Effect of computed tomography before cardiac surgery on surgical strategy, mortality and stroke

Impact of preoperative computed tomography scan on neurological outcomes in coronary artery bypass grafting patients: A propensity-score analysis

INTRODUCTION

Neurological complications pose significant risks in coronary artery bypass grafting (CABG). This study explores the potential benefits of preoperative chest computed tomography (CT) in optimizing outcomes and reducing neurological events in high-risk CABG patients.

METHODS

From January 2017 to June 2023, a retrospective cohort study of CABG patients categorized groups based on preoperative chest CT use. Multivariate analysis evaluated the associations between CT imaging and patient characteristics, followed by propensity match analysis to balance preoperative features across groups.

RESULTS

The study included 1786 patients, with 435 having undergone preoperative CT and 1351 without. Propensity matching created two well-balanced groups of 413 patients each. At multivariate analysis, CT patients were elderly (71.1 ± 8.9 years; p = 0.03) with a higher incidence of pulmonary disease (19.5%; p < 0.01), peripheral arterial disease (29.2%; p < 0.01), and previous cerebrovascular disease (23.4%; p = 0.02). In the matched CT cohort, the perioperative cerebral stroke rate was 0.7% (vs. 1.9% in without preoperative CT [WCT] cohort; p = 0.223), and the 30-day mortality rate was 0.2% (vs. 1.7% in WCT cohort; p = 0.069). Patients who had a preoperative CT study presented a higher prevalence of porcelain aorta (6.3% vs. 1.5%; p = 0.0003) and required more often a no-touch aorta procedure (20.3% vs. 14.5%; p = 0.035).

CONCLUSIONS

Patients undergoing preoperative chest CT before CABG were typically older and had systemic atherosclerosis and pulmonary disease. Propensity-matched analysis indicated low mortality and perioperative cerebral stroke rates in these high-risk patients. These findings support the integration of chest CT into preoperative evaluations for high-risk patients to develop tailored strategies in coronary artery bypass surgery.

Left Ventricular Assist Device Implantation with Concomitant Replacement of the Ascending Aorta

Dilated cardiomyopathy (DCM) is one of the main causes for end-stage heart failure. Until the transplantation, left ventricular assist devices (LVAD) have become an established treatment. We report a case of a 66-year-old patient with ischemic and DCM and suspected aortic ulcer formation. LVAD was implanted in the same session with a supracoronary aortic replacement. Bilateral cannulation of the subclavian arteries omitted the need of circulatory arrest and proximal aortic cross-clamping. Pneumonia-associated decarboxylation failure prolonged the postoperative intensive care period. The patient was finally discharged home on the 115 th postoperative day.

Routine preoperative screening computed tomography of the thorax for cardiac surgery

Introduction

This study aimed to evaluate the role of screening computed tomography (CT) of the thorax in cardiac surgery by analysing the presence of CT aortic calcifications in association with changes in operative strategy and postoperative stroke, and the CT features of emphysema with development of pneumonia.

Methods

All patients who underwent cardiac surgery from January 2013 to October 2017 by a single surgeon were retrospectively studied. Patients who underwent screening CT thorax before cardiac surgery (CT group) were compared to those who did not (no CT group). Multivariate subgroup analyses were performed to determine significant association with postoperative outcomes.

Results

A total of 392 patients were included, of which 156 patients underwent preoperative screening CT thorax. Patients in the CT group were older (63.9 vs. 59.0 years, P = 0.001), had fewer recent myocardial infarctions preoperatively (41% vs. 56.4%, P = 0.003) and had better ejection fraction (>30%; P = 0.02). Operative strategy was changed in 4.3% of patients, and 4.9% of patients suffered stroke postoperatively. The presence of CT aortic calcifications was significantly associated with change in operative strategy (P = 0.016) but not with postoperative stroke (P = 0.33). Age was an independent risk factor for change in operative strategy among patients with CT thorax (P = 0.02). Multivariate age-adjusted analysis showed only palpable plaque to be significantly associated with change in operative strategy (P < 0.001). None of the patients with CT emphysema features developed pneumonia.

Conclusion

The results of this study do not support routine use of preoperative screening CT thorax. Contrasted CT may be advisable in older patients and for other operative planning purposes.

Multivessel Coronary Disease and Severe Atherosclerotic Aorta: Real-World Experience

Background and Objectives: Surgical revascularisation of patients with atherosclerosis of the ascending aorta remains a challenge. Different surgical strategies have been described in coronary surgical patients to offer alternative revascularisation strategies other than the conventional surgical revascularisation in patients unsuitable for it. The aim of this study is to compare the real-world outcomes between two groups of patients who underwent off-pump surgery (left internal mammary artery graft to the left anterior descending artery) or a hybrid with a percutaneous revascularisation procedure at a later stage. Materials and Methods: This is a single-centre retrospective observational study. Between the years 2010 and 2021, 91/6863 patients (1.33%) were diagnosed with severe atherosclerosis of the ascending aorta. All the patients were treated with off-pump revascularisation (91 patients), and the cardiologist would decide at a later stage whether the rest of the vessels would be treated with percutaneous revascularisation (25 patients). Results: There was no statistical difference in the various preoperative characteristics, except for coronary artery left main disease (30.30% vs. 64%; p = 0.0043). The two groups had no statistical differences in the perioperative characteristics and postoperative complications. The 1-, 5-, and 10-year mortality rates in the two groups were 6.1% vs. 0%, 59% vs. 80%, and 93.9% vs. 100%, respectively (off-pump vs. hybrid with percutaneous revascularisation procedure, p = 0.1958). Conclusions: Both strategies have high long-term comparable mortality. The off-pump surgery and the HCR procedure at a later stage may be solutions for these high-risk patients, but the target treatment should be complete HCR revascularisation during the index hospitalization.

The routine use of preoperative non-contrast chest computerized tomography and carotid arteries Doppler prior to cardiac surgery

Introduction

There is no consensus as to which patients should undergo Non-Contrast Chest Computerized Tomography (NCCCT) and carotid arteries Doppler (CD) prior to cardiac surgery. The objective of this study was to examine whether preoperative imaging modalities provide clinical benefits and a change in surgical strategy.

Methods

We routinely performed NCCCT and CD in all non-urgent cardiac surgery patients. Major NCCCT/CD findings related to cardiovascular findings (aortic calcification/atherosclerosis, carotid artery plaque/stenosis), or other incidental findings (lung kidney, thyroid, adrenal, gastrointestinal sites etc.) were documented. The results were divided into 3 categories: (A) findings requiring both changes in surgical strategy and post-operative evaluation/treatment; (B) findings requiring changes in surgical strategy, but not requiring a specific post-operative evaluation/treatment; (C) findings not requiring changes in surgical strategy but requiring post-operative evaluation/treatment.

Results

In this cohort, 93 (18.6%) out of 500 patients had significant cardiac and extra-cardiac findings on NCCCT and/or CD. Among the 93 patients with significant findings, 33.33% (31 patients, 6.2% of all patients) were in group A, 7.5% (7 patients, 1.4% of all patients) were in group B, and 59.14% (55 patients, 11% of all patients) were in group C. Change in surgical strategies included, for example, switching from planned on-pump Coronary Artery Bypass Graft surgery (CABG) to off-pump CABG and performing additional procedures to the originally planned heart surgery.

Conclusion

Routine preoperative NCCCT and CD evaluation in all non-urgent cardiac surgical patients is an effective measure for uncovering cardiac and extra-cardiac findings prior to surgery.

Use of computed tomography (CT) for preoperative planning in patients undergoing coronary artery bypass grafting (CABG)

Surgical planning for coronary artery bypass grafting (CABG) can be enhanced with the use of computed tomographic (CT) imaging to better understand the surgical field for optimal conduct of the case as well as risk assessment for outcomes. CABG via primary sternotomy, redo sternotomy, and minimally-invasive thoracotomy each pose unique surgical considerations and risks that can be better characterized with a preoperative CT scan. CT and CT angiographic (CTA) techniques with or without intravenous (IV) contrast can provide a noninvasive assessment of the vascular and bony structures and direct surgical planning techniques. Herein we discuss the role of CT/CTA imaging of the chest in preoperative planning of different strategies of CABG.

Clinical Use of Tailored Computed Tomography to Prevent Poststernotomy Dehiscence

BACKGROUND

 Morphological and tissue density analysis of the sternum can be performed in the preoperative computed tomography (CT). The purpose of this study was to analyze morphology and tissue density of sternum in CT and effect for comparison sternal instability.

METHODS

 Patients with sternal instability (n = 61) and sternal stability (n = 66) were enrolled in this study. All of the patients were studied using same thorax CT procedure. All the measurements were performed by one specific cardiovascular radiologist. The Hounsfield units (HUs) were measured in axial sections of the sternum trabecular bone.

RESULTS

 Sternal instability group mean HU was 75.36 ± 13.19 and sternal stability group HU was 90.24 ± 12.16 (p < 0.000). HU is the statically significant predictor of sternal instability.

CONCLUSION

 Our study showed a significant correlation between the mean HU value of sternum and sternal instability. We think that it is important to evaluate the existing thorax CT while performing preoperative risk analysis for sternal dehiscence.

Effect of routine preoperative screening for aortic calcifications using noncontrast computed tomography on stroke rate in cardiac surgery: the randomized controlled CRICKET study

Objectives

To evaluate if routine screening for aortic calcification using unenhanced CT lowers the risk of stroke and alters the surgical approach in patients undergoing general cardiac surgery compared with standard of care (SoC).

Methods

In this prospective, multicenter, randomized controlled trial, adult patients scheduled for cardiac surgery from September 2014 to October 2019 were randomized 1:1 into two groups: SoC alone, including chest radiography, vs. SoC plus preoperative noncontrast CT. The primary endpoint was in-hospital perioperative stroke. Secondary endpoints were preoperative change of the surgical approach, in-hospital mortality, and postoperative delirium. The trial was halted halfway for expected futility, as the conditional power analysis showed a chance < 1% of finding the hypothesized effect.

Results

A total of 862 patients were evaluated (SoC-group: 433 patients (66 ± 11 years; 74.1% male) vs. SoC + CT-group: 429 patients (66 ± 10 years; 69.9% male)). The perioperative stroke rate (SoC + CT: 2.1%, 9/429 vs. SoC: 1.2%, 5/433, p = 0.27) and rate of changed surgical approach (SoC + CT: 4.0% (17/429) vs. SoC: 2.8% (12/433, p = 0.35) did not differ between groups. In-hospital mortality and postoperative delirium were comparable between groups. In the SoC + CT group, aortic calcification was observed on CT in the ascending aorta in 28% (108/380) and in the aortic arch in 70% (265/379).

Conclusions

Preoperative noncontrast CT in cardiac surgery candidates did not influence the surgical approach nor the incidence of perioperative stroke compared with standard of care. Aortic calcification is a frequent finding on the CT scan in these patients but results in major surgical alterations to prevent stroke in only few patients.

Key Points

• Aortic calcification is a frequent finding on noncontrast computed tomography prior to cardiac surgery.

• Routine use of noncontrast computed tomography does not often lead to a change of the surgical approach, when compared to standard of care.

• No effect was observed on perioperative stroke after cardiac surgery when using routine noncontrast computed tomography screening on top of standard of care.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08360-4.

Absent right superior vena cava with persistent left superior vena cava in a patient with COVID-19

Vascular injury associated with cannulation during extracorporeal membrane oxygenation (ECMO) induction is a rare but life-threatening complication. The presence of abnormal vascular anatomy increases the risk of vascular injury and should be recognized before cannulation. We report the case of a patient with coronavirus disease (COVID-19) who was expected to undergo ECMO. By performing computed tomography (CT), we identified the absence of right superior vena cava (RSVC) with a persistent left superior vena cava (PLSVC) that could have caused serious complications associated with ECMO cannulation. PLSVC is observed in less than 0.5% of the general population; however, the combination of PLSVC and an absent RSVC in visceroatrial situs solitus is extremely rare. Attempting cannulation for Veno-venous (VV)-ECMO from the right (or left) internal jugular vein to the right atrium may cause serious complications. Cannulation may fail or lead to complications even in patients with inferior vena cava malformations. Although these vascular abnormalities are rare, it is possible to avoid iatrogenic vascular injury by identifying their presence in advance. Since anatomical variations in the vessels from the deep chest and abdominal cavity cannot be visualized using chest radiography and ultrasonography, we recommend CT, if possible, for patients with severe respiratory failure, including those with COVID-19, who may be considered for VV-ECMO induction.

Preoperative Computed Tomography in the Adult Cardiac Surgery Patient

Increasingly, computed tomography is requested for preoperative planning prior to cardiac surgery. Common pathologies, such as aortic and mitral annular calcification, can influence the choice of surgical technique or approach. In this article, we present a case-based review of primary and reoperative sternotomies that focuses on the clinical relevance of the common pathologies and findings in pre-operative computed tomography images, with respect to surgical decision-making and management.

Frequency of abnormal findings on routine chest radiography before cardiac surgery

OBJECTIVE

Preoperative chest radiograph screening is widely used before cardiac surgery. The objective of this study was to investigate the frequency of abnormal findings on a routine chest radiograph before cardiac surgery.

METHODS

In this retrospective cohort study, 1136 patients were included. Patients were scheduled for cardiac surgery and underwent a preoperative chest radiograph. The primary outcome was the frequency of abnormalities on the chest radiograph. Secondary outcome was the effect of those abnormalities on surgery.

RESULTS

One half of the patients (570/1136; 50%) had 1 or more abnormalities on the chest radiograph. Most frequent abnormalities were cardiomegaly, aortic elongation, signs of chronic obstructive pulmonary disease, vertebral fractures or height loss, possible pulmonary or mediastinal mass, pleural effusion, and atelectasis. In 2 patients (2/1136; 0.2%), the chest radiograph led to postponement of surgery, whereas in none of the patients the surgery was cancelled. In 1 patient (1/1136; 0.1%) the surgical approach was altered and in 15 patients (15/1136; 1.3%) further analysis was performed without having an impact on the planned surgical approach.

CONCLUSIONS

Although abnormalities are frequently found on preoperative chest radiographs before cardiac surgery, change in clinical management with regard to planned surgery or surgical approach occurs infrequently.

Does routine preoperative computed tomography imaging provide clinical utility in patients undergoing primary cardiac surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, in patients undergoing primary cardiac surgery, does routine preoperative computed tomography (CT) imaging provide clinical benefit as measured by either a decrease in complications or a change in surgical approach. Altogether, 125 papers were found using the reported search, of which 5 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. All 5 studies reviewed reported change in operative strategy as a result of preoperative imaging, with the most common change being an alternative cannulation site. Two comparative studies reported decreased mortality and decreased perioperative stroke in patients who undergo preoperative CT, when compared to patients who do not. However, the results from these 2 studies are difficult to interpret as they used different imaging modalities and different patient populations. One study selected high-risk patients for preoperative CT, rather than routine use, but the findings were similar. We conclude that preoperative CT, whether non-contrast CT or CT angiography, can help optimize operative strategy and decrease postoperative stroke rate and mortality after primary cardiac surgery.

Tin-filtered low-dose chest CT to quantify macroscopic calcification burden of the thoracic aorta

OBJECTIVES

To compare a low-dose, tin-filtered, nonenhanced, high-pitch Sn100 kVp CT protocol (Sn100) with a standard protocol (STP) for the detection of calcifications in the ascending aorta in patients scheduled for cardiac surgery.

METHODS

Institutional Review Board approval for this retrospective study was waived and the study was HIPAA-compliant. The study included 192 patients (128 men; age 68.8 ± 9.9 years), of whom 87 received the STP and 105 the Sn100 protocol. Size-specific dose estimates (SSDE) and radiation doses were obtained using dose monitoring software. Two blinded readers evaluated image quality on a scale from 1 (low) to 5 (high) and the extent of calcifications of the ascending aorta on a scale from 0 (none) to 10 (high), subdivided into 12 anatomic segments.

RESULTS

The Sn100 protocol achieved a mean SSDE of only 0.5 ± 0.1 mGy and 0.20 ± 0.04 mSv compared with the mean SSDE of 5.4 ± 2.2 mGy achieved with the STP protocol (p < 0.0001). Calcification burden was associated with age (p < 0.0001), but was independent of protocol with mean calcification scores of 0.48 ± 1.23 (STP) and 0.55 ± 1.25 (Sn100, p = 0.18). Reader agreement was very good (STP κ = 0.87 ± 0.02, Sn100 κ = 0.88 ± 0.01). The STP protocol provided a higher subjective image quality than the Sn100 protocol: STP median 4, interquartile range 4-5, vs. SN100 3, 3-4; p < 0.0001) and a slightly better depiction of calcification (STP 5, 4-5, vs. Sn100 4, 4-5; p < 0.0001).

CONCLUSIONS

The optimized Sn100 protocol achieved a mean SSDE of only 0.5 ± 0.1 mGy while the depiction of calcifications remained good, and there was no systematic difference in calcification burden between the two protocols.

KEY POINTS

• Tin-filtered, low-dose CT can be used to assess aortic calcifications before cardiac surgery • An optimized Sn100 protocol achieved a mean SSDE of only 0.5 ± 0.1 mGy • The depiction of atherosclerosis of the thoracic aorta was similar with both protocols • The depiction of relevant thoracic pathologies before cardiac surgery was similar with both protocols.

Diagnostic accuracy of chest X-ray dose-equivalent CT for assessing calcified atherosclerotic burden of the thoracic aorta

OBJECTIVE

To determine the value of ultralow-dose chest CT for estimating the calcified atherosclerotic burden of the thoracic aorta using tin-filter CT and compare its diagnostic accuracy with chest direct radiography.

METHODS

A total of 106 patients from a prospective, IRB-approved single-centre study were included and underwent standard dose chest CT (1.7 ± 0.7 mSv) by clinical indication followed by ultralow-dose CT with 100 kV and spectral shaping by a tin filter (0.13 ± 0.01 mSv) to achieve chest X-ray equivalent dose in the same session. Two independent radiologists reviewed the CT images, rated image quality and estimated presence and extent of calcification of aortic valve, ascending aorta and aortic arch. Conventional radiographs were also reviewed for presence of aortic calcifications.

RESULTS

The sensitivity of ultralow-dose CT for the detection of calcifications of the aortic valve, ascending aorta and aortic arch was 93.5, 96.2 and 96.2%, respectively, compared with standard dose CT. The sensitivity for the detection of thoracic aortic calcification was significantly lower on chest X-ray (52.3%) compared with ultralow-dose CT (p < 0.001).

CONCLUSION

A reliable estimation of calcified atherosclerotic burden of the thoracic aorta can be achieved with modern tin-filter CT at dose values comparable to chest direct radiography. Advances in knowledge: Our findings suggest that ultralow-dose CT is an excellent tool for assessing the calcified atherosclerotic burden of the thoracic aorta with higher diagnostic accuracy than conventional chest radiography and importantly without the additional cost of increased radiation dose.

Ultra low-dose chest ct with iterative reconstructions as an alternative to conventional chest x-ray prior to heart surgery (CRICKET study): Rationale and design of a multicenter randomized trial

BACKGROUND

Stroke after cardiac surgery is a severe complication with a persistently high incidence of 1.4 - 9.7%. Postoperative strokes are mainly embolic and can be provoked by manipulation and clamping of the aorta during cardiac surgery, resulting in the mobilization of atherothrombotic material and calcifications from the aortic wall. Computed tomography (CT) can offer preoperative visualization of aortic calcifications with low radiation exposure. We hypothesize that preoperative knowledge regarding the location and extent of aortic calcifications can be used to optimize surgical strategy and decrease postoperative stroke rate.

METHODS/DESIGN

The CRICKET study (ultra low-dose chest CT with iterative reconstructions as an alternative to conventional chest x-ray prior to heart surgery) is a prospective multicenter randomized clinical trial to evaluate whether non-contrast chest CT before cardiac surgery can decrease postoperative stroke rate by optimizing surgical strategy. Patients scheduled to undergo cardiac surgery aged 18 years and older are eligible for inclusion. Exclusion criteria are pregnancy, a chest/cardiac CT in the past three months, emergency surgery, concomitant or prior participation in a study with ionizing radiation and unwillingness to be informed about incidental findings. Subjects (n = 1.724) are randomized between routine care, including a chest x-ray, or routine care with an additional low dose chest CT. The primary objective is to investigate whether the postoperative in-hospital stroke rate is reduced in the CT arm compared to the routine care arm of the randomized trial. The secondary outcome measures are altered surgical approach based on CT findings and cost-effectiveness.