migration. One patient died of a myocardial infarction 6 months after graft placement. In patients treated for aneurysm (n = 23), the aneurysm diameter ranged from 5.0 to 9.5 cm (mean, 6.8 cm). Residual sac measurements were obtained at 1, 6, and 12 months, with mean sac reductions of 0.59 cm, 0.77 cm, and 0.85 cm, respectively. In three cases, the sac remained unchanged, without evidence of endoleak.

CONCLUSION

Thoracic endoluminal grafting with the Gore Excluder is a safe and feasible alternative to open graft repair and can be performed successfully with good results. Early data suggest an endoluminal approach to these disease entities may be favorable over classical resection and graft replacement.

Usefulness of transesophageal echocardiographic monitoring to improve the outcome of stent-graft treatment of thoracic aortic aneurysms

The stent-graft procedure is becoming an alternative to surgery for treatment of many diseases of the descending thoracic aorta. This study evaluated the role of transesophageal echocardiography (TEE), used in combination with fluoroscopy and angiography, in monitoring the outcome of stent-graft placement. Twenty-two consecutive patients were submitted to stent-graft positioning in the descending aorta for various pathologies (7 patients had type B aortic dissections, 6 had thoracic aneurysms, 2 had thoraco-abdominal aneurysms, and 7 had post-traumatic aortic aneurysms). Before stent-graft deployment, TEE changed the proximal site of stent positioning initially identified by angiography in 33% of patients (5 of 15) with aortic aneurysms because of calcifications or atheromas that could interfere with stent adhesion to the aortic wall and that were not seen on angiography. In 28% of patients (2 of 7) with aortic dissection, TEE showed the guidewire in the false lumen, allowing an immediate repositioning. After stent-graft deployment, color Doppler TEE showed a perigraft leak in 7 patients, whereas angiography detected a perigraft leak in only 2 patients (p = 0.02). In 4 of these patients, further balloon expansions resulted in resolution of the leak. In the remaining 3 patients, additional stent-graft positioning was necessary. Considering the total patient cohort, TEE yielded relevant information, resulting in procedure changes in 59% (13 of 22). In conclusion, TEE provided additional information with respect to angiography in all phases of stent-graft treatment, improving immediate outcome and reducing complications.

Aortic fenestration for acute or chronic aortic dissection: an uncommon but effective procedure

BACKGROUND

Aortic fenestration is rarely required for patients with acute or chronic aortic dissection. To better define its role and the indications for its use and to evaluate its success at relieving organ or limb malperfusion, we reviewed our experience with direct fenestration of the aorta.

METHODS

A retrospective analysis of all consecutive aortic fenestrations performed between January 1, 1979, and December 31, 1999, was performed. Fourteen patients, 12 men and two women (mean age, 59.6 years; range, 43-81), underwent fenestration of the aorta. All patients were hypertensive and had a history of tobacco use. By Stanford classification, there were three type A and 11 type B patients. In the acute dissection group (n = 7), indications for surgery were malperfusion in six patients (leg ischemia, 4; renal ischemia, 5; bowel ischemia, 3) and intra-abdominal bleeding from rupture in two. In the chronic dissection group (n = 7), indications for surgery were abdominal aortic aneurysm in 4 patients (infrarenal, 3; pararenal, 1), thoracoabdominal aneurysm in 1, hypertension from coarctation of the thoracic aorta in 1, and aortic occlusion with disabling claudication in 1.

RESULTS

Emergency aortic fenestration was performed in seven patients (surgically for 6 and percutaneously for 1). Fenestration level was infrarenal in four and pararenal in three. Concomitant abdominal aortic graft replacement was performed in four patients, combined with ascending aortic replacement (n = 1) and bilateral aortorenal bypasses (n = 1). In two patients, acute fenestration was performed for organ malperfusion after prior proximal aortic replacement (ascending aorta, 1; descending thoracic aorta, 1). Seven elective aortic fenestrations were performed for chronic dissection (descending thoracic aorta, 2; paravisceral aorta, 2; infrarenal aorta, 2 and pararenal aorta, 1). Concomitant aortic replacement was performed in six patients (abdominal aorta, 5; thoracoabdominal aorta, 1). Fenestration was successful at restoring flow in all 10 patients with malperfusion. Operative mortality for emergency fenestration was 43% (3/7). The three deaths that occurred were of patients with anuria or bowel ischemia, or both. There were no postoperative deaths for elective fenestration. At a mean follow-up of 5.1 years, there were no recurrences of malperfusion and no false aneurysm formations at the fenestration site.

CONCLUSION

Fenestration of the aorta can effectively relieve organ or limb ischemia. Bowel ischemia and anuria are indicators of dismal prognosis and emergency fenestration in these patients carries a high mortality. Elective fenestration combined with aortic replacement can be performed safely in chronic dissection. Aortic fenestration is indicated for carefully selected patients with malperfusion and offers durable benefits.

Endovascular grafts in the treatment of thoracic aortic aneurysms and pseudoaneurysms

The purpose of this study was to describe our experience with balloon and self-expanding endovascular grafts for the management of thoracic aortic lesions. Between February 1997 and June 1998, 20 endovascular grafts were implanted in 14 patients for the treatment of thoracic aortic aneurysms and pseudoaneurysms. Endovascular procedures were performed using one of four different devices: (1) Dacron-covered balloon-expandable Palmaztrade mark stent, (2) balloon-expandable Palmaz stent-PTFE graft prosthesis (BE-PS), (3) self-expanding internally supported Nitinol Dacron prosthesis (Vanguardtrade mark SE-V), and (4) self-expanding externally supported Nitinol PTFE prosthesis (Excludertrade mark SE-E). The results show that endovascular grafting represents a potentially important alternative therapy to open repair of the thoracic aorta. Self-expanding devices were, in our experience, easier to use and more accurately deployed.

Nonsurgical reconstruction of thoracic aortic dissection by stent-graft placement

BACKGROUND

The treatment of thoracic aortic dissection is guided by prognostic and anatomical information. Proximal dissection requires surgery, but the appropriate treatment of distal thoracic aortic dissection has not been determined, because surgery has failed to improve the prognosis.

METHODS

We prospectively evaluated the safety and efficacy of elective transluminal endovascular stent-graft insertion in 12 consecutive patients with descending (type B) aortic dissection and compared the results with surgery in 12 matched controls. In all 24 patients, aortic dissection was diagnosed by magnetic resonance angiography. In each group, the dissection involved the aortic arch in 3 patients and the descending thoracic aorta in all 12 patients. With the patient under general anesthesia, either surgical resection was undertaken or a custom-designed endovascular stent-graft was placed by unilateral arteriotomy.

RESULTS

Stent-graft placement resulted in no morbidity or mortality, whereas surgery for type B dissection was associated with four deaths (33 percent, P=0.09) and five serious adverse events (42 percent, P=0.04) within 12 months. Transluminal placement of the stent-graft prosthesis was successful in all patients, with no leakage; full expansion of the stents was ensured by balloon inflation at 2 to 3 atm. Sealing of the entry tear was monitored during the procedure by transesophageal ultrasonography and angiography, and thrombosis of the false lumen was confirmed in all 12 patients after a mean of three months by magnetic resonance imaging. There were no deaths or instances of paraplegia, stroke, embolization, side-branch occlusion, or infection in the stent-graft group; nine patients had postimplantation syndrome, with transient elevation of C-reactive protein levels and body temperature plus mild leukocytosis. All the patients who received stent-grafts recovered, as did seven patients who underwent surgery for type B dissection (58 percent) (P=0.04).

CONCLUSIONS

These preliminary observations suggest that elective, nonsurgical insertion of an endovascular stent-graft is safe and efficacious in selected patients who have thoracic aortic dissection and for whom surgery is indicated. Endoluminal repair may be useful for interventional reconstruction of thoracic aortic dissection.

Adjunctive therapy for spinal cord protection during thoracoabdominal aortic aneurysm repair

Paraplegia, resulting from spinal cord ischemia during thoracoabdominal aortic aneurysm (TAA) repair, continues to be a devastating complication. The incidence of neurological complications, including paraplegia and paraparesis following TAA repair, ranges from 4% to 32% and averages 13% for nondissecting TAA and higher for dissecting TAA. Our current understanding of spinal cord ischemia associated with TAA repair has evolved from animal research and clinical experience. The pathophysiology of spinal cord ischemia is intricately related to three physiological variables. These include the severity and duration of spinal cord ischemia, neuronal reperfusion after reestablishment of spinal cord blood flow, and the neuronal metabolic rate during the ischemic insult. We have developed a multimodality approach to the prevention of neurological deficits, during and after TAA repair, which includes minimizing the severity of spinal cord ischemia, reducing the anticipated reperfusion phenomenon, and lowering the spinal cord metabolic rate. Over the past 16 years, the senior author has undertaken surgical repair of 265 TAAs using a multimodality approach in the protection of spinal cord integrity. In our experience, a combination of adjunctive therapies is critical to minimize the ischemic interval, reduce the neuronal reperfusion injury, and decrease spinal cord metabolism. These techniques have evolved over time, resulting in an overall neurological deficit rate of 4.5% and a neurological deficit at the time of hospital discharge of 1.9%. This article will outline our multimodality approach for spinal cord protection during TAA repair.

Paraplegia after thoracoabdominal aortic aneurysm repair: is dissection a risk factor?

BACKGROUND

The association between aortic dissection and paraplegia or paraparesis (P/P) after thoracoabdominal aortic aneurysm repair is not clear.

METHODS

Six hundred sixty patients underwent thoracoabdominal aortic aneurysm repair from 1986 through 1995 using selective atriodistal bypass, liberal reattachment of critical intercostal arteries, moderate heparinization, and permissive mild hypothermia. Dissection was present in 163 patients (24.7%) and absent in 497 (75.3%).

RESULTS

Early mortality occurred in 7.4% overall, and did not differ between patients with nondissection, acute dissection, or chronic dissection. The incidence of P/P was 5.4% overall, 5.5% without dissection, and 5.0% with dissection. The risk of P/P for acute versus chronic dissection was 19% versus 2.9%, respectively (p = 0.011). Rupture and Crawford extent II were predictive of the development of P/P. In patients at high risk for P/P (ie, Crawford extent I or II), atriodistal bypass reduced the intercostal artery ischemic time, and reattachment of critical intercostal arteries (T8 to L1) reduced the incidence of P/P.

CONCLUSIONS

Acute dissection increases the risk of P/P after thoracoabdominal aortic aneurysm repair; using contemporary methods, however, chronic dissection does not increase the risk of postoperative P/P. Critical intercostal artery reattachment and atriodistal bypass are beneficial in patients undergoing extensive repairs.