Fenestrated-branched endovascular repair for distal thoraco-abdominal aortic pathology after total aortic arch replacement with frozen elephant trunk

OBJECTIVE

To report the outcomes of fenestrated-branched endovascular repair (FBEVAR) for thoracoabdominal aortic pathology after total aortic arch replacement with frozen elephant trunk (TAR+FET).

METHODS

Interrogation of prospectively-maintained databases from four high volume aortic centres identified consecutive patients treated with distal FBEVAR after prior TAR+FET between August 2013 and September 2020. Primary endpoint was 30-day/in-hospital mortality. Secondary end points were technical success, early clinical success, mid-term survival and freedom from re-intervention. Data are presented as median (IQR).

RESULTS

39 patients [21 men; median age, 73 years (67-75)] with degenerative (n=22) and post-dissection TAAAs (n=17) [median diameter 71 mm (61-78)] were identified. Distal FBEVAR was intended in 27 patients [median interval 9.8 months (6.2-16.6)], anticipated in seven and unexpected in five. 31 patients had a two (n=24) or three (n=7) stage distal FBEVAR. Reno-visceral target vessel preservation was 99.3% (145 of 146). Early primary and secondary technical success was 92% and 97%, respectively. 30-day mortality was 2.6% [n=1; respiratory failure and spinal cord ischaemia (SCI)]. Six survivors also developed SCI which was associated with complete (n=4), or partial recovery (n=2) at hospital discharge. No patients required renal replacement therapy or suffered a stroke. Early clinical success was 95%. Median follow-up was 30.5 months (23.7-49.7). Eleven patients required 16 late re-interventions. Estimated 3-year survival and freedom from re-intervention were 84±6% and 63±10%, respectively.

CONCLUSIONS

Distal FBEVAR after prior TAR+FET is associated with high technical success and low early mortality. The risk of SCI is significant although the majority of patients demonstrate full or partial recovery before hospital discharge. Mid-term patient survival is favourable but there remains a high requirement for late re-intervention. FBEVAR represents an acceptable alternative to distal open TAAA repair.

Remote preconditioning and major clinical complications following adult cardiovascular surgery: systematic review and meta-analysis

BACKGROUND

A number of 'proof-of-concept' trials suggest that remote ischaemic preconditioning (RIPC) reduces surrogate markers of end-organ injury in patients undergoing major cardiovascular surgery. To date, few studies have involved hard clinical outcomes as primary end-points.

METHODS

Randomised clinical trials of RIPC in major adult cardiovascular surgery were identified by a systematic review of electronic abstract databases, conference proceedings and article reference lists. Clinical end-points were extracted from trial reports. In addition, trial principal investigators provided unpublished clinical outcome data.

RESULTS

In total, 23 trials of RIPC in 2200 patients undergoing major adult cardiovascular surgery were identified. RIPC did not have a significant effect on clinical end-points (death, peri-operative myocardial infarction (MI), renal failure, stroke, mesenteric ischaemia, hospital or critical care length of stay).

CONCLUSION

Pooled data from pilot trials cannot confirm that RIPC has any significant effect on clinically relevant end-points. Heterogeneity in study inclusion and exclusion criteria and in the type of preconditioning stimulus limits the potential for extrapolation at present. An effort must be made to clarify the optimal preconditioning stimulus. Following this, large-scale trials in a range of patient populations are required to ascertain the role of this simple, cost-effective intervention in routine practice.

The effect of perhexiline on myocardial protection during coronary artery surgery: a two-centre, randomized, double-blind, placebo-controlled trial

OBJECTIVES

Perhexiline is thought to modulate metabolism by inhibiting mitochondrial carnitine palmitoyltransferase-1, reducing fatty acid uptake and increasing carbohydrate utilization. This study assessed whether preoperative perhexiline improves markers of myocardial protection in patients undergoing coronary artery bypass graft surgery and analysed its effect on the myocardial metabolome.

METHODS

In a prospective, randomized, double-blind, placebo-controlled trial, patients at two centres were randomized to receive either oral perhexiline or placebo for at least 5 days prior to surgery. The primary outcome was a low cardiac output episode in the first 6 h. All pre-specified analyses were conducted according to the intention-to-treat principle with a statistical power of 90% to detect a relative risk of 0.5 and a conventional one-sided α-value of 0.025. A subset of pre-ischaemic left ventricular biopsies was analysed using mass spectrometry-based metabolomics.

RESULTS

Over a 3-year period, 286 patients were randomized, received the intervention and were included in the analysis. The incidence rate of a low cardiac output episode in the perhexiline arm was 36.7% (51/139) vs 34.7% (51/147) in the control arm [odds ratio (OR) 0.92, 95% confidence interval (CI) 0.56–1.50, P = 0.74]. Perhexiline was associated with a reduction in the cardiac index at 6 h [difference in means 0.19, 95% CI 0.07–0.31, P = 0.001] and an increase in inotropic support in the first 12 h (OR 0.55, 95% CI 0.34–0.89, P = 0.015). There were no significant differences in myocardial injury with troponin-T or electrocardiogram, reoperation, renal dysfunction or length of stay. No difference in the preischaemic left ventricular metabolism was identified between groups on metabolomics analysis.

CONCLUSIONS

Preoperative perhexiline does not improve myocardial protection in patients undergoing coronary surgery and in fact reduced perioperative cardiac output, increasing the need for inotropic support. Perhexiline has no significant effect on the mass spectrometry-visible polar myocardial metabolome in vivo in humans, supporting the suggestion that it acts via a pathway that is independent of myocardial carnitine palmitoyltransferase inhibition and may explain the lack of clinical benefit observed following surgery.

ClinicalTrials.Gov ID

NCT00845364.

Current results of endovascular repair of thoraco-abdominal aneurysms†

OBJECTIVES

Fenestrated and branch endografts represent a totally endovascular solution for high-risk patients with atherosclerotic thoraco-abdominal aortic aneurysms (TAAAs). This study reports the early outcome of endovascular TAAA repair.

METHODS

Interrogation of a prospective database of consecutive patients who underwent endovascular repair (EVAR) for TAAA between June 2007 and October 2012.

RESULTS

Sixty-two high-risk patients (55 men; median age 72, range 54-84 years) underwent fenestrated (n = 39) or branch (n = 23) EVAR for non-ruptured TAAA [extent I-III (n = 26) and IV (n = 36)]. Twenty patients had undergone 22 previous aortic procedures. A total of 221 target vessels (coeliac 50, superior mesenteric 61, renal 106, left subclavian 1 and hypogastric 3) were preserved with scallops (n = 17), fenestrations (n = 140) or branches (n = 62) and 201 of these vessels were stent-grafted (coeliac 34, superior mesenteric 58, renal 105, left subclavian 1 and hypogastric 3). The 30-day mortality was 1.6% (n = 1) and one further patient died on postoperative day 62 from respiratory complications. Spinal cord injury (SCI) developed in 5 (8%) patients (3 women and 2 men). Two patients required temporary renal replacement therapy and a further two commenced planned postoperative dialysis.

CONCLUSIONS

In high-risk patients with TAAA, fenestrated and branch EVAR is associated with low early mortality and requirement for renal support, but the risk of SCI is not insignificant despite the use of cerebrospinal fluid drainage and blood pressure manipulation. Our current practice is to stage the repair of extent I-III aneurysms and this has significantly reduced the incidence of SCI.

Glucose-insulin-potassium reduces the incidence of low cardiac output episodes after aortic valve replacement for aortic stenosis in patients with left ventricular hypertrophy: results from the Hypertrophy, Insulin, Glucose, and Electrolytes (HINGE) trial

BACKGROUND

Patients undergoing aortic valve replacement for critical aortic stenosis often have significant left ventricular hypertrophy. Left ventricular hypertrophy has been identified as an independent predictor of poor outcome after aortic valve replacement as a result of a combination of maladaptive myocardial changes and inadequate myocardial protection at the time of surgery. Glucose-insulin-potassium (GIK) is a potentially useful adjunct to myocardial protection. This study was designed to evaluate the effects of GIK infusion in patients undergoing aortic valve replacement surgery.

METHODS AND RESULTS

Patients undergoing aortic valve replacement for aortic stenosis with evidence of left ventricular hypertrophy were randomly assigned to GIK or placebo. The trial was double-blind and conducted at a single center. The primary outcome was the incidence of low cardiac output syndrome. Left ventricular biopsies were analyzed to assess changes in 5' adenosine monophosphate-activated protein kinase (AMPK), Akt phosphorylation, and protein O-linked β-N-acetylglucosamination (O-GlcNAcylation). Over a 4-year period, 217 patients were randomized (107 control, 110 GIK). GIK treatment was associated with a significant reduction in the incidence of low cardiac output state (odds ratio, 0.22; 95% confidence interval, 0.10 to 0.47; P=0.0001) and a significant reduction in inotrope use 6 to 12 hours postoperatively (odds ratio, 0.30; 95% confidence interval, 0.15 to 0.60; P=0.0007). These changes were associated with a substantial increase in AMPK and Akt phosphorylation and a significant increase in the O-GlcNAcylation of selected protein bands.

CONCLUSIONS

Perioperative treatment with GIK was associated with a significant reduction in the incidence of low cardiac output state and the need for inotropic support. This benefit was associated with increased signaling protein phosphorylation and O-GlcNAcylation. Multicenter studies and late follow-up will determine whether routine use of GIK improves patient prognosis.

Remote ischemic preconditioning in human coronary artery bypass surgery: from promise to disappointment?

BACKGROUND

We assessed whether remote ischemic preconditioning (RIPC) improves myocardial, renal, and lung protection after on-pump coronary surgery.

METHODS AND RESULTS

This was a single-center, prospective, randomized (1:1), placebo-controlled trial. Patients, investigators, anesthetists, surgeons, and critical care teams were blinded to group allocation. Subjects received RIPC (or placebo) stimuli (×3 upper limb (or dummy arm), 5-minute cycles of 200 mm Hg cuff inflation/deflation) before aortic clamping. Anesthesia, perfusion, cardioplegia, and surgical techniques were standardized. The primary end point was 48-hour area under the curve (AUC) troponin T (cTnT) release. Secondary end points were 6-hour and peak cTnT, ECG changes, cardiac index, inotrope and vasoconstrictor use, renal dysfunction, and lung injury. Hospital survival was 99.4%. Comparing placebo and RIPC, median (interquartile range) AUC 48-hour cTnT (ng/mL(-1)/48 h(-1)); 28 (19, 39) versus 30 (22, 38), 6-hour cTnT (ng/mL(-1)); 0.93(0.59, 1.35) versus 1.01(0.72, 1.43), peak cTnT (ng/mL(-1)); 1.02 (0.74, 1.44) versus 1.04 (0.78, 1.51), de novo left bundle-branch block (4% versus 0%) and Q waves (5.3% versus 5.5%), serial cardiac indices, intraaortic balloon pump usage (8.5% versus 7.5%), inotrope (39% versus 50%) and vasoconstrictor usage (66% versus 64%) were not different. Dialysis requirement (1.2% versus 3.8%), peak creatinine (median [interquartile range], 1.2 mg/dL(-1) (1.1, 1.4) versus 1.2 (1.0, 1.4)), and AUC urinary albumin-creatinine ratios 69 (40, 112) versus 58 (32, 85) were not different. Intubation times; median (interquartile range), 937 minutes(766, 1402) versus 895(675, 1180), 6-hour; 278 (210, 338) versus 270 (218, 323) and 12-hour pO(2):FiO(2) ratios 255 (195, 323) versus 263 (210, 308) were similar.

CONCLUSIONS

In contrast to prior smaller studies, RIPC did not reduce troponin release, improve hemodynamics, or enhance renal or lung protection. Clinical Trial Registration-URL: http://www.ukcrn.org.uk. Unique identifier: 4659.