Umer Darr

What is the appropriate size criterion for resection of thoracic aortic aneurysms

Although many articles have described techniques for resection of thoracic aortic aneurysms, limited information on the natural history of this disorder is available to aid in defining criteria for surgical intervention. Data on 230 patients with thoracic aortic aneurysms treated at Yale University School of Medicine from 1985 to 1996 were analyzed. This computerized database included 714 imaging studies (magnetic resonance imaging, computed tomography, echocardiography). Mean size of the thoracic aorta in these patients at initial presentation was 5.2 cm (range 3.5 to 10 cm). The mean growth rate was 0.12 cm/yr. Overall survivals at 1 and 5 years were 85% and 64%, respectively. Patients having aortic dissection had lower survival (83% 1 year; 46% 5 year) than the cohort without dissection (89% 1 year; 71% 5 year). One hundred thirty-six patients underwent surgery for their thoracic aortic aneurysms. For elective operations, the mortality was 9.0%; for emergency operations, 21.7%. Median size at time of rupture or dissection was 6.0 cm for ascending aneurysms and 7.2 cm for descending aneurysms. The incidence of dissection or rupture increased with aneurysm size. Multivariable regression analysis to isolate risk factors for acute dissection or rupture revealed that size larger than 6.0 cm increased the probability by 32.1 percentage points for ascending aneurysms (p = 0.005). For descending aneurysms, this probability increased by 43.0 percentage points at a size greater than 7.0 cm (p = 0.006). If the median size at the time of dissection or rupture were used as the intervention criterion, half of the patients would suffer a devastating complication before the operation. Accordingly, a criterion lower than the median is appropriate. We recommend 5.5 cm as an acceptable size for elective resection of ascending aortic aneurysms, because resection can be performed with relatively low mortality. For aneurysms of the descending aorta, in which perioperative complications are greater and the median size at the time of complications is larger, we recommend intervention at 6.5 cm.

Cognitive and functional status predictors of delirium and delirium severity after coronary artery bypass graft surgery: an interim analysis of the Neuropsychiatric Outcomes After Heart Surgery study.

BACKGROUND Cognitive and functional impairment increase risk for post-coronary artery bypass graft (CABG) surgery delirium (PCD), but how much impairment is necessary to increase PCD risk remains unclear. METHODS The Neuropsychiatric Outcomes After Heart Surgery (NOAHS) study is a prospective, observational cohort study of participants undergoing elective CABG surgery. Pre-operative cognitive and functional status based on Clinical Dementia Rating (CDR) scale and neuropsychological battery are assessed. We defined mild cognitive impairment (MCI) based on either (1) CDR global score 0.5 (CDR-MCI) or (2) performance 1.5 SD below population means on any cognitive domain on neurocognitive battery (MCI-NC). Delirium was assessed daily post-operative day 2 through discharge using the confusion assessment method (CAM) and delirium index (DI). We investigate whether MCI - either definition - predicts delirium or delirium severity. RESULTS So far we have assessed 102 participants (mean age 65.1 ± 9; male: 75%) for PCD. Twenty six participants (25%) have MCI-CDR; 38 (62% of those completing neurocognitive testing) met MCI-NC criteria. Fourteen participants (14%) developed PCD. After adjusting for age, sex, comorbidity, and education, MCI-CDR, MMSE, and Lawton IADL score predicted PCD on logistic regression (OR: 5.6, 0.6, and 1.5, respectively); MCI-NC did not (OR [95% CI]: 11.8 [0.9, 151.4]). Using similarly adjusted linear regression, MCI-CDR, MCI-NC, CDR sum of boxes, MMSE, and Lawton IADL score predicted delirium severity (adjusted R(2): 0.26, 0.13, 0.21, 0.18, and 0.32, respectively). CONCLUSIONS MCI predicts post-operative delirium and delirium severity, but MCI definition alters these relationships. Cognitive and functional impairment independently predict post-operative delirium and delirium severity.

Enterochromaffin‐like Cell Pathobiology of Mastomys

Until recently, gastric neoplasia was regarded as predominantly adenocarcinoma in origin. Stromal tumors of unknown malignant potential were considered of interest, but rare. More recently, attention has been focused upon the development of neuroendocrine neoplasia of the gastric fundus.’ These lesions are predominantly of enterochromaffin cell, or enterochromaffin-like cell origin. Of particular interest are reports that enterochromaffin-like (ECLHerived tumor cells may be present in 40% of gastric carcinomas of the diffuse type.2 In general, it appears that there is a significant relationship between either low acid states or hypergastrinemia, and the genesis of fundic ECLomas.% The characterization of the cells involved in the neoplasm and the pathophysiology of the lesion itself are not yet clearly delineated. In order to investigate the biology of the enterochromaffin-like cell type, and the genesis of its neoplasia, we have studied the rodent species mastomys. This animal derives from the sub-Saharan desert areas and was initially used in the epidemiologic study of plague vectors. During these studies, it became apparent that a large percentage of the animals died from gastric neoplasia, which was later characterized as gastric carcinoid.’~~ More detailed studies revealed the tumor to be of ECL cell rig in.^ The lesion produces histamine and can be generated in association with hypergastrinemia related to a sustained low acid state. In previous studies, we have demonstrated that any pharmacotherapeutic agent capable of producing prolonged and sustained acid inhibition generates a sequence of hyperplasia, dysplasia, and neoplasia of the fundic ECL cells of mastornys.’&l2 In untreated animals of our breeding strain, 15-30% spontaneously develop gastric carcinoids within two years. Under circumstances of sustained acid inhibitory therapy, up to 80% of animals will develop gastric carcinoids within four months.’OIn order to investigate the regulatory mechanisms responsible for the development of this neoplastic phenomenon, we evaluated a number of agents with respect to their ability to induce ECL cell neoplasia. We used the irreversible histamine-H, receptor antagonist (H,RA), loxtidine, to generate a sustained low acid state. Because it was apparent that there was a predominant female incidence in the development of the neoplasia, we further

Multimodality serial follow-up of thoracic aortic aneurysms

We identified 520 diagnostic imaging tests (MRI, CT, ECHO) performed in 205 patients (79 female 126 male) (age 20–94, mean 63.9) being followed at Yale-New Haven hospital for progression in size of their thoracic aortas. Estimated growth rates did not differ significantly across imaging modalities.The average maximal size of the thoracic aorta was 5.3 cm (range 3.5–10.0). Mean maximal size was 5.3 cm in the 326 imaging studies without dissections. Mean size at time of dissection (N=22) was 6.2 cm, and a time of rupture (N=7), 6.5 cm.Survival at 3 and 5 years was 66% and 45%, respectively. Subjects having aortic dissection had lower survival (58% 3 year; 15% 5 year) than the non-dissected cohort (70% 3 year; 60% 5 year).Mean estimated growth rate on 53 patients followed serially for aortic expansion was 0.1 cm/yr. Stepwise multivariate risk factor analysis indicated that large (>=6.0 cm) aneurysms grew significantly more rapidly (p<0.02), that aneurysms located in the ascending aorta or arch grew more slowly than aneurysms located in the descending thoracic or thoraco-abdominal aorta (p<0.04), and that aneurysms grew more rapidly among male patients than among females (p<0.02).We conclude that (1) the overall growth rate in thoracic aorta aneurysms is 0.1 cm/yr. (2) Large aneurysms grow more rapidly than smaller ones. (3) Aneurysms grow more slowly in the ascending thoracic aorta or arch than on other locations of the thoracic aorta. (4) Aneurysms appear to grow somewhat more rapidly among male patients than among females. (5) One-half of aortic dissections and ruptures occur at sizes <6.0 cm. (6) Long-term survival prospects are less for patients having dissected aortas. (7) 5.0–5.5 cm is an appropriate criterion for surgical intervention in the thoracic aorta to prevent rupture or dissection.

Prevention of Aortic Dissection Suggests a Diameter Shift to a Lower Aortic Size Threshold for Intervention

Background: Multiple studies have quantified the relationship between aortic size and risk of dissection. However, these studies estimated the risk of dissection without accounting for any increase in aortic size from the dissection process itself. Objectives: This study aims to compare aortic size before and after dissection and to evaluate the change in size consequent to the dissection itself. Methods: Fifty-five consecutive patients (29 type A; 26 type B) with aortic dissection and incidental imaging studies prior to dissection were identified and compared to a control group of aneurysm patients (n = 205). The average time between measurement at and prior to dissection was 1.7 ± 1.9 years (1.9 ± 2.0 years mean inter-image time in the control group). A multivariate regression model controlling for growth rate, age, and gender was created to estimate the effect of dissection itself on aortic size. Results: The mean aortic sizes at and prior to dissection were 54.2 ± 7.0 and 45.1 ± 5.7 mm for the ascending aorta, and 47.1 ± 13.8 and 39.5 ± 13.1 mm for the descending aorta, respectively. The multivariable analysis revealed a significant impact of the dissection itself (p < 0.001) and estimated an increase in size of 7.65 mm (ascending aorta) and 6.38 mm (descending aorta). Thus, a proportional estimate of 82.8% (ascending aorta) and 80.8% (descending aorta) of dissections are made at a size lower than the guideline-recommended threshold (55 mm). Conclusions: The aortic diameter increases substantially due to aortic dissection itself and, thus, aortas are being dissected at clinically meaningfully smaller sizes than natural history analyses have previously suggested. These findings have important implications regarding the size at which the risk of dissection is increased.

Elective surgery for ascending aortic aneurysm in the elderly: should there be an age cut-off?†

OBJECTIVES The objective of this study is to retrospectively analyse surgical outcomes in patients aged 75-79, and 80 and above. METHODS Between 2000 and 2015, 108 patients aged 75-79 (G 75 , mean age 76.9 ± 1.5years) and 72 patients aged 80 and above (G 80 , mean age 82.2 ± 2.1years) underwent elective aneurysm repair. Operative outcome and survival was compared with 727 contemporary younger counterparts aged <75 years (G Ctrl , mean age 56.6 ± 11.7years). RESULTS Postoperatively, patients with advanced age showed a higher incidence of prolonged ventilation (G 80 21.4%, G 75 8.4%, G Ctrl 2.9%; P < 0.001), low cardiac output syndrome (G 80 11.4%, G 75 1.9%, G Ctrl 2.2%; P = 0.001), multi organ failure (G 80 2.9%, G 75 0%, G Ctrl 0.1%; P = 0.022), haemofiltration (G 80 8.6%, G 75 0.9%, G Ctrl 0.6%; P < 0.001), and infection (G 80 10.0%, G 75 6.5%, G Ctrl 3.5%; P = 0.017). Operative mortality was significantly increased in the elderly (G 80 11.1%, G 75 3.7%, G Ctrl 1.4%; P < 0.001). Mid-term survival differed significantly between the surgical groups. Multivariate regression analysis precluded age as an independent predictor of operative mortality. CONCLUSIONS Elderly patients showed a higher operative risk compared to their younger counterparts. However, age per se is no suitable indicator of surgical risk and well-selected patients with large threatening aneurysms may benefit from intervention.

CORONARY ARTERY BYPASS FOR ADVANCED LEFT VENTRICULAR DYSFUNCTION

Although courageous forays into the application of coronary artery bypass grafting (CABG) to the patient with advanced left ventricular dysfunction were made since the early davs of open heart surgery, the opinion that the patient with advanced left ventricular dysfunction could not and should not be offered coronary artery bypass surgery prevailed well into the 1980’s. The reluctance centered around three concerns: (1) that the risk of operation would be prohibitive, (2) that little symptomatic or longevity benefit would accrue from CABG, and (3) that CABG would merely punctuate an inevitable course of inexorable deterioration. Cardiologists were therefore reluctant to refer such patients for coronary revascularization and surgeons were reluctant to accept such patients. In terms of scientific evaluation, most large multicenter trials of coronary artery bypass grafting purposely excluded patients with advanced left ventricular dysfunction. (Ejection fraction was >35/a in the Coronary Artery Surgery Study (CASS) and >50% for the European Coronary Surgery Study (ECSS)).1,2

Comparable perioperative outcomes and mid-term survival in prosthetic valve endocarditis and native valve endocarditis

OBJECTIVES Cardiac surgery for prosthetic valve endocarditis (PVE) represents one of the highest risk surgeries with in-hospital mortality of 20%. Given the complex nature of the operation, the operative outcome is likely strongly susceptible to the surgeons experience and centre case volume, as measurements often are not apparent in large observational studies. We sought to evaluate operative outcomes and mid-term survival of patients with PVE compared with those of native valve endocarditis (NVE) at a tertiary care hospital. METHODS We conducted a single-institutional retrospective review of 188 consecutive patients (146 NVE and 42 PVE) undergoing cardiac surgery for endocarditis between 2011 and 2016 at a tertiary care hospital in the USA. A logistic regression model was fit to evaluate patient characteristics and perioperative outcomes in PVE and NVE: operative mortality and composite events (death, stroke, prolonged intubation, renal failure and sepsis). The Kaplan-Meier analysis was used to estimate the mid-term survival. The Cox proportional hazard model was fit to assess the adjusted risk associated with mid-term survival. RESULTS Operative mortality was 4.1% for NVE and 0% for PVE (P = 0.34). Composite events occurred in 30.6% and 38.1% of NVE and PVE, respectively (P = 0.45). Multivariable logistic regression for composite events showed that PVE was not associated with increased risk of adverse events [odds ratio 1.4, 95% confidence interval (CI) 0.6-3.4; P = 0.49]. The Kaplan-Meier analysis demonstrated no statistically significant difference in survival (P = 0.99). Finally, the Cox proportional hazard analysis for mid-term mortality demonstrated that PVE was not associated with increased risk for hazard of death: hazard ratio 0.4, 95% CI 0.2-1.1; P = 0.085. CONCLUSIONS Surgery for PVE can yield a low mortality rate with mid-term survival comparable with those of NVE. The diagnosis of PVE alone should not deter surgeons from operating on this complex patient population, provided that surgical expertise and experienced multidisciplinary team equipped to handle complex clinical scenarios are available.

Use of four-factor prothrombin complex concentrate for the mitigation of rivaroxaban-induced bleeding in an emergent coronary artery bypass graft

We presented the first case of four‐factor prothrombin complex concentrate (4F‐PCC) for the alleviation of bleeding for emergent on‐pump coronary artery bypass graft (CABG) with the patient discharged by postoperative day (POD) 9 with no sequelae. Until direct antidotes are available, 4F‐PCC may play a role in the management of mitigating rivaroxaban‐induced bleeding in surgical procedure.