Outcomes in open repair of the thoracic and thoracoabdominal aorta

Triple-Branched Stent Graft Implantation for Acute Non-A-non-B Aortic Dissection

BACKGROUND

The optimal treatment for acute non-A-non-B aortic dissection remains controversial. Triple-branched stent graft (TBSG) implantation has been used to treat acute type A aortic dissection. This study aimed to evaluate the safety and efficacy of TBSG as a treatment for acute non-A-non-B aortic dissection.

METHODS

Fifty patients with non-A-non-B dissection received TBSG implantation in our center between January 2014 and December 2019. Early mortality, morbidity, and dissected aorta remodeling during follow-up were calculated.

RESULTS

There were no deaths in-hospital or within 30 days. Postoperative complications included pneumonia (n = 12), acute kidney injury (n = 6; preoperative renal malperfusion, n = 4), transient cerebral injury (n = 6; preoperative cerebral malperfusion, n = 4), pleural effusion (n = 4), and pericardial effusion (n = 2). During follow-up, 1 patient experienced a stroke, and 2 patients required secondary interventional therapy for residual dissection below the level of the TBSG. All implanted TBSGs had good positioning, and all sidearm stent graft grafts were fully patent. No retrograde aortic dissection or type I endoleak was detected.

CONCLUSIONS

TBSG implantation for acute non-A-non-B aortic dissection had a low incidence of mortality and morbidity, featuring good remodeling of the dissected aortic wall during follow-up. The early outcomes of this technique were satisfactory.

Spinal drain for aortic aneurysm repairs: tool or toy?

PURPOSE OF REVIEW

Spinal cord injury (SCI) is one of the biggest complications in open and endovascular aortic repairs. Historically, cerebrospinal fluid drains (CSFD) have been one of the most effective modalities in reducing SCI and one of the most studied. CSFD placement also carries its' own set of procedural risks. This editorial intends to evaluate recent literature to determine whether CSFDs remain a valuable tool in aortic repair.

RECENT FINDINGS

As the surgical management of thoracic aortic aneurysms has evolved, there has been an increasing number of endovascular repairs. Current recommendations emphasize prophylactic CSFD placement in endovascular repair cases deemed 'high risk.' However, several meta-analyses differ on whether prophylactic CSFD placement reduced the risk of SCI. The incidence of SCI decreased between 2014 and 2018, despite a similar rate of prophylactic CSFD placement suggesting other techniques are being performed and may be effective in spinal cord protection as well.

SUMMARY

There has been conflicting data on whether CSFDs have a role in reducing the risk of SCI in endovascular aortic repair. Some studies suggest that there is no benefit to placement while others suggest that routine prophylactic drains should be placed for all endovascular cases. Despite this, efforts have been made to selectively place CSFDs in those patients deemed at 'high risk' for SCI. CSFDs also remain a part of rescue treatment for postoperative SCI. This suggests that CSFDs continue to be a valuable tool that we need to better comprehend. Future research is necessary to better understand how patient risk factors can be balanced with perioperative management to help identify patients who may benefit from CSFD placement.

Postoperative Intensive Care Management of Aortic Repair

Vascular surgery patients have multiple comorbidities and are at high risk for perioperative complications. Aortic repair surgery has greatly evolved in recent years, with an increasing predominance of endovascular techniques (EVAR). The incidence of cardiac complications is significantly reduced with endovascular repair, but high-risk patients require postoperative ST-segment monitoring. Open aortic repair may portend a prohibitive risk of respiratory complications that could be a contraindication for surgery. This risk is greatly reduced in the case of an endovascular approach, and general anesthesia should be avoided whenever possible in the case of endovascular repair. Preoperative renal function and postoperative kidney injury are powerful determinants of short- and long-term outcome, so that preoperative risk stratification and secondary prevention are critical tasks. Intraoperative renal protection with selective renal and distal aortic perfusion is essential during open repair. EVAR has lower rates of postoperative renal failure compared to open repair, with approximately half the risk for acute kidney injury (AKI) and one-third of the risk of hemodialysis requirement. Spinal cord ischemia used to be the most distinctive and feared complication of aortic repair. The risk has significantly decreased since the beginning of aortic surgery, with advances in surgical technique and spinal protection protocols, and is lower with endovascular repair. Endovascular repair avoids extensive aortic dissection and aortic cross-clamping and is generally associated with reduced blood loss and less coagulopathy. The intensive care physician must be aware that aortic repair surgery has an impact on every organ system, and the importance of early recognition of organ failure cannot be overemphasized.

Physician-Modified TEVAR versus Hybrid Repair of the Proximal Descending Thoracic Aorta

There are different surgical options for the treatment of proximal lesions of the descending thoracic aorta. The aim of this study was to compare the outcome of physician-modified TEVAR (pmTEVAR) vs. hybrid repair of the thoracic aorta in terms of TEVAR with carotid-subclavian bypass (hdTEVAR). This was a single-centre, retrospective comparative study of all patients who underwent pmTEVAR and hybrid repair of the proximal descending aorta from January 2018 to June 2021. Primary outcomes were technical success, 30-day mortality, perioperative stroke, 30-day reinterventions and supraaortic access related complications. Secondary outcomes were patient survival, late complications, late reinterventions, and bypass/bridging stent patency. A total of 181 patients underwent TEVAR within the period of 42 months. In our study, only patients with proximal landing in zone 2 (n = 39) were included. A total of 5 of 15 pmTEVAR and 8 of 24 hybrid repair operations (33% vs. 33%, respectively) were performed due to aneurysms. Among the rest of the patients, 10 of 15 pmTEVAR and 16 of 24 hybrid operations (67% vs. 67%) were performed due to aortic dissection. Technical success was achieved in 100% of the patients. No significant difference in terms of postoperative complications could be detected in the early and midterm follow up period. The 30-day mortality was 12.5% in the hybrid repair group (n = 3) vs. 6.66% (n = 1) in the pmTEVAR group (p = 0.498). These patients underwent the operation in an emergency setting. No patient died after an elective operation. The causes of early mortality were major stroke (n = 2), haemorrhagic shock (n = 1) in the hybrid group and progredient spinal cord ischemia with tetraplegia and acute respiratory insufficiency (n = 1) in the pmTEVAR group. In conclusion, both therapies are robust techniques, with comparable patency rate and perioperative complications. pmTEVAR appears to be advantageous in terms of operation time and tendency to lower mortality rates.

Endovascular treatment of thoracoabdominal aortic aneurysms

Endovascular repair of thoracoabdominal aneurysms using fenestrated and/or branched stent grafts is technically feasible and efficacious but carries a steep learning curve. This innovative surgical approach is associated with less perioperative morbidity than traditional open repair and its early and mid-term outcomes are very favorable. Spinal cord ischemia remains a devastating complication after these procedures, hence the importance of various neuroprotective strategies. Widespread applicability remains limited in the United States, as no custom-made or off-the-shelf endografts are commercially available. Access to these devices remains limited to physician-sponsored or industry-sponsored clinical trials, but results from the Cook p-Branch and Gore Thoracoabdominal Branch Endoprosthesis trials are on the horizon.

Non-Coding RNAs: Emerging Therapeutic Targets in Spinal Cord Ischemia-Reperfusion Injury

Paralysis or paraplegia caused by transient or permanent spinal cord ischemia–reperfusion injury (SCIRI) remains one of the most devastating post-operative complications after thoracoabdominal aortic surgery, even though perioperative strategies and surgical techniques continue to improve. Uncovering the molecular and cellular pathophysiological processes in SCIRI has become a top priority. Recently, the expression, function, and mechanism of non-coding RNAs (ncRNAs) in various diseases have drawn wide attention. Non-coding RNAs contain a variety of biological functions but do not code for proteins. Previous studies have shown that ncRNAs play a critical role in SCIRI. However, the character of ncRNAs in attenuating SCIRI has not been systematically summarized. This review article will be the first time to assemble the knowledge of ncRNAs regulating apoptosis, inflammation, autophagy, and oxidative stress to attenuate SCIRI. A better understanding of the functional significance of ncRNAs following SCIRI could help us to identify novel therapeutic targets and develop potential therapeutic strategies. All the current research about the function of nRNAs in SCIRI will be summarized one by one in this review.

Sarcopenia predicts for long-term survival in patients with thoracoabdominal aortic aneurysms undergoing operative and nonoperative management

OBJECTIVE

Sarcopenia, defined as a loss of muscle mass or poor muscle quality, is a syndrome associated with poor surgical outcomes. The prognostic value of sarcopenia in patients with thoracoabdominal aortic aneurysms (TAAAs) is unknown. The present study was designed to define sarcopenia in this patient population and assess its impact on survival among patients who had undergone operative and nonoperative management of TAAAs.

METHODS

We retrospectively reviewed all patients with a diagnosis of a TAAA at an academic hospital between 2009 and 2017 who had been selected for operative and nonoperative management. Sarcopenia was identified by measuring the total muscle area on a single axial computed tomography image at the third lumbar vertebra. The muscle areas were normalized by patient height, and cutoff values for sarcopenia were established at the lowest tertile of the normalized total muscle area. Long-term patient survival was assessed using Kaplan-Meier and Cox regression models.

RESULTS

A total of 295 patients were identified, of whom 199 had undergone operative management and 96 nonoperative management for TAAAs. The patients selected for nonoperative management were more likely to be women and to have chronic kidney disease, coronary artery disease, cerebrovascular disease, a higher modified frailty index, and a larger aortic diameter. The Kaplan-Meier analyses revealed significantly lower long-term survival for the patients with and without sarcopenia in the operative and nonoperative groups. In Cox regression analyses, sarcopenia was a significant predictor of shorter survival for both operative (hazard ratio, 0.96; 95% confidence interval, 0.94-0.99; P = .006) and nonoperative (hazard ratio, 0.95; 95% confidence interval, 0.90-1.00; P = .05) groups after adjusting for age, race, sex, maximum aortic diameter, modified frailty index, chronic kidney disease, and active smoking. Additionally, age was a significant predictor of shorter survival in the operative group, and smoking and aortic diameter were significant in the nonoperative group.

CONCLUSIONS

In our cohort of patients who had received operative and nonoperative management of TAAAs, the patients with sarcopenia had had significantly lower long-term survival, regardless of whether surgery had been performed. These data suggest that sarcopenia could be used as a predictor of survival for patients with TAAAs and might be useful for risk stratification and decision making in the management of TAAAs.

Prognostication of Asymptomatic Penetrating Aortic Ulcers: A Modern Approach

Background: Literature detailing the natural history of asymptomatic penetrating aortic ulcers (PAU) is sparse and lacks long-term follow-up. This study sought to determine the rate of asymptomatic PAU growth over time and adverse events from asymptomatic PAU. Methods: A cohort of patients with asymptomatic PAU from 2005-2020 was followed. One ulcer was followed per patient. Primary endpoints were change in size over time and the composite of symptoms, radiographic progression, rupture, and intervention; cumulative incidence function estimated the incidence of the composite outcome. Ulcer size and rate of change were modeled using a linear mixed effects model. Patient and anatomic factors were evaluated as potential predictors of the outcomes. Results: There were 273 patients identified. Mean age was 75.5±9.6 years; 66.4% were male. The majority of ulcers were in the descending thoracic aorta (53.9%), followed by abdominal aorta (41.4%), and aortic arch (4.8%). Fusiform aneurysmal disease was present in 21.6% of patients at a separate location; 2.6% had an associated intramural hematoma; 23.6% had at least one other PAU. Symptoms developed in one patient who ruptured; 8 patients (2.9%) underwent an intervention for PAU (one for rupture, 2 for radiographic progression, 5 for size/growth) at a median of 3.1 years (IQR:1.0-6.5) after diagnosis. Five and 10-year cumulative incidence of the primary outcome, adjusted for competing risk of death, was 3.6% (95% CI: 1.6-6.9%) and 6.5% (95% CI: 3.1-11.4%), respectively. For 191 patients with multiple CT scans (760 total CT's) with median radiographic follow-up of 3.50 years (IQR:1.20-6.63 years), mean initial ulcer width, ulcer depth, and total diameter in millimeters (mm) was 13.6, 8.5, and 31.4, respectively. Small, but statistically significant change over time was observed for ulcer width (0.23 mm/year) and total diameter (0.24 mm/year); ulcer depth did not significantly change over time. Hypertension, hyperlipidemia, diabetes, initial ulcer width>20 mm, thrombosed PAU, and associated saccular aneurysm were associated with larger changes in ulcer size over time, however the magnitude of difference was small, ranging from 0.4-1.9 mm/year. Conclusions: Asymptomatic PAU displayed minimal growth and infrequent complications including rupture. Asymptomatic PAU may be conservatively managed with serial imaging and risk-factor modification.

Spinal Cord Protection for Thoracoabdominal Aortic Surgery

Open and endovascular repairs of the descending thoracic and thoracoabdominal aorta are associated with a substantial risk of spinal cord injury, namely paraplegia. Endovascular repairs seem to have a lower incidence of spinal cord injury, but there have been no randomized trials comparing outcomes of open and endovascular repairs. Paraplegia occurs when collateral blood supply to the anterior spinal artery is impaired. The risk of spinal cord injury can be mitigated with perioperative protocols that include drainage of cerebrospinal fluid, avoidance of hypotension and anemia, intraoperative neurophysiologic monitoring, and advanced surgical techniques. Drainage of cerebrospinal fluid using a spinal drain decreases the risk of spinal cord ischemia by improving spinal cord perfusion pressure. However, cerebrospinal fluid drainage has risks including neuraxial and intracranial bleeding, and these risks need to be carefully weighed against its potential benefit. This review discusses current surgical management of descending thoracic and thoracoabdominal aortic disease, incidence of and risk factors for spinal cord injury, and elements of spinal cord protection protocols that pertain to anesthesiologists, with a focus on cerebrospinal fluid drainage.

Long-term survival after descending thoracic and thoracoabdominal aortic aneurysm repair

OBJECTIVE

Patients with descending thoracic aortic aneurysms (dTAA) or thoracoabdominal aortic aneurysms (TAAA) often have a variety of medical comorbidities. Those that are deemed acceptable for intervention undergo complicated repairs with good early outcomes. The purpose of this study was to identify variables that were associated with mortality over time.

METHODS

This was a retrospective review of a prospectively maintained database at our institution from 1983 to 2015. Patients were included if they underwent open or endovascular repair for dTAA or TAAA. Patients were excluded if they were intervened on for traumatic transections. The primary outcome for the study was long-term survival. Secondary outcomes included aortic-related mortality. We had mortality and survival data on all patients.

RESULTS

A total of 946 patients met our study criteria with a median follow-up of 102.8 months (interquartile range [IQR], 58.9-148.2 months). The median age of the cohort was 71 years (IQR, 63-77 years) with the majority of patients being male (58.1%). The extent of TAAA pathology was as follows: type I (14.2%), type II (21.2%), type III (17.1%), type IV (26.2%), and dTAA (21.2%). A total of 147 patients (15.5%) had a prior dissection. The median diameter of aneurysm was 6.4 cm (IQR, 6.0-7.0 cm). A total of 158 patients (16.7%) underwent endovascular repair over the study period. Variables associated with mortality over time were age, surgical era, acute pathology, dissection, preoperative creatinine, and type IV TAAAs. In addition, experiencing the following complications in the postoperative period was associated with mortality over time: neurological, cardiac, and pulmonary. Aortic-related mortality was 2.1% (n = 20) over the study period. Patients who underwent endovascular repair for acute conditions had better long-term survival when compared with open repair. However, there were no differences in long-term survival between open and endovascular repair for nonacute cases. In addition, repair in the more modern era was associated with improved survival.

CONCLUSIONS

TAAAs can be repaired with reasonable perioperative mortality rates. Once patients undergo repair of their aneurysm, aortic-related mortality remains low. The addition of endovascular options has dramatically changed management of patients with dTAA and TAAA. Further, endovascular repair was associated with decreased perioperative mortality and significantly increased long-term survival in acute patients. Patients undergoing TAAA repair are generally considered high risk and therefore require extensive long-term follow-up for management of their comorbidities and complications, because these are the main contributors to mortality over time.

Remote Ischemic Preconditioning in Spinal Cord Protection: A Surviving Porcine Study

Surgical repair of thoracic aorta can compromise blood flow of the spinal cord. To mitigate spinal cord ischemia (SCI) additional protection methods are needed. In experimental studies remote ischemic preconditioning (RIPC) has proven to be an effective method of protecting organs from ischemia. The aim of the study was to assess efficacy of RIPC in spinal cord protection in a chronic porcine model. Sixteen piglets were assigned into the RIPC group (8) and the control group (8). RIPC was performed using blood pressure cuff in a 5-minute ischemia followed by a 5-minute reperfusion repeating cycles 4 times. The left subclavian artery and all segmental arteries above diaphragm were ligated at 5-minute intervals to accomplish SCI. The follow-up comprised a 4-hour intensive monitoring and a 7-day recovery phase. Blood samples were obtained, motor-evoked potentials and near-infrared spectroscopy (NIRS) of longitudinal back muscles were measured. Paraplegia was assessed every day postoperatively. Histopathological analysis of the spinal cord was performed after 7 days. NIRS values 4 hours after SCI were higher in the RIPC group, 45.5 (44.5-47.0), than in the control group, 41.5 (40.5-44.0) (P = 0.042). Nadir value of NIRS was 43.4 (39.3-46.0) in the RIPC group and 38.9 (38.-40.0) in the control group (P = 0.014). On the first postoperative day the RIPC group reached modified Tarlov score of 3 (2-3) vs 2 (1-2) in the control group (P = 0.024). RIPC hastens the recovery from SCI during the first postoperative day.

Transplantation of viable mitochondria attenuates neurologic injury after spinal cord ischemia

OBJECTIVES

Spinal cord ischemia (SCI) is one of the major concerns of postoperative paraplegia during major vascular or aortic surgery. Since mitochondrial dysfunction develops at the early stage of SCI, this study tested the neuronal protective effect of transplantation of viable mitochondria to the ischemic cord in rats.

METHODS

SCI was induced by crossclamping of thoracic aorta at T6 level for 25 minutes, followed by release of vascular clip to restore aortic blood flow in the anesthetized rats. Mitochondria (100 μg) were isolated from freshly harvested soleus muscle and delivered via the internal jugular vein before releasing of vascular clip. The motor function was assessed independently up to 7 days after reperfusion. Spinal cords were harvested and analyzed for molecular and histological changes.

RESULTS

Whole-body in vivo images acquired by an in vivo imaging system confirmed the enhancement of MitoTracker fluorescence at the regions below crossclamping and in the ischemic cord. Compared with control vehicles, transplantation of mitochondria significantly improved the lower-limb locomotor function of rats subjected to cord ischemia up to 7 days after surgery. Mitochondrial transplantation suppressed the regional endoplasmic reticulum stress in the ischemic cord by attenuating CCAAT-enhancer-binding protein homologous protein expression and restoring binding immunoglobulin protein levels. In accordance, tissue levels of interleukin-6, tumor necrosis factor-α, and caspase-3 were attenuated in the mitochondrial transplanted group. Histologic examination also showed significant increase in numbers of Nissls bodies in the neurons at the ventral horn of ischemic cord following mitochondrial transplantation.

CONCLUSIONS

Our study showed that transplantation of freshly isolated mitochondria during the early stage of spinal cord ischemia-reperfusion injury suppressed the oxidative stress in endoplasmic reticulum of the injured cord, thereby reducing neuroapoptosis and improving locomotor function of rats with SCI.

Protective role of astragalus injection in spinal cord ischemia-reperfusion injury in rats

Objectives:

To investigate the neuroprotective effect of Astragalus injection in a spinal cord ischemia-reperfusion (I/R) injury model.

Methods:

A total of 27 Sprague Dawley rats were randomly divided into 3 groups: control group (n=3), I/R group (n=12), and Astragalus injection group (Ast group, n=12). Spinal cord ischemia was induced by occlusion of the abdominal aorta above the right renal artery for 32 min. Animals in the Ast group were administered Astragalus injection (6.42 mL/kg) at 30 min before the induction of ischemia. After reperfusion for 8, 12, 24, or 48 hours, the serum neuron-specific enolase (NSE) concentration was measured by enzyme-linked immunosorbent assay (ELISA) and the aquaporin-4 (AQP4) protein level was detected by western blotting.

Results:

The pathological changes, as assessed by hematoxylin and eosin (HE) staining, were milder in the spinal cords of the Ast group compared to the I/R group. Enzyme-linked immunosorbent assay demonstrated that the NSE concentration of the Ast group was significantly lower than that of the I/R group (p<0.05). However, the NSE concentrations of the I/R and Ast groups were significantly higher than that of the control group (p=0.05). Additionally, the expression of AQP4 in the Ast group was lower than that of the I/R group at each time point.

Conclusion:

These findings indicate that Astragalus injection has a neuroprotective effect in spinal cord I/R injury by decreasing the AQP4 expression.

Surgery for chronic type B dissection with aneurysmal degeneration

Purpose

Open repair of descending thoracic or thoracoabdominal aortic aneurysm (TAAA) continues to carry a not insignificant operative risk, even in experienced hands. Over the past three decades, there has been considerable improvement in both the mortality and morbidity associated with these procedures. Herein, we describe our operative results and long-term outcomes in patients with chronic type B aortic dissections.

Methods

Review of the aortic surgical database was conducted to identify all consecutive patients who underwent repair of TAAA for chronic type B dissection from May 1997 to March 2018. The primary end point was operative mortality with secondary end points as the composite of major adverse events as well as each of the individual complications.

Results

One hundred and fifty-three patients met inclusion criteria with 54.9% (84/153) having surgery on an elective basis. The mean age was 58.9 years with a majority of male gender-107/153 (69.9%). Eighty-three (54.2%) of the TAAA were extent I, while 36 (23.5%) were extent II and 34 (22.3%) extent III-IV. Operative mortality was 8.5% (13/153) with eight of the deaths in patients who presented with extent II TAAA. On Kaplan-Meier survival analysis, 87.5% (95% confidence interval (CI) 77.9-97.1%) of the elective cohort were alive after 5 years while only 69.9% (CI 55.2-84.6%) of those in need of urgent/emergency intervention survived (p = .039).

Conclusions

In a majority of patients with chronic type B dissections, reproducibly, excellent outcomes can be achieved with relatively low risk of mortality. In the higher risk subsets of patients with extent II TAAA, careful consideration and discussion of expected outcomes will help inform the decision-making process.

Survival and patient-centered outcome in a disease-based observational cohort study of patients with thoracoabdominal aortic aneurysm

BACKGROUND

Much of the literature describing treatment for thoracoabdominal aortic aneurysm (TAAA) consists of operative series reported by centers of excellence. These studies are limited by referral and selection bias and exclude patients who are not candidates for the reported modality of repair. Little is known about the patients who are not referred or selected for repair. For those undergoing intervention, outcomes such as functional status after surgery are rarely reported. In this study, we address these gaps by reporting two primary end points: 1-year survival and a "good" outcome (defined as successful aneurysm exclusion, freedom from permanent loss of organ system function, and return to preoperative functional status after surgery) in a cohort of TAAA patients, including all nonoperative and operative patients, irrespective of treatment modality.

METHODS

A single-institution database was screened by diagnosis codes for TAAA from 2009 to 2017 using the International Classification of Diseases versions 9 and 10. Diagnosis was confirmed by retrospective chart review and computed tomography findings of aneurysmal degeneration ≥3.2 cm of the paravisceral aorta in continuity with aneurysmal aorta meeting standard criteria for repair. Patients <18 years of age and those with mycotic aneurysm were excluded. Patients were either managed nonoperatively or by one of four operative strategies: (i) open; (ii) endovascular with branched endografts; (iii) hybrid, defined as iliovisceral debranching followed by endograft placement; or (iv) partial repair in which the paravisceral segment was intentionally left unaddressed.

RESULTS

Among the entire cohort of 432 patients with TAAA, significant comorbidities were seen in 143 (33%). Forty-seven percent of the patients were managed nonoperatively. Of these, 65% survived to 1 year. A survival benefit was seen in the open, endovascular, and partial, but not hybrid, operative groups compared with the nonoperative group during a 3-year period. Overall 1-year survival was 81%, but only 65% had a good outcome (P = .0016).

CONCLUSIONS

Nearly half of the patients in this inclusive cohort study did not undergo repair despite access to a variety of operative techniques. Many of these patients die in the short term due to high burden of comorbid disease rather than aneurysm rupture. Among those undergoing operation, a notable difference between survival and good outcome was observed. Operation appears to confer a survival advantage among appropriately selected patients with TAAA, but a large proportion are high risk and may not benefit from operative repair due to limited baseline survival and lower probability of good outcome.

Thoracoabdominal Aortic Aneurysm - The Branch First Technique

Surgical management of thoracoabdominal aortic aneurysms is complex. In particular, maintaining adequate spinal cord and reno-visceral protection during the operation can be challenging. We describe here a branch-first technique developed at our institution, endeavoring to minimized renal and visceral organ ischemic time, decrease risk of spinal cord injury, and provide a controlled and uncluttered field in which the surgeon can operate.

A systematic review and meta-analysis of early outcomes after endovascular versus open repair of thoracoabdominal aortic aneurysms

OBJECTIVE

The objective of this study was to compare the early results of endovascular vs open thoracoabdominal aortic aneurysm (TAAA) repair.

METHODS

MEDLINE and Embase were searched for studies from January 2006 to March 2018 that compared endovascular vs open repair of TAAA using branched or fenestrated endografts. Data were subjected to a meta-analysis using a random-effects model. The outcomes of interest included early mortality, spinal cord injury, renal failure requiring dialysis, stroke, and hospital length of stay.

RESULTS

Eight comparative studies met inclusion criteria. There were two retrospective propensity-matched studies, two unadjusted single-center retrospective studies, and four unadjusted national population-based studies. Mortality in the matched studies was equivalent in both groups. Pooled analysis of all unmatched observational studies revealed a survival benefit for endovascular over open repair (relative risk [RR], 0.63; 95% confidence interval [CI],0.45-0.87); P < .01, I² = 47%). Endovascular repair was also associated with lower incidence of spinal cord injury (RR, 0.65; 95% CI, 0.42-1.01; P = .05; I² = 28%). For unmatched studies, pooled RR of renal failure requiring dialysis significantly favored endovascular repair (RR, 0.44; 95% CI, 0.23-0.85; P = .01; I² = 0%), although in the adjusted cohort, risk of dialysis was not different (RR, 1.00; 95% CI, 0.06-15.65; P = 1.00). Postoperative stroke rate was reported in three unadjusted studies and was not different between groups (RR, 0.81; 95% CI, 0.28-2.40; P = .71; I² = 77%). Hospital length of stay was reported in four studies and was shorter in the endovascular group (mean difference, -4.4 days; 95% CI, -6.6 to -1.7; P < .01; I² = 73%).

CONCLUSIONS

There are few reports comparing endovascular vs open repair of TAAAs. Short-term outcomes may be improved in patients undergoing endovascular treatment of TAAA on the basis of a limited number of studies with high risk of bias. These findings highlight the need for larger comparative studies with standardization of reporting.

State-of the-art review on the renal and visceral protection during open thoracoabdominal aortic aneurysm repair

During open thoracoabdominal aortic aneurysm repair (OTAAAR), there is an inevitable organ ischemic period that occurs when the abdominal arteries are being reattached to the aortic graft. Despite various protective techniques, the incidence of renal and visceral complications remains substantial. This state-of-the-art review gives an overview of the current and most evidence-based organ protection methods during OTAAAR, based on the most recent publications and personal experience. An electronic search was performed in four medical databases, using the following MeSH terms: thoracoabdominal aneurysm, TAAAR, visceral protection, renal protection, kidney, perfusion, and intestines. Every publication type was considered. The literature search was ended on August 31st, 2017. The left heart bypass (LHB) is currently the most frequent adjunct to provide distal aortic perfusion (DAP) during aortic clamping. Together with systemic hypothermia, it forms the cornerstone in organ protection during aortic clamping. Further renal protection can be obtained by selective renal perfusion (SRP) with cold blood or cold crystalloid solution, the latter enriched with mannitol. The perfusion should be administered in a volume- and pressure-controlled way and, if possible, by use of a pulsatile pump. Selective visceral perfusion (SVP) is not routinely used, as it does not provide adequate blood flow for visceral protection. The best way to protect the intestines is by minimizing the ischemic time. The preservation of renal and visceral function after OTAAAR can only be obtained with specific strategies before, during, and after the operation. This involves a series of measures, including selective digestive decontamination (SDD), avoidance of nephrotoxic drugs, minimizing the renal and intestinal ischemic time, systemic cooling, avoidance of hemodynamic instability, and regional protective perfusion of the kidneys. Future innovations in catheters, cardiac bypass flow types, mechanical components, hybrid vascular grafts, and pharmaceutical protection measures will hopefully further reduce organ complications.

Early Outcomes of the t-Branch Off-the-Shelf Multibranched Stent-Graft in Urgent Thoracoabdominal Aortic Aneurysm Repair

Purpose: To assess the short-term outcomes of the multibranched off-the-shelf t-Branch stent-graft for urgent thoracoabdominal aortic aneurysm (TAAA) repair and to evaluate the impact on outcomes of the learning curve and adherence to the instruction for use (IFU). Methods: Between 2014 and 2017, 42 patients (mean age 73.3±7 years; 26 men) underwent urgent TAAA treatment using the t-Branch stent-graft [18 in the early (2014–2015) period and 24 in the late (2016–2017) period]. Nearly half the patients were symptomatic (n=18) and 12 had contained rupture. Aneurysm diameter >80 mm was present in 12 (mean diameter 77.7±13.2 mm). Nineteen patients did not meet the IFU for the t-Branch due to target vessel anatomy. The primary endpoints were spinal cord ischemia (SCI), renal function impairment, and 30-day mortality. Target vessel patency and endoleak incidence were assessed at 30 days. Multivariate analyses examined associations between perioperative variables and outcomes; the results are presented as the odds ratio (OR) and 95% confidence interval (CI). Results: The technical success rate was 93% (39/42). Successful catheterization was achieved in 150/155 target vessels (97%). The postoperative SCI rate was 21% (5 paraplegia/4 transient paraparesis) and was correlated with age (OR 1.26, 95% CI 1.01 to 1.56, p=0.04). The renal function impairment rate was 23% (10/42; 2 temporary, 2 permanent dialysis) and was correlated with early experience (OR 7.74, 95% CI 1.3 to 43.9, p=0.019). The 30-day mortality was 14% (no intraoperative deaths); no factor was associated with mortality. During the first month, the incidences of type I, II, and III endoleaks were 0%, 43%, and 0%, respectively; branch patency was 99% (150/151). Procedure time decreased in the later experience (479±333 vs 407±25 minutes, p=0.09), though it was increased in cases outside the IFU (497±135 vs 389±118 minutes, p=0.009), along with fluoroscopy time (121±48 vs 92±33 minutes, p=0.036). Conclusion: Endovascular repair of urgent TAAA using the t-Branch is a feasible treatment option with acceptable 30-day mortality and morbidity in terms of SCI and renal function impairment. Adherence to the IFU prolonged procedure time but had no effect on outcomes. Increased experience of such cases over time may improve outcomes.

One-Year Follow-Up After Hybrid Thoracoabdominal Aortic Repair

Background:

Compared to open thoracoabdominal aortic aneurysm (TAAA) repair, hybrid repair is thought to be less invasive with better perioperative outcomes. Due to the extent of the operation and long recovery period, studying perioperative results may not be sufficient for evaluation of the true treatment effect. The aim of this study is to evaluate 1-year mortality and morbidity in patients with TAAA undergoing hybrid repair.

Methods:

In a retrospective cohort study, all medical records of patients undergoing hybrid repair for TAAA at the Erasmus University Medical Center between January 2007 and January 2015 were studied. Primary outcome measures were 30-day and 1-year mortality. Secondary outcome measures included major in-hospital postoperative complications.

Results:

A total of 15 patients were included. All-cause mortality was 33% (5 of the 15) at 30 days and 60% (9 of the 15) at 1 year. Aneurysm-related mortality was 33% (5 of the 15) and 53% (8 of the 15) at 30-day and 1-year follow-up, respectively, with colon ischemia being the most common cause of death. Major complication rate was high: myocardial infarction in 2 (13%) cases, acute kidney failure in 5 (33%) cases, bowel ischemia in 3 (20%) cases, and spinal cord ischemia in 1 (7%) case.

Conclusion:

The presumed less invasive nature of hybrid TAAA repair does not seem to result in lower complication rates. The high mortality rate at 30 days continues to rise dramatically thereafter, suggesting that 1-year mortality is a more useful clinical parameter to use in preoperative decision-making for this kind of repair.

Short- and Long-term Results of Hybrid Arch and Proximal Descending Thoracic Aortic Repair

Purpose: To evaluate the short- and long-term outcomes of hybrid repair of the arch and proximal descending aorta in a single tertiary center for aortic disease. Methods: A retrospective analysis was performed of 55 patients (median age 67 years; 36 men) who underwent hybrid repair of thoracic aortic pathology with involvement of the arch between January 2005 and May 2015 at a single tertiary center. The pathologies included 40 (73%) with aneurysmal disease, 10 (18%) acute type B aortic dissections, 2 with acute aortic syndrome, an acute type A dissection, and left and aberrant right subclavian artery aneurysms. Seven (13%) procedures were performed as an emergency. Demographics and procedure characteristics were collected for analysis of survival and reinterventions. Results: Complete aortic debranching was performed in 14 (25%) to facilitate endograft placement in zone 0; debranching was partial in 20 (36%) patients for zone 1 deployments and 21 (38%) for zone 2. Primary technical success was achieved in 51 (93%) cases. One patient died in-hospital from aneurysm rupture following aortic debranching prior to stent-graft repair. In another, the stent-graft procedure proved infeasible and was abandoned. The other 2 technical failures were due to type Ia endoleaks. Five (9%) patients died in-hospital (4 of 48 elective and 1 of 7 emergency cases); 2 of these patients died within 30 days (4%). Eight (14%) patients had a stroke, 6 of 48 elective and 2 of the 7 emergency patients. Spinal cord ischemia was reported in 3 (6%) patients. Mean follow-up was 74.6 months. Overall cumulative survival was 70% at 1 year, 68% at 2 years, and 57% at 5 years. Reintervention to the proximal landing zone for type Ia endoleak was required in 6% of cases. The overall rate of aortic reintervention was 18% at 1 year, 21% at 2 years, and 36% at 5 years. Overall extra-anatomic graft patency was 99%. Conclusion: Hybrid repair of the aortic arch and proximal descending thoracic aorta is technically feasible, with acceptable short-term mortality. There is a low rate of proximal landing zone reintervention when hybrid techniques are used to create an adequate proximal landing zone. Extra-anatomic bypass grafts have good long-term patency. Ongoing disease progression means that further distal aortic interventions are often necessary in patients with extensive disease.

Multibranched Stent-Grafts for the Treatment of Thoracoabdominal Aortic Aneurysms

Purpose: To evaluate the available literature on endovascular repair of thoracoabdominal (TAAA) and pararenal aortic aneurysms (PRAA) using multibranched stent-grafts. Methods: MEDLINE, EMBASE, and Cochrane databases were searched between January 2001 and June 2015 to identify articles related to the use of multibranched stent-grafts for the treatment of TAAA and PRAA. Articles with <4 cases and those on juxtarenal aortic aneurysms were excluded. Meta-analyses were conducted to evaluate 30-day mortality, all-cause mortality, spinal cord ischemia, renal insufficiency, endoleak, target vessel patency, and reintervention. Of 370 articles screened, only 4 articles encompassing 185 patients (mean age 71.1 years; 137 men) were aligned with the inclusion criteria. There were 23 PRAAs; the mean aneurysm diameter was 64.5 mm. The Crawford TAAA classification was 10 type I, 47 type II, 37 type III, 58 type IV, and 9 type V; there was 1 Stanford type B dissection in association with a large TAAA. Results of the meta-analyses are reported as proportions and 95% confidence interval (CI). Results: Pooled analysis indicated a technical success rate of 98.9%. As study heterogeneity was significant, random effects models were used for meta-analysis. The rate for 30-day mortality was 9% (95% CI 3% to 19%), for all-cause mortality 27% (95% CI 17% to 38%), endoleaks 10% (95% CI 1% to 25%), target vessel patency 98% (95% CI 95% to 99%), SCI 17% (95% CI 1% to 26%), irreversible SCI 6% (95% CI 3% to 10%), renal insufficiency 15% (95% CI 0.8% to 41%), and reinterventions 21% (95% CI 4% to 47%). Conclusion: Use of multibranched stent-grafts in the treatment of TAAAs and PRAAs appears to be feasible and safe based on satisfactory early outcomes in the limited literature available to date. Long-term surveillance and further studies are essential to determine the durability of this technique.

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.

Outcomes of Thoracic Endovascular Aortic Repair and Subclavian Revascularization Techniques

BACKGROUND

Practice guidelines for management of the left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR) are based on low-quality evidence, and there is limited literature that addresses optimal revascularization techniques. The purpose of this study was to compare outcomes of LSA coverage during TEVAR and revascularization techniques.

STUDY DESIGN

We performed a single-center retrospective cohort study from 2001 to 2013. Patients were categorized by LSA revascularization and by revascularization technique, carotid-subclavian bypass (CSB), or subclavian-carotid transposition (SCT). Thirty-day and mid-term stroke, spinal cord ischemia, vocal cord paralysis, upper extremity ischemia, primary patency of revascularization, and mortality were compared.

RESULTS

Eighty patients underwent TEVAR with LSA coverage, 25% (n = 20) were unrevascularized and the remaining patients underwent CSB (n = 22 [27.5%]) or SCT (n = 38 [47.5%]). Mean follow-up time was 24.9 months. Comparisons between unrevascularized and revascularized patients were significant for a higher rate of 30-day stroke (25% vs 2%; p = 0.003) and upper extremity ischemia (15% vs 0%; p = 0.014). However, there was no difference in 30-day or mid-term rates of spinal cord ischemia, vocal cord paralysis, or mortality. There were no statistically significant differences in 30-day or midterm outcomes for CSB vs SCT. Primary patency of revascularizations was 100%. Survival analysis comparing unrevascularized vs revascularized LSA was statistically significant for freedom from stroke and upper extremity ischemia (p = 0.02 and p = 0.003, respectively). After adjustment for advanced age, urgency, and coronary artery disease, LSA revascularization was associated with lower rates of perioperative adverse events (odds ratio = 0.23; p = 0.034).

CONCLUSIONS

During TEVAR, LSA coverage without revascularization is associated with an increased risk of stroke and upper extremity ischemia. When LSA coverage is required during TEVAR, CSB and SCT are equally acceptable options.

Surgical management of thoracoabdominal aneurysms

Thoracoabdominal aneurysm of the aorta (TAAA) is a morbid condition, the treatment of which can be associated with high mortality and complication rates, as well as prolonged length of hospital stay. Currently, three approaches to treatment of TAAAs exist: open, endovascular and hybrid repair. Over the past three decades, a significant decrease in postoperative mortality and paraplegia rates has been achieved due to effective application of such treatment adjuncts as left heart bypass, cerebrospinal fluid drainage, application of hypothermia and neuromonitoring, thereby making surgical treatment of TAAAs increasingly safer for the patient. In this report, we review indications and current approaches to surgical management of TAAAs, as well as the factors that influence the efficacy of this type of treatment.

Role of induced hypothermia in thoracoabdominal aortic aneurysm surgery

For more than 50 years, hypothermia has been used in aortic surgery as a tool for neuroprotection. Hypothermia has been introduced into thoracoabdominal aortic aneurysm (TAAA) surgery by many cardiovascular centers to protect the body's organs, including the spinal cord. Numerous publications have shown that hypothermia can prevent immediate and delayed motor dysfunction after aortic cross-clamping. Here, we reviewed the historical application of hypothermia in aortic surgery, role of hypothermia in preclinical studies, cellular and molecular mechanisms by which hypothermia confers neuroprotection, and the role of systemic and regional hypothermia in clinical protocols to reduce and/or eliminate the devastating consequences of ischemic spinal cord injury after TAAA repair.

Descending thoracic aortic surgery: update on mortality, morbidity, risk assessment and management

PURPOSE OF REVIEW

The purpose of this review is to summarize the literature on thoracic aortic surgery, as well as key management guidelines in the perioperative period. This is particularly timely, as endovascular techniques continue to evolve and become more available.

RECENT FINDINGS

Endovascular treatment of thoracic aortic disease is expanding in applications and case complexity.

SUMMARY

With the expanded use of endovascular techniques to treat aortic disease, midterm and long-term outcome studies and comparisons to open surgical approach are now being published with increasing frequency. This review analyzes the available literature on preventing adverse outcomes after descending thoracic aortic surgery, with specific attention to mortality, morbidity, risk assessment and management in the perioperative setting.