Graft flow evaluation with intraoperative transit-time flow measurement in off-pump versus on-pump coronary artery bypass grafting.

Objective: We aimed to compare transit-time flow measurement (TTFM) parameters for on-pump (ONCAB) and off-pump (OPCAB) coronary artery bypass procedures. Methods: The database of the Registry for Quality AssESsmenT with Ultrasound Imaging and TTFM in Cardiac Bypass Surgery (REQUEST) study was retrospectively reviewed. Only single grafts were included (ie, no sequential or Y/T grafts). Primary end points were mean graft flow (MGF), pulsatility index (PI), diastolic fraction (DF), and backflow (BF). Unadjusted and propensity score-matching comparisons were performed. Results: Of 1016 patients in the REQUEST registry, 846 had at least 1 graft for which TTFM was performed. Of these, 512 patients (60.6%) underwent ONCAB and 334 (39.4%) OPCAB procedures. Mean arterial pressure (MAP) during measurements was higher in the OPCAB group. After propensity score-matching, 312 well balanced pairs were left. In these matched patients, MGF was higher for the ONCAB versus the OPCAB group (32 vs 28 mL/min, respectively, for all grafts [P < .001]; 30 vs 27 mL/min for arterial grafts [P = .002]; and 35 vs 31 mL/min for venous grafts [P = .006], respectively). PI was lower in the ONCAB group (2.1 vs 2.3, for all grafts; P < .001). Diastolic fraction was slightly lower in the ONCAB group (65% vs 67.5%; P < .001). The backflow was also lower in the ONCAB group (0.6 vs 1.3; P < .001) with trends similar to MGF and PI for venous and arterial grafts. There were 21 (3.3%) revisions in the OPCAB group and 14 (2.1%) in the ONCAB group (P = .198). Conclusions: ONCAB surgery was associated with higher MGF and lower PI values, especially in venous grafts. Different TTFM cutoff values for ONCAB versus OPCAB surgery might be considered.

Stentectomy for LAD "full metal jacket" with in-stent restenosis: How to do it.

We report our technique for the surgical revascularization of symptomatic severe in-stent restenosis of a "full metal jacket" (≥60 mm overlapping stents) of the left anterior descending coronary artery without suitable distal targets: on-pump cardioplegic-arrest stent removal (stentectomy) with endarterectomy and skeletonized left internal mammary artery onlay patch reconstruction. We also describe our follow-up protocol, including antiplatelet/anticoagulation and angiography. With proper patient selection, multidisciplinary collaboration, and surgical expertise, this advanced coronary procedure can be beneficial to a growing population of patients otherwise deemed to be untreatable.

Transit time flow measurement of coronary bypass grafts before and after protamine administration.

BACKGROUND: Intraoperative graft assessment with tools like Transit Time Flow Measurement (TTFM) is imperative for quality control in coronary surgery. We investigated the variation of TTFM parameters before and after protamine administration to identify new benchmark parameters for graft quality assessment. METHODS: The database of the REQUEST ("REgistry for QUality AssESsmenT with Ultrasound Imaging and TTFM in Cardiac Bypass Surgery") study was retrospectively reviewed. A per graft analysis was performed. Only single grafts (i.e., no sequential nor composite grafts) where both pre- and post-protamine TTFM values were recorded with an acoustical coupling index > 30% were included. Grafts with incomplete data and mixed grafts (arterio-venous) were excluded. A second analysis was performed including single grafts only in the same MAP range pre- and post- protamine administration. RESULTS: After adjusting for MAP, we found a small increase in MGF (29 mL/min to 30 mL/min, p = 0.009) and decrease in PI (2.3 to 2.2, p <  0.001) were observed after the administration of protamine. These changes were especially notable for venous conduits and for CABG procedures performed on-pump. CONCLUSION: The small changes in TTFM parameters observed before and after protamine administration seem to be clinically irrelevant, despite being statistically significant in aggregate. Our data do not support a need to perform TTFM measurements both before and after protamine administration. A single TTFM measurement taken either before or after protamine may suffice to achieve reliable data on each graft's performance. Depending on the specific clinical situation and intraoperative changes, more measurements may be informative. TRIAL REGISTRATION: Clinical Trials Number: NCT02385344 , registered February 17th, 2015.

Acute Type A Aortic Dissection During the COVID-19 Outbreak.

As of April 7, 2020, approximately 1,300,000 cases and 80,000 deaths related to coronavirus disease 2019 (COVID-19) have been reported in more than 180 countries/territories. Health care infrastructures and resources, particularly as it relates to the care of the most critically ill patients, are currently being strained globally. In this context, however, there has been little clinical guidance or information regarding life-threatening conditions requiring emergency operation that cannot be delayed. We present a case of acute type A aortic dissection in a patient with COVID-19 to highlight the clinical implications of a true emergent procedure during the COVID-19 outbreak.

Is previous cardiac surgery a risk factor for open repair of acute type A aortic dissection?

OBJECTIVE: The study objective was to determine the optimal treatment for patients with acute type A aortic dissection and previous cardiac surgery. METHODS: A total of 545 patients underwent open repair of an acute type A aortic dissection (July 1996 to January 2017), including patients with (n = 50) and without previous cardiac surgery (n = 495). Data were collected through the University of Michigan Cardiac Surgery Data Warehouse, medical record review, and the National Death Index database. RESULTS: Compared with patients without previous cardiac surgery, patients with previous cardiac surgery were older (62 vs 59 years, P = .24) and had significantly more coronary artery disease (48% vs 14%, P < .001), peripheral arterial disease (24% vs 11%, P = .01), connective tissue disorders (15% vs 4.5%, P = .004), and acute renal failure on presentation (28% vs 15%, P = .02); and significantly more concomitant mitral or tricuspid procedures, longer cardiopulmonary bypass time, and more intraoperative blood transfusions. There were no statistically significant differences in postoperative major complications between previous cardiac surgery and no previous cardiac surgery groups, including stroke, myocardial infarction, new-onset dialysis, and 30-day mortality (8.9% vs 6.3%, P = .55). Multivariable logistic model showed the significant risk factors for operative mortality were cardiogenic shock (odds ratio, 9.6; P < .0001) and male gender (odds ratio, 3.7; P = .006). The 5- and 10-year unadjusted survivals were significantly lower in the previous cardiac surgery group compared with the no previous cardiac surgery group (66% vs 80% and 42% vs 66%, respectively, P = .02). However, previous cardiac surgery itself was not a significant risk factor for operative mortality (odds ratio, 1.6; P = .36) or all-time mortality (hazard ratio, 1.3; P = .33). CONCLUSIONS: Acute type A aortic dissection in patients with previous cardiac surgery can be repaired with favorable operative mortality and long-term survival, and should be treated surgically.

Severe re-expansion pulmonary edema after conventional cardiac surgery: Identification and management.

Re-expansion Pulmonary Edema (REPE) is a recognized but rare complication of lung re-inflation after pathologic collapse or intentional deflation. The presentation of REPE may be highly variable, ranging from a clinically asymptomatic, incidental radiologic finding to acute respiratory failure accompanied by severe, life-threatening hypoxemia. With the current report, we present a patient with severe aortic insufficiency, severe mitral regurgitation, coronary artery disease, pulmonary hypertension, who underwent aortic valve replacement, mitral valvuloplasty, coronary artery bypass grafting, and developed at the immediate post- operative period severe respiratory failure due to REPE, requiring venous-venous Extracorporeal Membrane Oxygenation (VV-ECMO).

Managing patients with acute type A aortic dissection and mesenteric malperfusion syndrome: A 20-year experience.

OBJECTIVE: To assess outcomes of endovascular reperfusion followed by delayed open aortic repair for stable patients with acute type A aortic dissection and mesenteric malperfusion syndrome (mesMPS). METHODS: Among 602 patients with acute type A aortic dissection who presented to our center from 1996 to 2017, all 82 (14%) with mesMPS underwent upfront endovascular fenestration/stenting. Primary outcomes were in-hospital mortality and long-term survival. Patients with acute type A aortic dissection with no malperfusion syndrome of any organ (n = 419) served as controls. RESULTS: In-hospital mortality of all comers with mesMPS was 39%. After endovascular fenestration/stenting, 20 mesMPS patients (24%) died from organ failure and 11 patients (13%) died from aortic rupture before open aortic repair, 47 patients (58%) underwent aortic repair, and 4 patients (5%) survived without open repair. No patients died from aortic rupture during the second decade (2008-2017). The significant risk factors for death from organ failure after endovascular reperfusion were acute stroke (odds ratio, 23; 95% confidence interval, 4-144; P = .0008), gross bowel necrosis at laparotomy (odds ratio, 7; 95% confidence interval, 1.4-34; P = .016), and serum lactate ≥6 mmol/L (odds ratio, 13.5; 95% confidence interval, 2-97; P = .0097). There was no significant difference in operative mortality (2.1% vs 7.5%; P = .50) or long-term survival between patients with mesMPS who underwent open aortic repair after recovering from mesMPS and patients with no malperfusion syndrome. CONCLUSIONS: In patients with acute type A aortic dissection with mesMPS, endovascular fenestration/stenting, and delayed open aortic repair achieved favorable short- and long-term outcomes. Surgeons should consider correcting mesenteric malperfusion before undertaking open aortic repair in patients with mesMPS, especially those with acute stroke, gross bowel necrosis at laparotomy, or serum lactate ≥6 mmol/L.

Endovascular Fenestration/Stenting First Followed by Delayed Open Aortic Repair for Acute Type A Aortic Dissection With Malperfusion Syndrome.

BACKGROUND: Immediate open repair of acute type A aortic dissection is traditionally recommended to prevent death from aortic rupture. However, organ failure because of malperfusion syndrome (MPS) might be the most imminent life-threatening problem for a subset of patients. METHODS: From 1996 to 2017, among 597 patients with acute type A aortic dissection, 135 patients with MPS were treated with upfront endovascular reperfusion (fenestration/stenting) followed by delayed open repair (OR). We compared outcomes between the first and second decades and observed mortalities with those expected with an "upfront OR for every patient" approach, determined using prognostic models from the literature (Verona, Leipzig-Halifax, Stockholm, Penn, and GERAADA [German Registry for Acute Aortic Dissection Type A] models). RESULTS: Overall, in-hospital mortality improved between the 2 decades (21.0% versus 10.7%, P<0.001). In the second decade, for patients with MPS initially treated with fenestration/stenting, mortality from aortic rupture decreased from 16% to 4% ( P=0.05), the risk of dying from organ failure was 6.6 times higher than dying from aortic rupture (hazard ratio=6.63; 95% CI, 1.5-29; P=0.01), and 30-day mortality after OR for MPS patients was 3.7%. Compared to the expected mortalities with the upfront OR for every patient models, our observed 30-day and in-hospital mortalities (9% and 11%, respectively) of all patients with acute type A aortic dissection were significantly lower ( P≤0.03). CONCLUSIONS: Immediate OR is the strategy to prevent death from aortic rupture for the majority of patients with acute type A aortic dissection. However, relatively stable (no rupture, no tamponade) patients with MPS benefit from a staged approach: upfront endovascular reperfusion followed by aortic OR at resolution of organ failure.