Primary endoleakage in endovascular treatment of the thoracic aorta: importance of intraoperative transesophageal echocardiography

[Intraoperative transesophageal echocardiography as monitoring procedure in noncardiac surgery patients]

Transesophageal echocardiography (TEE) is firmly established in cardiac surgery for diagnostics, hemodynamic monitoring and as a guiding tool. Dynamic and (patho)physiological processes of the heart can be immediately depicted. Ideally, therapeutic changes can be derived. For this reason, TEE is increasingly used in high-risk non-cardiac surgery interventions and in the interventional setting. In the first part of this advanced training series, general aspects regarding TEE examinations as well as indications and contraindications are presented. Clinical fields of application, where TEE can play a role in hemodynamic monitoring are outlined. The second part focusses on an emergency examination pathway and differential diagnoses, which can be made in the event of intraoperative hemodynamic instability or unexplained hypoxemia using TEE. The article concludes with an outlook on the use of computer-aided evaluation of TEE images.

Perioperative transesophageal echocardiography for non-cardiac surgery

PURPOSE

The use of transesophageal echocardiography (TEE) has evolved to include patients undergoing high-risk non-cardiac procedures and patients with significant cardiac disease undergoing non-cardiac surgery. Implementation of basic TEE education in training programs has increased across a broad spectrum of procedures in the perioperative arena. This paper describes the use of perioperative TEE in non-cardiac surgery and provides an overview of the basic TEE examination.

PRINCIPAL FINDINGS

Perioperative TEE is used to monitor hemodynamic parameters in non-cardiac procedures where there is a high risk of hemodynamic instability. Its use extends to include moderate-risk procedures for patients with significant cardiac diseases such as low ejection fraction, hypertrophic cardiomyopathy, severe valve lesions, or congenital heart disease. Vascular procedures involving the aorta, blunt trauma, and liver transplantation are all examples of procedures that may benefit from TEE. Transesophageal echocardiography examination allows assessment of volume status, ventricular function, diagnosis of gross valvular pathology and pericardial tamponade, as well as close monitoring of cardiac output, response to therapy, and the impact of ongoing surgical manipulation. In patients with unexplained and unexpected hemodynamic instability, "rescue TEE" can be used to help identify the underlying cause.

CONCLUSIONS

Perioperative TEE is emerging as a preferred tool to manage hemodynamics in high-risk procedures and in high-risk patients undergoing non-cardiac surgery. A rescue TEE examination protocol is a helpful approach for early identification of the etiology of hemodynamic instability.

Intraoperative Detection of Persistent Endoleak by Detecting Residual Spontaneous Echocardiographic Contrast in the Aneurysmal Sac During Thoracic Endovascular Aortic Repair

Persistent endoleaks may lead to adverse events after endovascular aortic repair. We prospectively examined the relationship between intraoperative residual spontaneous echocardiographic contrast (SEC) within the aneurysmal sac and the incidence of postoperative endoleaks in 60 patients undergoing thoracic endovascular aortic repair. Patients with SEC had a higher incidence of postoperative endoleaks than did patients without SEC within a few days postoperatively (60.0% vs 12.5%, respectively; P < .001) and at 6 months postoperatively (40.0% vs 2.5%, respectively; P < .001). Intraoperative confirmation of the absence of SEC may identify patients at low risk for persistent endoleaks after thoracic endovascular aortic repair.

[Perioperative transesophageal echocardiography in non-cardiac surgery. Update]

AIM

The aim of this article is to impart knowledge concerning focused transesophageal echocardiographic examination (TEE) for non-cardiac surgery which is an essential part of perioperative monitoring. It allows a rapid echocardiographic examination without interference with the surgical field or under limited transthoracic examination conditions. New recommendations for a comprehensive perioperative TEE examination with expanded standard views and the recently published consensus statement for a shortened baseline examination were crucial for this study.

MATERIAL AND METHODS

The background is the peer-reviewed literature from PubMed.

RESULTS

Apart from cardiac surgery TEE has two main applications: firstly, the evaluation of patients developing acute life-threatening hemodynamic instability in the operating room, in the emergency room or in the intensive care unit (ICU). Secondly, TEE is used as planned intraoperative monitoring when severe hemodynamic, pulmonary or neurological complications are expected because of the type of surgery or due to the cardiopulmonary medical history of the patient. In 2013 a total of 11 relevant standard views were defined for the basic perioperative TEE examination in non-cardiac surgery. These 11 views should be performed for each patient. Appropriate extension to a comprehensive examination may be necessary if complex pathology is obvious.

DISCUSSION

Even in non-cardiac surgery TEE is an important tool allowing clarification of a life-threatening perioperative hemodynamic instability within a few minutes. Furthermore, the hemodynamic management of high-risk patients can be facilitated. Appropriate qualification and continuous training are necessary in order to assure the competence of the examiner.

The role of echocardiography in the early diagnosis of the complications of endovascular repair of blunt aortic injury

PURPOSE

Endovascular repair of traumatic aortic injury has been associated with severe procedural complications, including endoleaks, coverage of the left subclavian artery, stent collapse, access complications, and questionable durability. Echocardiography has proven to be a valuable tool in the intraoperative detection of these complications. In the current study, we report on the use of echocardiography as an early postoperative diagnostic technique for the evaluation of endovascular stent graft positioning in the intensive care setting.

METHODS

From January 2005 to January 2009, 14 patients who underwent endovascular repair of a blunt aortic injury were admitted in our intensive care unit. Transesophageal and/or transthoracic echocardiography were used as first-line diagnostic tools in the assessment of the endovascular graft position.

RESULTS

Twenty-eight percent of patients (4 of 14) developed a pressure gradient between upper and lower limbs (greater than 50 mm Hg), which presented with persistent hypertension, requiring antihypertensive therapy in high doses and difficult weaning. In all 4 patients, stent graft malposition was identified using echocardiography. The diagnosis was verified by computed tomography and aortography.

CONCLUSION

Noninvasive echocardiographic monitoring proved to be a valuable tool in the early diagnosis of postoperative stent graft malalignment. To our knowledge, this is the first time that echocardiography is described in the relevant literature as an early diagnostic technique in this setting.

Endovascular Approaches to Complex Thoracic Aortic Disease

Diseases of the thoracic aorta remain among the most lethal and difficult to treat conditions. In 2005, the US Food and Drug Administration approved the first endoprosthesis for the treatment of aneurysms of the descending thoracic aorta; at present, there are 3 thoracic devices approved by the US Food and Drug Administration. Although approved only for the treatment of descending aneurysms, thoracic endografting has other potential off-label applications, including acute and chronic aortic dissection and traumatic aortic transection. Endovascular repair of thoracic aortic pathology is emerging as the preferred treatment strategy in certain patients, as increasing data suggest that endovascular repair may be performed with lower peri-operative morbidity and mortality rates and similar midterm survival, when compared with standard open repair. However, because of anatomic constraints related to required endograft seal zones, a significant number of patients are excluded from standard endovascular repair. Hybrid techniques, including open aortic arch and thoracoabdominal debranching procedures, have been described to allow creation of proximal and/or distal landing zones for the stent graft seal. This review describes the surgical and anesthetic considerations relevant to thoracic endografting, with an emphasis on hybrid procedures used to treat more complex thoracic aortic pathology. Hybrid techniques may be performed with lower rates of morbidity and mortality than conventional open repair, and they appear to be a safe alternative to open repair for thoracoabdominal and aortic arch aneurysms in properly selected patients with significant comorbidity or prior open aortic surgery.

Transesophageal echocardiography and noncardiac surgery

The use of transesophageal echocardiography (TEE) for monitoring during cardiac and noncardiac surgery has increased exponentially over the past few decades. TEE has evolved from a diagnostic tool to a monitoring device and a procedural adjunct. The close proximity of the TEE transducer to the heart generates high-quality images of the intracardiac structures and their spatial orientation. The use of TEE in noncardiac and critical care settings is not well studied, and the evidence of the benefits of its use in these settings is lacking. Despite the widespread availability of TEE equipment in US hospitals, less than 30% of anesthesiologists are formally trained in the use of perioperative TEE. In this review, the safety and indications of TEE are reviewed and detailed analysis of the best available evidence in this regard is presented. Landmark trials evaluating the use of TEE and its therapeutic impact in noncardiac surgical setting are critically reviewed. This article details recommendations to familiarize anesthesiologists with TEE technology to exploit it to its fullest potential to achieve better patient monitoring standards and eventually improve outcome. Training of greater numbers of anesthesiologists in TEE is needed to increase awareness of the indications and contraindications. Until relatively inexpensive TEE equipment is available, the initial cost of equipment acquisition remains a significant prohibitive factor limiting its widespread use.

Endovascular treatment of atherosclerotic and other thoracic aortic aneurysms

The incidence of thoracic aortic aneurysms (TAAs) is increasing with the present rate of occurrence at 10.9 cases per 100,000 people per year. The estimated 5-year risk of rupture of a TAA with a diameter between 4 and 5.9 cm is 16%, but it rises to 31% for aneurysms ≥ 6 cm. Despite increasing awareness of the importance of early diagnosis and treatment options, there are no clear guidelines available at the time of writing. Nor is there any clear evidence for specific pharmacological treatment able to resolve or delay the disease progression. Endovascular treatment (EVT), proposed as an alternative to surgery, has been considered a therapeutic innovation, especially because it is minimally invasive, which allows treatment even in high surgical risk patients. Vascular imaging is crucial for patient selection, endoprosthesis choice, and planning of the treatment because not all aneurysms are suitable. Early and midterm results are encouraging, but long-term results are necessary to definitively assess reliability of stent-graft materials and improvement in patient survival. In the choice between surgical or endovascular repair of TAAs, many factors must be considered, including the clinical situation, comorbidities, anatomy, choice of equipment, and last, but not less important, experience of the clinical team.

Degenerative aneurysm of the descending aorta. Endovascular treatment

The incidence of thoracic aortic aneurysms has a rate of occurrence of 10.9 cases per 100,000 person/year, with an estimated 5-year risk of rupture ranging from 16% (diameter between 4 and 5.9 cm) to 31% (6 cm or more). Despite increasing awareness of the important role of early diagnosis in treatment options, guidelines about therapeutic strategies are actually lacking, as well as definite evidence of pharmacological treatment able to resolve or delay the disease progression. Endovascular treatment proposed as alternative to surgery has been considered a therapeutic innovation, especially because of low invasiveness, which allows to treat even high surgical risk patients. The procedure is performed under general anesthesia, mechanical ventilation and blood pressure invasive monitoring (right radial artery cannulation). The common femoral artery or external iliac artery are used for access after surgical exposure. After exposition of the artery, a 6F sheath is inserted and 5000 UI of heparin administered. Angiography is then performed to identify the lesion, landing zones and its relation to side branches. Endovascular stent-graft is thus loaded on an extra-stiff guidewire and delivered, with induced hypotension, under fluoroscopic and transesophageal echo control. Post procedural angiography and echocardiography control are performed to reveal the final result.

Results of endovascular repair of the thoracic aorta with the Talent Thoracic stent graft: The Talent Thoracic Retrospective Registry

BACKGROUND

Endovascular treatment of thoracic aortic diseases demonstrated low perioperative morbidity and mortality when compared with conventional open repair. Long-term effectiveness of this minimally invasive technique remains to be proven. The Talent Thoracic Retrospective Registry was designed to evaluate the impact of this therapy on patients treated in 7 major European referral centers over an 8-year period.

METHODS

Data from 457 consecutive patients (113 emergency and 344 elective cases) who underwent endovascular thoracic aortic repair with the Medtronic Talent Thoracic stent graft (Medtronic/AVE, Santa Rosa, Calif) were collected. Follow-up analysis (24 +/- 19.4 months, range 1-85.1 months) was based on clinical and imaging findings, including all adverse events. To ensure consistency of data interpretation and event reporting, one physician reviewed all adverse events and deaths for the whole cohort of patients. In the case of discrepancies, the treating physicians were queried.

FINDINGS

Among 422 patients who survived the interventional procedure (in-hospital mortality 5%, 23 patients), mortality during follow-up was 8.5% (36 patients), and in 11 of them the death was related to the aortic disease. Persistent endoleak was reported at imaging follow-up in 64 cases: 44 were primary (9.6%) and 21 occurred during follow-up (4.9%). Seven patients with persistent endoleak had aortic rupture during follow-up, at a variable time from 40 days to 35 months, and all subsequently died. A minor incidence of migration of the stent graft (7 cases), graft fabric alteration (2 cases), and modular disconnection (3 cases) was observed at imaging. Kaplan-Meier overall survival estimate at 1 year was 90.97%, at 3 years was 85.36%, and at 5 years was 77.49%. At the same intervals, freedom from a second procedure (either open conversion or endovascular) was 92.45%, 81.3%, and 70.0%, respectively.

CONCLUSION

Endovascular treatment for thoracic aortic disease with the Talent stent graft is associated with low early morbidity and mortality rates also for patients who are at high risk and treated on an emergency basis. Follow-up data indicate a substantial durability of the procedure with a high freedom from related death and secondary interventions.

How to guide stent-graft implantation in type B aortic dissection? Comparison of angiography, transesophageal echocardiography, and intravascular ultrasound

BACKGROUND

Despite growing interest in stent-graft implantation for type-B aortic dissection, there are no established recommendations to prepare and perform an implantation procedure.

METHODS AND RESULTS

We directly compared angiography (ANGIO), transesophageal echocardiography (TEE), and intravascular ultrasound (IVUS) intraprocedually before and after placement of 48 stent grafts in 42 consecutive patients (12 women, 61+/-11 years of age) with acute and chronic type-B aortic dissection for both usefulness and capability to guide aortic stent-graft implantation. Both IVUS and TEE are superior to ANGIO to identify multiple entries (52 and 43 versus 34; P<0.005 each), to diagnose false-lumen slow flow after stent-graft implantation (32 and 31 versus 24; P<0.005 each) and to detect incomplete stent apposition (18 and 16 versus 8; P<0.005 each). In comparison with ANGIO, guide wire position over the entire length of the aorta was documented more frequently by TEE and IVUS (40 and 42 versus 25; P<0.001 each). In 4 patients with abdominal extension of the dissection, only IVUS was able to accurately identify the false lumen over the entire length of the diseased aorta. TEE was superior to IVUS and ANGIO in the detection of endoleaks (5 versus 0 and 1; P<0.05 each). Intraprocedural ANGIO, TEE, and IVUS had been performed without complications in all patients.

CONCLUSIONS

TEE in conjunction with ANGIO appears to be advantageous and adds incremental information to safely guide stent-graft placement in type-B aortic dissection. Additional use of IVUS was found to be helpful in patients with complex anatomy and abdominal extension of the dissection.

INvestigation of STEnt grafts in patients with type B Aortic Dissection: design of the INSTEAD trial--a prospective, multicenter, European randomized trial

PURPOSE

This study describes the design of an ongoing randomized trial initiated to compare the 2-year outcome of uncomplicated type B aortic dissection when treated by endovascular implantation of a Medtronic Talent stent graft adjunctive to best medical treatment versus best medical treatment alone.

METHODS

Patients older than 18 years with type B aortic dissection as diagnosed by computed tomography or magnetic resonance angiography are randomized to either a thoracic aortic endoprosthesis and antihypertensive treatment, called "stent grafting," or a tailored antihypertensive treatment, called "medical treatment." Only patients in a clinically stable condition and without spontaneous thrombosis of the false lumen after 14 days of the index dissection are considered eligible for study inclusion.

RESULTS

Primary outcome measure is all-cause mortality. Secondary outcome variables include conversion to stent and/or surgery, induced thrombosis of the false lumen, cardiovascular morbidity, aortic expansion (>5 mm/y of maximum diameter including true and false lumina), quality of life, and length of intensive care unit and hospital stay. The study design calls for 136 patients to be randomized and monitored for 24 months.

CONCLUSIONS

The INSTEAD trial is the first randomized trial investigating the role of endoluminal treatment of uncomplicated type B aortic dissection. By the end of December 2004, 125 patients were randomized, accounting for 92% of the target. Final results of the INSTEAD trial should be available in 2006.

Transesophageal echocardiography–guided algorithm for stent-graft implantation in aortic dissection

OBJECTIVE

Endovascular stent-graft placement is replacing traditional surgery in type B aortic dissection. Usually stent-graft implantation is performed under fluoroscopic and angiographic guidance, but this relatively new procedure is still burdened with some complications. We investigated the value of a developed algorithm based on transesophageal echocardiography (TEE) for guiding stent-graft implantation in type B aortic dissection.

METHODS

Forty-two patients with type B aortic dissection (chronic in 28 patients with aneurysmal dilatation of the false lumen, and acute complicated in 14 patients) underwent endovascular stent-graft reconstruction of the descending thoracic aorta. TEE was always performed after angiography. TEE-induced variations of the procedure, based on the algorithm, were compared with initial angiography-based decisions.

RESULTS

TEE was decisive for guidewire repositioning (not possible with fluoroscopy) from the false to the true lumen in 3 patients and for correct guidewire entrance in an elephant trunk prosthesis in another patient. After stent-graft implantation color Doppler TEE enabled detection of proximal peri-stent leaks in 13 patients, whereas only 6 (46%) of the 13 leaks were detectable at angiography (P = .008). Most leaks were subsequently eliminated with balloon dilation or further stent grafting. Pulsed Doppler TEE was also useful for differentiating true leaks (13 patients) from Dacron porosity (7 patients). A pulsed-Doppler velocity cutoff value of 50 cm/s enabled differentiation of Dacron porosity (characterized by slow blood flow) from true peri-stent leak (fast flow). After stent-graft implantation TEE demonstrated new intimal tears in the thoracic aorta in 7 patients, whereas only 2 of the 7 new tears were detectable at angiography (P = .024); in 6 of 7 patients the new distal tears were subsequently resolved with placement of additional stents, whereas in a patient with Marfan syndrome new proximal tears determined a type I endoleak, which could not be resolved. Overall, TEE furnished decisive information additional to angiography in determining successful procedural changes in 16 of 42 patients (38%). There were no in-hospital deaths, and pre-discharge spiral computed tomograms showed a good outcome of stent-graft implantation in 37 of 42 patients (88%), with 5 residual type I endoleaks, all previously detected with TEE but impossible to eliminate with either balloon molding or further stent implantation. All but 2 patients (95%) are currently alive at mean follow-up of 30 +/- 18 months.

CONCLUSIONS

TEE algorithm is an easy and useful tool in the operating room to guide correct stent-graft positioning in type B aortic dissection.

Transoesophageal Echocardiogram Identifying the Source of Endoleak After Combined Open/Endovascular Repair of a Type 3 Thoracoabdominal Aortic Aneurysm

Open repair of thoracic aortic aneurysms is associated with significant morbidity and mortality. The introduction of endovascular repair has reduced both the morbidity and mortality. However, endovascular stent repair can be complicated by endoleaks. We report here the successful treatment of a type 2 endoleak following endovascular repair of a thoracoabdominal aortic aneurysm, using transesophageal echocardiography to assist in the localization of the thoracic endoleak.

Transesophageal echo-guided endovascular exclusion of thoracic aortic mobile thrombi

Mobile luminal thrombus of the descending thoracic aorta is an unusual finding in patients with peripheral embolization. The diagnosis is best made with transesophageal echography (TEE). Traditionally, systemic anticoagulation and selective surgical thrombectomy are standard treatment. We present a case report of recurrent mobile thrombus despite surgical thrombectomy and systemic anticoagulation. We treated it with endovascular exclusion of a descending thoracic aorta emboligenic lesion with an endoluminal stent graft, using simultaneous TEE and fluoroscopic intraoperative guidance. The patient remains symptom-free 9 months after stent-graft implantation. TEE-guided endoluminal exclusion should be considered in treatment of descending thoracic aorta emboligenic lesions.

The Importance of Intraoperative Transesophageal Echocardiography in Endovascular Repair of Thoracic Aortic Aneurysms

Endovascular repair of the aorta (EVAR) is a promising alternative to open repair. Transesophageal echocardiography (TEE) is a sensitive imaging modality for aortic disease. We reviewed our experience with TEE in thoracic EVAR. Seven patients underwent thoracic EVAR under general anesthesia. Intraoperative angiography and TEE were used to identify the extent of the aneurysm and guide placement of the stent. Doppler color flow was used to supplement angiography to detect flow within the aneurysmal sac after stent placement. The endograft was successfully deployed in six patients. Endoleak was identified by TEE in three patients and confirmed by angiography in two of them. EVAR was abandoned in one patient on the basis of TEE findings of extensive aortic dissection. We found TEE to be a valuable intraoperative tool for 1) identifying aortic pathology, 2) confirming that the guidewire is in the true lumen, 3) aiding stent graft positioning, and 4) supplementing angiography for detecting endoleaks. TEE can supplement information obtained by angiography to enhance the accuracy of EVAR and potentially improve outcomes. The anesthesiologist is ideally positioned to provide the endovascular team with vital information regarding stent positioning, endoleaks, and cardiac performance with a single imaging modality.

IMPLICATIONS

Endovascular repair is an emerging alternative to open surgery for aortic aneurysms. We found transesophageal echocardiography to be a valuable imaging tool for guiding placement of the endograft, detecting leaks around the endograft, and supplementing information derived from angiography during endograft deployment.

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.

Descending thoracic aortic diseases: stent-graft repair

PURPOSE

To evaluate endovascular treatment of descending thoracic aorta with commercially available self-expanding stent-grafts.

MATERIALS AND METHODS

Seventy patients with aortic dissection, intramural hemorrhage, degenerative and posttraumatic aneurysm, penetrating atherosclerotic ulcer, and pseudoaneurysm underwent endovascular treatment. Eleven patients had impending rupture and were treated on an emergency basis. Stent-grafts were customized or selected on the basis of spiral computed tomographic (CT) or magnetic resonance (MR) imaging measurements. Preprocedure diagnostic angiography was performed in patients with aortic dissection and in other selected patients. All procedures were performed in an operating room and monitored with digital subtraction angiography (DSA) and transesophageal echocardiography (TEE). Follow-up was at 1, 3, 6, and 12 months after treatment and yearly thereafter.

RESULTS

Stent positioning was technically successful in 68 cases. At DSA and TEE, complete aneurysm or false-lumen exclusion was achieved in 66 (97%) cases. No intraoperative mortality or complications occurred. In-hospital complications included transient monoparesis (one patient) and extension of dissection into ascending aorta (one patient) that was repaired surgically. Early endoleak was observed in five (7%) patients: In three (type 2), endoleak resolved spontaneously; in one (type 1), it was persistent; and in one (type 1), treatment was converted to surgery. At long term, one (1%) patient died of aortic rupture; another, of respiratory insufficiency. Five (7%) late endoleak (type 1, one caused by migration of the stent) cases were observed. In three (4%), endovascular treatment was successful; in two (3%), surgery was performed. In one patient with persistent postimplantation syndrome, treatment was converted to surgery after successful aneurysm sealing. Procedure failure (ie, aortic disease-related mortality or conversion to surgery) occurred in six (9%) patients.

CONCLUSION

Endovascular stent-graft repair is less invasive in patients with chronic and acute descending thoracic aortic aneurysm and dissection.

Stent-graft repair of the thoracic aorta: short-term results

The purpose of this study was to evaluate clinical feasibility and immediate outcome of stent-graft repair of the thoracic aorta. From December 1999 to January 2001, a total of 14 patients underwent stent-graft repair of the thoracic aorta. The underlying etiologies were traumatic rupture of the aortic isthmus in four cases, Stanford type B dissection in four, thoracic aortic aneurysm in three, penetrating atherosclerotic ulcer in two cases, and postoperative aortoesophageal fistula in one case. Stent-graft placement was performed under angiographic control in all cases in association with transesophageal echography in seven cases. The procedure was performed under emergency conditions in five cases. Thirteen patients presented contraindications for surgery. Stent-graft placement was successful in all cases. No further surgery has been performed in any case. Thus we conclude that endovascular treatment of the thoracic aorta using stent grafts is a promising therapeutic modality in patients with contraindications for conventional surgical treatment.

Indications for, timing of, and results of catheter-based treatment of traumatic injury to the aorta

OBJECTIVE

The optimal treatment for and timing of surgery to repair traumatic aortic injury are still controversial. Endovascular treatment is a viable option in patients with both acute and chronic aortic trauma. However, appropriate patient selection criteria, treatment timing, and long-term durability of endovascular repair remain to be defined. We sought to identify appropriate selection criteria and optimal timing of treatment as well as to assess the long-term durability of endovascular repair.

SUBJECTS AND METHODS

From July 1997 to December 2001, 19 patients with traumatic aortic injury (11 patients with acute and eight with chronic injuries) were selected for endovascular treatment. In all patients, the lesions were sited at the proximal segment of the descending aorta at a distance of 10 +/- 17 mm (mean +/- SD) from the left subclavian artery. Nine of the patients with acute injuries were treated after clinical stabilization of other severe associated lesions, whereas two patients, in whom hemodynamic and imaging findings suggested an impending rupture, received emergency treatment. Single-detector helical CT or MR imaging was used for patient selection and stent-graft customization before treatment and for evaluation of patients during the follow-up period.

RESULTS

Endovascular stent positioning was successful in all patients. None of the patients developed complications. Aneurysm exclusion and shrinkage were confirmed at followup examinations. A partial covering of the subclavian artery occurred in six patients without interrupting the blood flow. All patients remain asymptomatic after a mean follow-up period of 20 months (range, 1-56 months).

CONCLUSION

Endovascular repair represents an alternative, minimally invasive treatment, particularly suitable for use in patients with traumatic aortic injuries. The decision of whether to provide immediate emergency treatment or to delay treatment should be based on the lesion characteristics on imaging and clinical findings. The durability of treatment seems to be related to the absence of alteration to the aortic wall at the extremities.

Evolving experience with thoracic aortic stent graft repair

PURPOSE

We reviewed our initial thoracic aorta (TA) stent graft experience in 28 patients from the perspective of treatment with homemade devices (Dacron over Gianturco Z stents; 14 cases) and a commercial device (Excluder; W.L. Gore Co, Flagstaff, Ariz; 14 cases).

METHODS

From November 1996 to August 2001, 28 patients with a spectrum of disease (degenerative aneurysm, n = 18; chronic dissection, n = 4; pseudoaneurysm, n = 3, with 1 trauma and 2 anastomotic; intramural hematoma, n = 2; and coarctation, n = 1) underwent TA stent grafting. Clinical parameters included a mean age of 71 years, 12 female (43%) and 16 male (57%) patients, 14 of 28 patients (50%) with major comorbidities that prohibited open repair, and nine of 28 patients (32%) with urgent or ruptured conditions. Seven patients (25%) needed open surgical access to the aorta or iliac artery for either concomitant abdominal aortic aneurysm repair (n = 3) or device deployment (n = 4), and six of 28 patients (21%) needed left subclavian-carotid transposition to provide for an adequate proximal fixation site. Focal (<15 cm) grafts were used in 19 patients, and the remaining patients had at least two thirds of their descending aorta excluded.

RESULTS

The procedural mortality rate was 3.5% (1/28 patients); three additional deaths, (1 device-related) occurred during the mean follow-up period of 17 months. Access artery complications occurred in six of 28 patients (21%), with one fatal. No immediate or late open conversions were performed. One patient needed urgent dilation and stenting of a collapsed stent graft 3 weeks after deployment. Serious systemic complications included temporary dialysis (n = 1), congestive heart failure (n = 1), and unstable angina (n = 1). Complete exclusion of the TA lesion was noted in 27 of 28 cases (96%). No cases of spinal cord ischemia were noted. Ease and accuracy of deployment was superior for the second generation (commercial) device.

CONCLUSION

TA stent graft repair, although in evolution, appears to be a safe and effective alternative to open repair for many patients with a spectrum of TA disease. Prospective trials for individual diseases will be necessary to define its ultimate role.

Utility of intraoperative transesophageal echocardiography during endovascular stent-graft repair of acute thoracic aortic dissection

This study was undertaken to evaluate the utility and efficacy of intraoperative transesophageal echocardiography (TEE) in the endovascular management of patients with acute type B aortic dissection. Twelve consecutive patients with acute type B aortic dissection underwent elective endoluminal stent-graft repair in the operating room under angiographic and TEE guidance. The follow-up protocol included spiral CT scanning before discharge from the hospital to assess thrombosis exclusion of the aortic false lumen, perfusion of branch vessels, and the absence of perigraft leak. No complications related to the use of TEE were encountered. TEE clearly demonstrated the presence and extent of the dissection flap in all patients. After the procedure a persistent perigraft leak or residual flow into the false lumen was diagnosed by TEE in 6 patients, whereas intraoperative angiography visualized only 3 cases. Postoperative CT scan confirmed these findings. One patient died 2 months later by aortic rupture secondary to a persistent perigraft leak not treated (8.3% mortality). No postoperative paraplegia or visceral ischaemia were registered, although an asymptomatic occlusion of left subclavian artery was observed. TEE monitoring detects perigraft leakage, identifies the entry tear, and accurately demonstrates sealing of the false lumen. TEE is essential in our practice as an adjuvant to fluoroscopy to achieve optimal results during endovascular stent-graft repair of acute thoracic aortic dissection.

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.