Thoracoabdominal aortic aneurysm repair: review and update of current strategies

Differential impacts of clinical, anatomical, and procedural factors on early and late mortality following open thoracoabdominal aortic repair: a retrospective observational study

BACKGROUND

The operative outcomes of thoracoabdominal aortic aneurysms (TAAAs) are challenged by high operative mortality and disabling complications. This study aimed to explore the baseline clinical, anatomical, and procedural risk factors that impact early and late outcomes following open repair of TAAAs.

METHODS

We reviewed the medical records of 290 patients who underwent open repair of TAAAs between 1992 and 2020 at a tertiary referral center. Determinants of early mortality (within 30 days or in hospital) were analyzed using multivariable logistic regression models, while those of overall follow-up mortality were explored using multivariable Cox proportional hazards models and landmark analyses.

RESULTS

The rates of early mortality and spinal cord deficits were 13.1% and 11.0%, respectively, with Crawford extent II showing the highest rates. In the logistic regression models, older age (P < 0.001), high cardiopulmonary bypass (CPB) time (P < 0.001), and low surgical volume of the surgeon (P < 0.001) emerged as independent factors significantly associated with early mortality. During follow-up (median, 5.0 years; interquartile range, 1.1-7.6 years), 82 late deaths occurred (5.7%/patient-year). Cox proportional hazards models demonstrated that older age (P < 0.001) and low hemoglobin level (P = 0.032) were significant risk factors of overall mortality, while the landmark analyses revealed that the significant impacts of low surgical volume (P = 0.017), high CPB time (P = 0.002), and Crawford extent II (P = 0.017) on mortality only remained in the early postoperative period, without significant late impacts (all P > 0.05).

CONCLUSION

There were differential temporal impacts of perioperative risk variables on mortality in open repair of TAAAs, with older age and low hemoglobin level having significant impacts throughout the postoperative period, and low surgical volume, high CPB time, and Crawford extent II having impacts in the early postoperative phase.

Age is not a sole predictor of outcomes in octogenarians undergoing complex endovascular aortic repair

OBJECTIVE

To examine the perioperative, postoperative, and long-term outcomes of fenestrated/branched endovascular aneurysm repair (F/BEVAR) in octogenarians compared with nonoctogenarians.

METHODS

A multicenter, retrospective cohort study was conducted using the Vascular Quality Improvement database, which prospectively captures information on patients who undergo vascular surgery across 1021 academic and community hospitals in North America. All patients who underwent F/BEVAR endovascular aortic repair from 2012 to 2022 were included. Patients were stratified into two groups: those aged <80 years and those aged ≥80 years at the time of the procedure. The preoperative, intraoperative, and postoperative factors were compared between the two groups. The primary outcome was long-term all-cause mortality; secondary outcomes included aortic-specific mortality and aortic-specific reintervention.

RESULTS

A total of 6007 patients (aged <80 years, n = 4860; aged ≥80 years, n = 1147) who had undergone F/BEVAR procedures were included. No significant difference was found in technical success, postoperative length of stay, length of intensive care unit stay, postoperative bowel ischemia, and spinal cord ischemia. After adjustment for baseline covariates, octogenarians were more likely to suffer from a postoperative complication (odds ratio [OR]: 1.16; [95% confidence interval (CI): 0.98-1.37], P < .001) and be discharged to a rehabilitation center (OR: 1.60; [95% CI: 1.27-2.00], P < .001) or nursing home (OR: 2.23; [95% CI: 1.64-3.01], P < .001). Five-year survival was lower in octogenarians (83% vs 71%, hazard ratio [HR]: 1.70; [95% CI: 1.46-2.0], P < .0001). Multivariate Cox proportional hazard analysis demonstrated that age was associated with increased all-cause mortality (HR: 1.72, [95% CI: 1.39-2.12], P < .001) and aortic-specific mortality (HR: 1.92, [95% CI: 1.04-3.68], P = .038). Crawford extent II aortic disease was associated with an increase in all-cause mortality (HR 1.49; [95% CI: 1.01-2.19], P < .001), aortic-specific mortality (HR: 5.05; [95% CI: 1.35-18.9], P = .016), and aortic-specific reintervention (HR: 1.91; [95% CI: 1.24-2.93], P = .003). Functional dependence was associated with increased all-cause mortality (HR: 2.90; [95% CI: 1.87-4.51], P < .001) and aortic-specific mortality (HR: 4.93; [95% CI: 1.69-14.4], P = .004).

CONCLUSIONS

Our findings suggest that octogenarians do have a mildly increased mortality rate and rate of adverse events after F/BEVAR procedures. Despite this, when adjusted for other risk factors, on par with other medical comorbidities and therefore age should be strict exclusion criterion for F/BEVAR procedures, rather age should be considered in the global context of patient's aortic anatomy, health, and functional status.

Debranching abdominal aortic hybrid surgery for aortic diseases involving the visceral arteries

Objective

Aortic diseases involving branches of the visceral arteries mainly include thoracoabdominal aortic aneurysm (TAAA), aortic dissection (AD) and abdominal aortic aneurysm (AAA). The focus of treatment is to reconstruct the splanchnic arteries and restore blood supply to the organs. Commonly used methods include thoracoabdominal aortic replacement, thoracic endovascular aortic repair and hybrid approaches. Hybrid surgery for aortic disease involving the visceral arteries, consisting of visceral aortic debranching with retrograde revascularization of the celiac trunk and renal arteries and using stent grafts, has been previously described and may be considered particularly appealing in high-risk patients. This study retrospectively analyzed recorded data of patients and contrasted the outcomes with those of a similar group of patients who underwent conventional open repair surgery.

Methods

Between 2019 and 2022, 72 patients (52 men) with an average age of 61.57 ± 8.66 years (range, 36-79 years) underwent one-stage debranching abdominal aortic hybrid surgery. These patients, the hybrid group, underwent preoperative Computed Tomographic Angiography (CTA) and had been diagnosed with aortic disease (aneurysm or dissection) involving the visceral arteries and were at high risk for open repair. The criteria used to define these patients as high-risk group who are in the need of hybrid treatment were American Society of Anesthesiologists (ASA) class 3 or 4. In all cases, we accomplished total visceral aortic debranching through a previous visceral artery retrograde revascularization with synthetic grafts (customized Y or four-bifurcated grafts), and aortic endovascular repair with one of two different commercially produced stent grafts (Medtronic® and Lifetech®). In some cases, we chose to connect the renal artery to the artificial vessel with a stent graft (Viabahn) and partly or totally anastomosed. We analyzed the results and compared the outcomes of the hybrid group with those of a similar group of 46 patients (36 men) with an average age 54.15 ± 12.12 years (range, 32-76). These 46 patients, the conventional open group, were selected for having had thoracoabdominal aortic replacement between 2019 and 2022.

Results

In the hybrid group, 72 visceral bypasses were completed, and endovascular repair was successful in all cases. No intraoperative deaths occurred. Perioperative mortality was 2.78%, and perioperative morbidity was 9.72% (renal insufficiency in 1, unilateral renal infarction in 5, Intestinal ischemia in 1). At 1-month postoperative CTA showed 2 endoleaks, one of which was intervened. At follow-up, there were unplanned reoperation rate of 4.29% and 5 (7.14%) deaths. The remaining patients' grafts were patent at postoperative CTA and no endoleak or stent graft migration had occurred. In the conventional open group, 1 died intraoperatively, 4 died perioperatively, perioperative mortality was 10.87% and complications were respiratory failure in 5, intestinal paralysis/necrosis in 4, renal insufficiency in 17, and paraplegia in 2. At follow-up, 5 (12.20%) patients presented with synthetic grafts hematoma 4 (9.76%) patient died, and 6 (14.63%) patients required unplanned reoperation intervention.

Conclusion

Hybrid surgery is technically feasible in selected cases. For aortic diseases involving the visceral arteries, the application of hybrid abdominal aorta debranching can simplify the operation process, decrease the risks of mortality and morbidity in high-risk and high-age populations and decrease the incidence of various complications while achieving ideal early clinical efficacy. However, a larger series is required for valid statistical comparisons, and longer follow-ups are necessary to evaluate the long-term efficacy of hybrid surgery.

Spinal drainage complications after aortic surgery

OBJECTIVE/BACKGROUND

Spinal drain (SD) placement is an adjunct used in open and endovascular aortic surgery to mitigate the risk of spinal cord injury. SD placement can lead to subdural hematoma and intracranial hemorrhage (SDH/ICH). Previous studies have highlighted a correlation between incidence of SDH/ICH and amount of cerebrospinal fluid (CSF) drained. We have two philosophies of SD management in our institution. One protocol allows fluid removal for pressure >10 cm H₂O with no volume restriction. A second, similar protocol restricts CSF drainage to <25 mL/h. We examined SD complications and the influence of volume restriction.

METHODS

Patients were identified according to the Current Procedure Terminology codes for SD placement, thoracic endovascular aortic repair, fenestrated/branched endovascular aortic repair, endovascular abdominal aortic repair, and open thoracic or thoracoabdominal aortic repair between January 1, 2012, and December 31, 2015. Patients' demographics included age, gender, race, body mass index, and comorbidities such as hypertension, chronic obstructive pulmonary disease, stroke, transient ischemic attack, diabetes mellitus, bleeding disorder, and connective tissue disorders. Management protocol was classified as volume independent (VI) or volume dependent (VD) by physician order. Postoperative complications related to the SD were noted.

RESULTS

We identified 948 patients who had an SD placed during the study period; 473 were done before aortic surgeries. A total of 364 patients (77%) underwent endovascular aortic surgery. The mean age at the time of procedure was 67.2 years, and 66% of patients were male. Thirty-nine patients (8.3%) were noted to have connective tissue disorders. Bloody SD placement occurred in 14 patients (3.1%) requiring rescheduling of the operation. SDH/ICH occurred in 11 patients (2.3%), postoperative blood tinged SD output in 94 patients (19.9 %), and 22 patients (4.7 %) had a CSF leak after SD removal. The incidence of SDH/ICH was not affected by the management protocol (2.6% VI vs 2.0% VD, P = .66), whereas the incidence of postoperative blood tinged SD output was significantly higher in the VI group (25.1% VI vs 15.0% VD, P = .006). Perioperative low-dose aspirin (81 mg) and prophylactic subcutaneous heparin did not increase the incidence of SDH/ICH. Postoperative thrombocytopenia was found to be associated with higher incidence of SDH/ICH (median 86,000 vs 113,000, P = .002).

CONCLUSIONS

Severe complications of SD placement (SDH/ICH) occur in 2.3% of SD patients undergoing aortic surgery, and the risk is higher in the setting of postoperative thrombocytopenia. SD volume limitation, blood tinged drainage, antiplatelet medication, and low-dose heparin do not affect the risk of SDH/ICH. The risks of spinal drains for aortic surgery should be balanced against potential benefits.

Physician-Modified Branched Double-Trunk Stent-Graft (PBDS) for Thoracoabdominal Aortic Aneurysm

PURPOSE

To describe the preliminary experience of using physician-modified, branched, double-trunk stent-grafts (PBDS) for treating thoracoabdominal aortic aneurysms (TAAA).

MATERIALS AND METHODS

Ten (10) patients with TAAA were included in the study from June 2017 to March 2020. The technical success, perioperative complications, re-intervention, and patency of branch arteries were assessed.

RESULTS

The technical success rate was 100%. There were four type III endoleaks (40%) recorded in the perioperative period. The median follow-up was 13.4 months (range, 3-36 months). During follow-up, two renal stent-graft occlusions (2 of 37 visceral arteries reconstructed, 5.4%), one cerebral infarction (1 of 10, 10%) and one paraplegia (1 of 10, 10%) occurred. No aortic-related death was recorded.

CONCLUSION

PBDS is useful in sealing TAAA and preventing visceral branches, providing an option for patients unsuited for open surgical repair. A larger sample size of patients is required to confirm the safety and effectiveness of this technique.

A three-tier Rescue stent improves outcomes over balloon occlusion in a porcine model of noncompressible hemorrhage

BACKGROUND

Noncompressible hemorrhage remains a high-mortality injury, and aortic balloon occlusion poses limitations in terms of distal ischemic injury. Our hypothesis was that a retrievable Rescue stent would confer improved outcome over aortic balloon occlusion.

METHODS

A three-tier, retrievable stent graft was laser welded from nitinol and polytetrafluoroethylene to provide rapid thoracic and abdominal coverage with an interval bare metal segment to preserve visceral flow. Anesthetized swine had injury of the thoracic or abdominal aorta followed by balloon occlusion or a Rescue stent. A 1-hour long damage-control phase with blood repletion was used to simulate the prolonged interval between injury and repair, especially in the battlefield setting. Following the damage-control phase, the balloon or stent were retrieved followed by vascular repair and recovery to 48 hours. Animals were compared in terms of hemodynamics, blood loss, neurophysiologic spinal cord ischemia, ischemic organ injury, and survival.

RESULTS

Despite antegrade hemorrhage control, balloon occlusion averaged 3.5 L of retrograde hemorrhage, loss of visceral perfusion, and permanent spinal cord ischemia by neurophysiology in six of seven animals. After permanent repair, all balloon occlusion animals died with only a single short term (5 hours) survivor. Conversely, Rescue stent animals revealed rapid hemorrhage control (in under 2 minutes) whether the injury was thoracic or abdominal with improved hemodynamics, preserved visceral flow, reduced spinal cord ischemia, negligible histologic organ injury and survival to end of study in all abdominal injured animals (n = 6) and four of six thoracic injured animals, with two deaths related to arrhythmia.

CONCLUSION

Compared with aortic balloon occlusion, a Rescue stent offers superior hemorrhage control and survival by virtue of reduced ischemic injury and direct control of the hemorrhagic injury. The Rescue stent may become a useful tool for damage control, especially on the battlefield where definitive repair presents logistical challenges.

Endovascular Repair of Thoracic Aortic Disease: Early and Midterm Experience

Thoracic aorta disease remains a challenging problem, and despite improvements, open repair techniques are still associated with significant morbidity and mortality. This is a retrospective review of 53 consecutive patients with thoracic aortic pathology who were treated with endovascular repair between September 1998 and December 2004 at a tertiary-care hospital. Endovascular stent graft placement was performed on 23 elective and 30 emergent patients (34 male patients, mean age 66 years, 21 to 85 years). Completion angiography revealed no endoleak in 47 (89%) patients, a type I endoleak in 4 patients, and a type II endoleak in 2 patients. Operative 30-day mortality for elective aneurysms (n = 22), emergent aneurysms (n = 10), dissection (n = 3), penetrating aortic ulcers (n = 7), and trauma (n = 11) was 0%, 40%, 0%, 29%, and 9%, respectively. In total, 46 (87%) patients survived 30 days, and 36 (78.3%) of the survivors were discharged home free of complications. Two patients (4%) experienced paraplegia. Median follow-up was 22 months (1 to 72 months). Intermediate-term results revealed 41 (89%) patients free of endoleak, stent migration, or aneurysmal expansion. Two (4%) patients required reintervention with an additional stent graft. There were 2 (4%) patients with late aortic-related deaths and four (9%) patients with non—aorticrelated late deaths. Endovascular stent graft placement for thoracic aorta disease can be performed successfully and safely with good perioperative and intermediate-term outcomes. Stent graft complication and reintervention rates are low, whereas intermediate survival rates are good. Long-term efficacy still needs to be evaluated.

Current status of endovascular treatment for thoracoabdominal aortic aneurysms

Open surgical repair (OSR) for thoracoabdominal aortic aneurysms (TAAAs) is maximally invasive and associated with high rates of operative mortality and perioperative complications including spinal cord ischemia (SCI), despite improvements in surgical techniques and perioperative care. Elderly patients, patients with a history of aortic surgery, and patients with severe comorbidities are often considered ineligible for this surgery and endovascular treatment may be their only treatment option. Total endovascular aneurysm repair (t-EVAR) without debranching surgery does not require thoracotomy and laparotomy and could improve the outcomes of these patients. t-EVAR includes fenestrated EVAR (f-EVAR), multi-branched EVAR (b-EVAR), and physician-modified fenestration endograft (PMFG). Although these techniques have achieved lower mortality rates than OSR, there are concerns about perioperative complications including limb ischemia, SCI, and long-term outcomes such as endograft migration and endoleaks (ELs). This article provides an overview of available endovascular devices for TAAAs and reviews the short and mid-term results of t-EVAR, as well as alternative options.

Spinal Subarachnoid Hematoma After Cerebrospinal Fluid Drainage in Thoracoabdominal Aortic Aneurysm Repair: Case Report and Literature Review

BACKGROUND

Cerebrospinal fluid (CSF) drainage reduces the risk of paraplegia in thoracoabdominal aortic aneurysm (TAAA) repair. Intracranial hemorrhage after TAAA repair has been reported as a rare complication of CSF drainage; however, spinal subarachnoid hematoma has never been reported. Here, we present a case of lumbosacral subarachnoid hematoma after CSF drainage in TAAA repair.

CASE DESCRIPTION

The patient was a 76-year-old man who was hospitalized for TAAA repair. Just before the operation, a CSF drainage catheter was inserted into the L4/5 vertebral interspace. Continuous CSF drainage was performed during the operation. The CSF drain was clamped just after the operation, and the drainage catheters were removed at 24 hours after the operation. On postoperative day 1, the patient experienced pain and paralysis in both lower limbs that worsened over time. Magnetic resonance imaging of the brain and spinal cord was indicative of a spinal subarachnoid hematoma. Removal of hematoma with thoracolumbar and lumbosacral laminectomy was performed, and immediately after the surgery, the pain and paralysis in both lower limbs improved. Six months after the removal of the hematoma, the paralysis in both lower limbs completely resolved and the patient achieved the preinjury activity level.

CONCLUSIONS

We present a rare case of lumbosacral subarachnoid hematoma after CSF drainage in TAAA repair. We should consider spinal subarachnoid hematoma when paralysis in the lower limbs occurs after CSF drainage.

Endovascular Treatment of Various Aortic Pathologies: Review of the Latest Data and Technologies

The technologies and innovations applicable to endovascular treatment for complex aortic pathologies have progressed rapidly over the last two decades. Although the initial outcomes of an endovascular aortic repair have been excellent, as long-term data became available, complications including endoleaks, endograft migration, and endograft infection have become apparent and are of concern. Previously, the indication for endovascular therapy was restricted to descending thoracic aortic aneurysms and abdominal aortic aneurysms. However, its indication has expanded along with the improvement of techniques and devices, and currently, it has become possible to treat pararenal aortic aneurysms and Crawford type 4 thoracoabdominal aortic aneurysm (TAAA) using the off-the-shelf devices. Additionally, custom-made devices allow for the treatment of arch or more extensive TAAAs. Endovascular treatment is applied not only to aneurysms but also to acute/chronic dissections. However, long-term outcomes are still unclear. This article provides an overview of available devices and the results of endovascular treatment for various aortic pathologies.

Can Recognition of Spinal Ischemia Be Improved? Application of Motor-Evoked Potentials, Serum Markers, and Breath Gas Analysis in an Acutely Instrumented Pig Model

BACKGROUND

Paraplegia due to spinal cord ischemia (SCI) is a serious complication after repair of thoracoabdominal aortic aneurysms. For prevention and early treatment of spinal ischemia, intraoperative monitoring of spinal cord integrity is essential. This study was intended to improve recognition of SCI through a combination of transcranial motor-evoked potentials (tc-MEPs), serum markers, and innovative breath analysis.

METHODS

In 9 female German Landrace pigs, tc-MEPs were captured, markers of neuronal damage were determined in blood, and volatile organic compounds (VOCs) were analyzed in exhaled air. After thoraco-phrenico-laparotomy, SCI was initiated through sequential clamping (n = 4) or permanently ligating (n = 5) SAs of the abdominal and thoracic aorta in caudocranial orientation until a drop in the tc-MEPs to at least 25% of the baseline was recorded. VOCs in breath were determined by means of solid-phase microextraction coupled with gas chromatography-mass spectrometry. After waking up, clinical and neurological status was evaluated (Tarlov score). Spinal cord histology was obtained in postmortem.

RESULTS

Permanent vessel ligature induced a worse neurological outcome and a higher number of necrotic motor neurons compared to clamping. Changes of serum markers remained unspecific. After laparotomy, exhaled acetone and isopropanol showed highest concentrations, and pentane and hexane increased during ischemia-reperfusion injury.

CONCLUSIONS

To mimic spinal ischemia occurring in humans during aortic aneurysm repair, animal models have to be meticulously evaluated concerning vascular anatomy and function. Volatiles from breath indicated metabolic stress during surgery and oxidative damage through ischemia reperfusion. Breath VOCs may provide complimentary information to conventional monitoring methods.

Natural history of the proximal aorta in patients with descending thoracic aortic disease

OBJECTIVE

This study investigated the growth and behavior of the ascending aorta in patients with descending thoracic aortic disease.

METHODS

We examined 200 patients with descending thoracic aortic disease including acute type B dissection (n = 95), chronic type B dissection (n = 38), intramural hematoma (n = 23), and thoracoabdominal aortic aneurysms (n = 44). Images from computed tomography and magnetic resonance imaging were evaluated after three-dimensional reconstruction to examine the growth rate in those with >1 year of imaging follow-up (n = 108). Survival data were derived from all 200 patients in this study.

RESULTS

Average proximal aortic dimensions at the index image were relatively small, measuring 3.65 ± 0.51 cm in the root, 3.67 ± 0.48 cm in the ascending aorta, and 3.50 ± 0.44 cm in the proximal arch. Average growth rate was low for the aortic root, ascending aorta, and proximal arch at 0.36 ± 0.64 mm/y, 0.26 ± 0.44 mm/y, and 0.25 ± 0.44 mm/y, respectively. There was no difference in baseline proximal aortic dimensions and growth rate between the four subgroups. An index aortic diameter ≥4.1 cm grew faster than those <4.1 cm at the ascending aorta (P = .028) and proximal arch (P = .019). There was no difference in aortic growth rates at the aortic root (P = .887). After the index scan, five patients underwent six ascending aortic replacement procedures, leading to a 3% ascending aortic intervention rate. Overall median life expectancy was 86.15 years.

CONCLUSIONS

Native ascending aortic growth in patients with descending thoracic aortic disease is slow. We suggest regular follow-up for index ascending aorta ≥4.1 cm because of its larger initial size and more rapid growth.

Spinal cord injury as a complication of thoracic endovascular aneurysm repair

OBJECTIVE

Spinal cord ischemia (SCI) is a devastating complication of thoracic aortic aneurysm repair in the era of thoracic endovascular aneurysm repair (TEVAR). This review aims to clarify the causes of SCI during TEVAR and to propose ways that it may be prevented.

METHODS AND RESULTS

We performed an extensive literature search of SCI during TEVAR. Based on the existing literature, we examined the anatomy of the anterior spinal cord artery, which supplies blood to the anterior aspect of the spinal cord, and discuss reported effective ways to prevent SCI during TEVAR, including augmentation of arterial blood pressure and drainage of cerebrospinal fluid.

CONCLUSION

After reviewing the mechanism of SCI during TEVAR, we evaluated promising preventative measures.

The efficacy and risk of cerebrospinal fluid drainage for thoracoabdominal aortic aneurysm repair: a retrospective observational comparison between drainage and non-drainage

Objectives

We reviewed our experiences with thoracoabdominal aortic aneurysm (TAAA) repair to assess the efficacy of cerebrospinal fluid drainage (CSFD) to prevent the neurological deficits and complications associated with CSFD.

Methods

Between 2002 and 2015, 118 patients underwent TAAA repair. Seventy-eight patients underwent CSFD for 2.7 ± 1.1 days after surgery. CSFD was not performed for the other 40 patients due to an urgent situation, chronic disseminated intravascular coagulation or anatomical difficulties.

Results

There were 5 in-hospital deaths (4.2%). The neurological complications included paraplegia ( n  = 14, 11.9%), paraparesis ( n  = 3, 2.5%), cerebral infarction ( n  = 11, 9.3%) and intracranial haemorrhage ( n  = 1, 0.85%), none related to CSFD. The complications related to CSFD included headaches ( n  = 13, 11.0%), subdural haematoma (which was treated conservatively) ( n  = 1, 0.85%), a neurological symptom of the bilateral thighs ( n  = 1, 0.85%), pale haemorrhagic discharge ( n  = 2, 1.7%) and a fractured catheter ( n  = 1, 0.85%). Eight patients had paraplegia and 1 patient had paraparesis among the 78 patients who underwent CSFD (9/78, 11.5%); among the 40 patients who did not undergo CSFD, 6 had paraplegia and 2 had paraparesis (8/40, 20.0%). A multivariate analysis demonstrated that CSFD had a significant protective effect for the spinal cord (odds ratio = 0.045, P  = 0.007).

Conclusions

CSFD effectively prevented spinal cord dysfunction in TAAA repair. However, some serious complications occurred, including subdural haematoma and a fractured catheter. It is therefore important to recognize both the efficacy and the risks of CSFD in TAAA repair.

The use of lumbar drains in preventing spinal cord injury following thoracoabdominal aortic aneurysm repair: an updated systematic review and meta-analysis

OBJECTIVE Paraplegia and paraparesis following aortic aneurysm repair occur at a substantially high rate and are often catastrophic to patients, their families, and the overall health care system. Spinal cord injury (SCI) following open thoracoabdominal aortic aneurysm (TAAA) repair is reported to be as high as 20% in historical controls. The goal of this study was to determine the impact of CSF drainage (CSFD) on SCI following TAAA repair. METHODS In August 2015 a systematic literature search was performed using clinicaltrials.gov , the Cochrane Library, PubMed/MEDLINE, and Scopus that identified 3478 articles. Of these articles, 10 met inclusion criteria. Random and fixed-effect meta-analyses were performed using both pooled and subset analyses based on study type. RESULTS The meta-analysis demonstrated that CSFD decreased SCI by nearly half (relative risk 0.42, 95% confidence interval 0.25-0.70; p = 0.0009) in the pooled analysis. This effect remained in the subgroup analysis of early SCI but did not remain significant in late SCI. CONCLUSIONS This meta-analysis showed that CSFD could be an effective strategy in preventing SCI following aortic aneurysm repair. Care should be taken to prevent complications related to overdrainage. No firm conclusions can be drawn about the newer endovascular procedures at the current time.

Remote Ischemic Preconditioning May Attenuate Renal Ischemia-Reperfusion Injury in a Porcine Model of Supraceliac Aortic Cross-Clamping

AIM

The effect of remote ischemic preconditioning (RIPC) in decreasing renal ischemia-reperfusion injury (IRI) during a suprarenal aortic cross-clamping was examined in a swine model.

MATERIALS AND METHODS

Four groups of pigs were examined: (a) ischemia-reperfusion (IR) group, renal IRI produced by 30 min of supraceliac aortic cross-clamping; (b) RIPC I group, the same renal IRI following RIPC by brief occlusion of the infrarenal aorta (15 min ischemia and 15 min reperfusion); (c) RIPC II group, the same renal IRI following RIPC by brief occlusion of the infrarenal aorta (3 cycles of 5 min ischemia and 5 min reperfusion); (d) sham group. Renal function was assessed before and after IRI by examining creatinine, neutrophil gelatinase-associated lipocalin (NGAL), TNF-α, malondialdehyde (MDA), cystatin C and C-reactive protein (CRP) from renal vein blood samples at specific time intervals.

RESULTS

Both RIPC groups presented significantly less impaired results compared to the IR group when considering MDA, cystatin C, CRP and creatinine. Between the two RIPC groups, RIPC II presented a better response with regard to CRP, NGAL, TNF-α, MDA and cystatin C.

CONCLUSIONS

Remote IR protocols and mainly repetitive short periods of cycles of IR ameliorate the biochemical kidney effects of IRI in a model of suprarenal aortic aneurysm repair.

Functional outcome after resuscitative endovascular balloon occlusion of the aorta of the proximal and distal thoracic aorta in a swine model of controlled hemorrhage

BACKGROUND

Noncompressible torso hemorrhage remains an ongoing problem for both military and civilian trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been characterized as a potentially life-saving maneuver. The objective of this study was to determine the functional outcomes, paraplegia rates, and survival of 60-min balloon occlusion in the proximal and distal thoracic aorta in a porcine model of controlled hemorrhage.

METHODS

Swine (Sus scrofa, 70-110 kg) were subjected to class IV hemorrhagic shock and underwent 60 min of REBOA. Devices were introduced from the left carotid artery and positioned in the thoracic aorta in either the proximal location (pREBOA [n = 8]; just past takeoff of left subclavian artery) or distal location (dREBOA [n = 8]; just above diaphragm). After REBOA, animals were resuscitated with whole blood, crystalloid, and vasopressors before a 4-day postoperative period. End points included evidence of spinal cord ischemia (clinical examination, Tarlov gait score, bowel and bladder dysfunction, and histopathology), gross ischemia-reperfusion injury (clinical examination and histopathology), and mortality.

RESULTS

The overall mortality was similar between pREBOA and dREBOA groups at 37.5% (n = 3). Spinal cord-related mortality was 12.5% for both pREBOA and dREBOA groups. Spinal cord symptoms without death were present in 12.5% of pREBOA and dREBOA groups. Average gait scores improved throughout the postoperative period.

CONCLUSIONS

REBOA placement in the proximal or distal thoracic aorta does not alter mortality or paraplegia rates as compared with controlled hemorrhage alone. Functional recovery improves in the presence or the absence of REBOA, although at a slower rate after REBOA as compared with negative controls. Additional research is required to determine the ideal placement of REBOA in an uncontrolled hemorrhage model to achieve use compatible with survival outcomes and quality of life.

Targeted chelation therapy with EDTA-loaded albumin nanoparticles regresses arterial calcification without causing systemic side effects

BACKGROUND AND AIMS

Elastin-specific medial arterial calcification (MAC) is an arterial disease commonly referred as Monckeberg's sclerosis. It causes significant arterial stiffness, and as yet, no clinical therapy exists to prevent or reverse it. We developed albumin nanoparticles (NPs) loaded with disodium ethylene diaminetetraacetic acid (EDTA) that were designed to target calcified elastic lamina when administrated by intravenous injection.

METHODS AND RESULTS

We optimized NP size, charge, and EDTA-loading efficiency (150-200 nm, zeta potential of -22.89--31.72 mV, loading efficiency for EDTA~20%) for in vivo targeting in rats. These NPs released EDTA slowly for up to 5 days. In both ex-vivo study and in vivo study with injury-induced local abdominal aortic calcification, we showed that elastin antibody-coated and EDTA-loaded albumin NPs targeted the damaged elastic lamina while sparing healthy artery. Intravenous NP injections reversed elastin-specific MAC in rats after four injections over a 2-week period. EDTA-loaded albumin NPs did not cause the side effects observed in EDTA injection alone, such as decrease in serum calcium (Ca), increase in urine Ca, or toxicity to kidney. There was no bone loss in any treated groups.

CONCLUSION

We demonstrate that elastin antibody-coated and EDTA-loaded albumin NPs might be a promising nanoparticle therapy to reverse elastin-specific MAC and circumvent side effects associated with systemic EDTA chelation therapy.

Predictors of paraplegia with current thoracoabdominal aortic aneurysm repair

Background

Although the results of surgical repair of thoracoabdominal aortic aneurysm continue to improve, the incidence of paraplegia remains within a wide range depending on each institution. The purpose of this study was to find predictors of paraplegia following thoracoabdominal aortic aneurysm repair in our institute, using the current spinal cord protection strategies.

Methods

From January 2007 to December 2011, 200 consecutive patients underwent thoracoabdominal aortic aneurysm repair. Of these, 24 (12%) had Crawford extent I repair, 82 (41%) had extent II, 51 (25.5%) had extent III, 10 (5%) had extent IV, and 33 (16.5%) had extent V (modified by Safi). Aortic dissection was present in 101 (50.5%) patients. Adjuncts used during the procedures included left heart bypass in all patients, cerebrospinal fluid drainage in 164 (82%), and intercostal artery reimplantation in 76 (38%).

Results

There were 20 (10%) hospital deaths including 6 (3%) within 30 days; hospital mortality was 8.8% in elective operations. Postoperative complications included paraplegia in 17 (8.5%) patients, stroke in 5 (2.5%), and acute renal failure requiring dialysis in 5 (2.5%). Logistic regression analysis revealed that significant factors for the development of paraplegia were preoperative hypotension ( p = 0.005, odds ratio 18.5), intraoperative hypotension ( p = 0.001, odds ratio 77.6), and an open distal anastomosis technique ( p = 0.012, odds ratio 4.6).

Conclusions

The predictors of postoperative paraplegia in our institution were perioperative hypotension and an open distal anastomosis technique. Avoidance of these risk factors might diminish the incidence of postoperative paraplegia.

Hospital volume of thoracoabdominal aneurysm repair does not affect mortality in California

OBJECTIVES

Open thoracoabdominal aneurysm repair (TAAR) is a rarely performed but a complicated and morbid procedure. This study compares the morbidity and mortality of open TAAR at high- versus low-volume hospitals.

METHODS

Included patients from California Office of Statewide Health Policy and Development patient discharge database who underwent an open TAAR between 1995 and 2010. High volume was ≥ 9 cases per year. Outcomes included mortality and postoperative complications. Multivariate analyses compared patients at high- versus low-volume hospitals.

RESULTS

A total of 122 hospitals were included, with 5 designated as high volume. Adjusted analysis found no difference in the odds ratio (OR) of mortality or morbidity at high-volume hospitals compared to low-volume hospitals (OR 0.37, P = .077; OR 0.94, P = .834, respectively). However, there was a decreased OR of mortality in high- versus low-volume hospitals when a high-volume hospital was defined as each year after meeting the initial threshold of 9 cases (OR 0.40, P = .040).

CONCLUSION

We found no difference in mortality between low- and high-volume institutions in California, until high-volume hospitals were defined as each year after meeting initial threshold case volume. This may suggest that the benefits of high-volume hospitals on outcomes are maintained after reaching the requisite case volume.

Paraplegia prevention by oral pretreatment with memantine in a rabbit model

OBJECTIVE

To evaluate the role of memantine (N-methyl-d-aspartate receptor antagonist) pretreatment for the prevention of spinal cord ischemia after infrarenal aortic clamping in a rabbit model.

METHODS

Thirty New Zealand White rabbits were divided into 5 different groups of 6 rabbits. Groups 60-7 and 60-5 received oral memantine 60 mg once a day for 7 and 5 days, respectively, and groups 30-5 and 30-3 received oral memantine 30 mg once a day for 5 and 3 days, respectively, all before surgery. Group C (control) received normal feeds without memantine. A paraplegic model was created by clamping both the aorta and the inferior vena cava infrarenally and just proximal to their bifurcations for 45 minutes. The modified Tarlov score, motor evoked potential (MEP), serum memantine concentration, and histopathology of the spinal cord were evaluated.

RESULTS

The mean modified Tarlov scores were 4.2±1.3, 4.3±1.0, 4.2±1.3, 4.3±1.2, and 0.8±1.6 in groups 60-7, 60-5, 30-5, 30-3, and C, respectively at 6, 24, 48, and 72 hours (P<.009 for individual groups vs control). Percentage amplitude loss of MEP by the end of surgery was 29.5%±46.3%, 11.9%±28.0%, 30.0%±46.8%, 16.7%±40.8%, and 81.8%±40.3% for the 5 groups, respectively (P=.049). After declamping, MEP reappeared in 83%, 100%, 83%, 83%, and 33% of cases in the 5 groups, respectively (P=.073). The serum memantine level was similar in the 4 memantine groups. Spinal cords were normal in most of the rabbits in groups 60-7, 60-5, 30-5, and 30-3, but severely ischemic in most of the rabbits in group C (P=.041).

CONCLUSIONS

Oral memantine pretreatment is protective against spinal cord ischemia, and can be an additional strategy for the prevention of paraplegia during thoracoabdominal aortic surgeries.

Ortner's syndrome

A 42-year-old man with a significant smoking history presented with chronic expectorative cough and exertional shortness of breath with recent-onset hoarseness. Chest examination was essentially normal and cardiovascular examination was suggestive of aortic regurgitation. Ears, nose and throat evaluation showed left vocal cord palsy and CT scan revealed an aortic arch aneurysm. Ortner's syndrome refers to hoarseness due to recurrent laryngeal nerve palsy secondary to a cardiovascular abnormality. Aortic aneurysms usually present with chest pain, back pain or epigastric pain, depending on the site of the aneurysm. An aortic arch aneurysm presenting as hoarseness is extremely rare.

Impact of aortic cross-clamping time on peripheral nerves: experimental model

PURPOSE

The present study investigated the correlation between extend aortic cross-clamping time and peripheral nerve injury on rats.

METHODS

24 male, Sprague Dawley rats were divided into 3 groups; (a) control group: abdomen was directly closed after reached aorta, and followed by 72 hours, (b) short-term ischaemia-reperfusion group: peripheral nerve ischemia was induced in rats by supraceliac aortic occlusion for 20 min followed by 72 h of reperfusion, (c) long-term ischaemia-reperfusion group: peripheral nerve ischemia was induced for 30 min followed by 72 h of reperfusion. Preoperative and postoperative, electromyography (EMG) recordings were done. End of 72 h, the sciatic nerves were harvested from each animal for histopathological and biochemical analysis.

RESULTS

The mean compound muscle action potential (CMAP) amplitude of long-term ischaemia-reperfusion group was statically significant reduced when compared to the control group (p <0.01). However, the mean distal latency value of long-term ischaemia-reperfusion group was statically significant increased (p <0.01). On the other hand, there were statically significant differences between the results of malondialdehyde, edema and ischemia fiber degeneration grades on control and long-term ischaemia-reperfusion group (p <0.001).

CONCLUSION

This study demonstrated that the extending cross clamping time directly harms the peripheral nerve of rats.

Clinical outcomes of hybrid repair for thoracoabdominal aortic aneurysms

BACKGROUND

Thoracoabdominal aortic aneurysm (TAAA) hybrid repair consists of aortic visceral branch rerouting followed by TAAA endograft exclusion. This technique has been shown to represent a technically feasible strategy in selected patients.

METHODS

We analyzed 52 high-risk patients who underwent hybrid TAAA repair between 2001 and 2012 in our centre with a variety of visceral rerouting configurations and of commercially available thoracic endografts. Thirty-seven simultaneous (71.2%) and 15 staged procedures (21.8%) were performed with a four-vessel revascularization in 18 cases (34.6%), a three-vessel revascularization in 11 cases (21.2%) and a two-vessel revascularization in 23 cases (44.2%).

RESULTS

No intraoperative deaths were observed. We recorded a perioperative mortality rate of 13.5% (n=7), including deaths from multiorgan failure (n=2), myocardial infarction (n=2), coagulopathy (n=1), pancreatitis (n=1) and bowel infarction (n=1). Perioperative morbidity rate was 28.8% (n=15), including 2 cases of transient paraparesis and 1 case of permanent paraplegia. Renal failure (n=5), pancreatitis (n=3), respiratory failure (n=3) and dysphagia (n=1) were also observed. At median follow-up of 23.9 months procedure-related mortality rate was 9.6%: two patients died from visceral graft occlusion and three from aortic rupture. There were three endoleaks and one endograft migration, none of which resulted in death. Five patients (9.6%) died as a consequence of unrelated events.

CONCLUSIONS

Typical complications of conventional TAAA open surgery have not been eliminated by hybrid repair, and significant mortality and morbidity rates have been recorded. Fate of visceral bypasses and incidence of endoleak and other endograft-related complications needs to be carefully assessed. Hybrid TAAA repair should currently be limited to high-risk surgical patients with unfit anatomy for endovascular repair.

Thoracic endovascular aortic repair: update on indications and guidelines

Thoracic endovascular aortic repair (TEVAR) has revolutionized thoracic aortic surgery and has increased the options available to the aortic specialist in treating thoracic aortic disease. TEVAR is less invasive, and is associated with a decrease in perioperative morbidity and mortality when compared with open surgical repair. The dramatic expansion of TEVAR activity has necessitated a better definition for the indications, contraindications, and limitations of this new technology. Ideally TEVAR should be performed in specialized aortic centers providing a full range of diagnostic and treatment options, using a multidisciplinary team approach.

Hybrid repair of simultaneous multiple mycotic aortic aneurysms

Simultaneous mycotic aortic aneurysms are a rare but life-threatening complication. We describe the technique of one stage hybrid open debranching and endovascular repair using three thoracic stent-graft devices deployed to cover the whole aorta to exclude multiple mycotic aneurysms.

Tratamento endovascular das doenças da aorta torácica: análise dos resultados de um centro

OBJETIVO: Analisar os resultados do tratamento de uma série consecutiva de pacientes submetidos a tratamento endovascular de doenças da aorta torácica. Foram observados o sucesso técnico, o sucesso terapêutico, a morbimortalidade e a taxa de complicações perioperatórias e de reintervenções. MATERIAIS E MÉTODOS: Estudo retrospectivo, realizado em um centro de referência, no período de janeiro de 2010 a julho de 2011, em que foram analisados pacientes submetidos a correção endovascular de doenças da aorta torácica. A população foi dividida em dois grupos: grupo 1 (G1) - aneurismas de aorta torácica verdadeiros, úlcera aórtica e pseudoaneurisma; grupo 2 (G2) - dissecção aórtica tipo B crônica. RESULTADOS: Em um total de 55 pacientes tratados, 29 pertenciam ao G1 e 26, ao G2. As idades médias foram 66,8 ± 10 e 56,4 ± 7 anos, respectivamente. Os sucessos técnico e terapêutico foram, respectivamente, 86,3% e 68,6% no G1 e 100% e 74% no G2. A mortalidade perioperatória foi 10,3% no G1 e 7,6% no G2, com taxa de mortalidade anual de 10,3% no G1 e de 19,3% no G2. As taxas de reintervenções foram 10,3% e 15,3%, respectivamente. CONCLUSÃO: Em nosso estudo, o tratamento endovascular das doenças da aorta torácica demonstrou ser um método viável e associado a aceitáveis taxas de complicações.

[Transient delayed paraplegia after repair of thoracic and thoracoabdominal aneurysms]

Thoracoabdominal aneurysm requires multidisciplinary management due to its complexity both in surgical technique and anesthetic considerations. One of the most feared postoperative complication is spinal cord ischemia. It can be presented as different clinical patterns, and its recovery may be partial or complete. The postoperative management of spinal cord ischemia is mainly based on techniques to increase spinal cord perfusion, above all, hemodynamic stability and cerebrospinal fluid drainage. We present two cases of delayed paraplegia after an open repair of a thoracoabdominal aneurysm and a descending thoracic aortic aneurysm repair using an endovascular stent graft. They both had a complete neurological recovery after cerebrospinal fluid drainage.

Distal aortic perfusion during thoracoabdominal aneurysm repair for prevention of paraplegia

BACKGROUND

During thoracoabdominal aortic aneurysm (TAAA) surgery, decreased spinal cord perfusion can result in neurological deficits such as paraplegia and paraparesis. Distal aortic perfusion, alone or in combination with other adjuncts, may counter the decrease in spinal cord perfusion and hence reduce the risk of spinal cord injury.

OBJECTIVES

To determine the effectiveness of distal aortic perfusion with or without other adjuncts against other adjuncts without use of distal perfusion during TAAA surgery in reducing the risk of developing paraplegia and paraparesis.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Specialised Register (last searched 5 January 2012) and CENTRAL (Issue 4, 2011) were searched for publications describing randomised controlled trials of distal aortic perfusion during thoracoabdominal aortic aneurysm surgery. Reference lists of relevant studies were checked.

SELECTION CRITERIA

Randomised or quasi-randomised controlled clinical trials of distal aortic perfusion during TAAA repair.

DATA COLLECTION AND ANALYSIS

Studies identified for potential inclusion were independently assessed for inclusion by at least two authors, with excluded trials arbitrated by the third author.

MAIN RESULTS

There were no randomised controlled trials identified.

AUTHORS' CONCLUSIONS

Currently, there are no randomised controlled trials to support the role of distal aortic perfusion in TAAA surgery for prevention of neurological injury. However, randomised controlled trials are not always feasible based on ethical grounds. Observational studies suggest that distal aortic perfusion alone or in combination with other adjuncts, that is cerebrospinal fluid (CSF) drainage, reduces the rate of neurologic deficit across all types of TAAA; in particular making a striking difference in the rate of neurologic deficit following type II TAAA repair. In the absence of randomised controlled trials, we recommend a standardised approach to reporting through registry studies to strengthen the evidence base for distal aortic perfusion.

Changes of motor evoked potentials during descending thoracic and thoracoabdominal aortic surgery with deep hypothermic circulatory arrest

BACKGROUND

Paraplegia is a serious complication of descending and thoracoabdominal aortic aneurysms (dTAAs and TAAAs) surgery. Motor evoked potentials (MEPs) enable monitoring the functional integrity of motor pathways during dTAA and TAAA surgery. Although MEPs are sensitive to temperature changes, there are few human data on changes of MEPs during mild and deep hypothermia. Therefore, we investigated changes of MEPs in deep hypothermic circulatory arrest (DHCA) in dTAA and TAAA surgery.

METHODS

Fifteen consecutive patients undergoing dTAA and TAAA surgery using DHCA were enrolled. MEPs were elicited and recorded during each degree Celsius change in nasopharyngeal temperature during both the cooling and rewarming phases. Hand and leg skin temperature were also recorded simultaneously.

RESULTS

In the cooling phase MEP amplitude decreased lineally in both the hand and leg. The MEP disappeared at ~16°C in both the hand and leg in 10 of 15 patients, but was still elicited in 5 patients. In the rewarming phase MEP in the hand recovered before the temperature reached 20°C for eight patients and 25°C for the other seven patients. In contrast, MEP in the leg recovered below 20°C for two patients and 30°C for three patients. For the other eight patients MEP waves did not recover during the rewarming phase.

CONCLUSION

In the cooling phase of DHCA, MEP disappeared at ~16°C in some patients but was still elicited in others. MEP recovered below 25°C in the hand. Recovery of MEP in the leg was, however, extremely variable.

Subarachnoid hemorrhage due to retained lumbar drain

Intrathecal spinal catheters (lumbar drains) are indicated for several medical and surgical conditions. In neurosurgical procedures, they are used to reduce intracranial and intrathecal pressures by diverting CSF. They have also been placed for therapeutic access to administer drugs, and more recently, vascular surgeons have used them to improve spinal cord perfusion during the treatment of thoracic aortic aneurysms. Insertion of these lumbar drains is not without attendant complications. One complication is the shearing of the distal end of the catheter with a resultant retained fragment. The authors report the case of a 65-year-old man who presented with a subarachnoid hemorrhage due to the migration of a retained lumbar drain that sheared off during its removal. To the best of the authors' knowledge, this is the first case of rostral migration of a retained intrathecal catheter causing subarachnoid hemorrhage. The authors review the literature on retained intrathecal spinal catheters, and their findings support either early removal of easily accessible catheters or close monitoring with serial imaging.