Preoperative Computed Tomography Angiography Research Articles

Surgical Treatment of Proximal Segmental Occlusion of the Internal Carotid Artery.

Purpose To present the feasibility, safety, and efficacy of carotid endarterectomy in patients with type II internal carotid artery occlusions, including the long-term outcomes. Methods From March 2008 to August 2015, 74 consecutive patients (48 men with a mean age of 65.1 ± 8.06 years) underwent carotid endarterectomy because of internal carotid artery (ICA) segmental occlusions. These were verified with preoperative carotid duplex scans (CDS) and CT angiography (CTA). Also, brain CT scanning was performed in all these patients. The indication for treatment was made jointly by a vascular surgeon, neurologist, and an interventional radiologist in a multidisciplinary team (MDT) context. After successful treatment, all the patients were followed-up at 1, 3, 6, and 12 months, then every 6 months thereafter. Results The most common symptom at presentation was transient ischaemic attack (TIA) in 49 patients (66.2%), followed by stroke in the past six months in the 17 remaining patients (23%). Revascularisation of the ICA with endarterectomy techniques was performed successfully in all the patients with an average clamp time of 11.9 min. All the procedures were performed under general anaesthesia in combination with a superficial cervical block. The early complication rate was 8.1% and included two cardiac events (2.7%) (one rhythm disorder and one acute coronary syndrome), three TIAs (4.1%), and one intracerebral hemorrhage (1.3%). Only one patient with the intracerebral hemorrhage died 5 days after surgery giving a postoperative mortality of 1.3% for this series. During the follow-up period (mean 50.4 ± 31.3 months), the primary patency rates at 1, 3, 5, and 7 years were 98.4%, 94.9%, 92.9%, and 82.9%, respectively. Likewise, the survival rates were 98.7%, 96.8%, 89%, and 77.6%, respectively. Ultrasound Doppler controls during follow-up detected 8 ICA restenoses; however, only 3 of these patients required further endovascular treatment. Conclusions Carotid endarterectomy of internal carotid artery (ICA) segmental occlusion is a safe and effective procedure associated with acceptable risk and good long-term results. Therefore, the current guidelines which do not recommend carotid endarterectomy in this patient group should be reassessed, with the requirement for ongoing large-scale randomized controlled trials to compare CEA with best medical therapy in this patient cohort.

Does Preoperative Computed Tomography Angiography Lead to an Increased Incidence of Postoperative Acute Kidney Injury Following Transcatheter Aortic Valve Implantation in Patients with Impaired Renal Function?

Does Preoperative Computed Tomography Angiography Lead to an Increased Incidence of Postoperative Acute Kidney Injury Following Transcatheter Aortic Valve Implantation in Patients with Impaired Renal Function?

Pre-Operative Masseter Area is an Independent Predictor of Long-Term Survival after Carotid Endarterectomy

Sarcopenia is a predictor of mortality in elderly patients. Masseter area (MA) reflects sarcopenia in trauma patients. It was hypothesised that MA and Masseter density (MD) could be evaluated reliably from pre-operative computed tomography angiography (CTA) scans and that they predict post-operative survival in carotid endarterectomy (CEA) patients. This was an observational registry study. Patients (n=242) were operated on for asymptomatic stenosis (n=32; 13.2%), amaurosis fugax (n=41; 16.9%), transient ischaemic attack (n=85; 35.1%), or ischaemic stroke (n=84; 34.7%). Internal carotid artery stenoses were graded angiographically. Intraclass correlation coefficient (ICC) was used to analyse measurement reliability by three independent observers. Cox regression analysis was used to study the effect of MA and MD on survival (hazard ratio [HR]). Median patient age was 71.0 years (interquartile range [IQR] 13.0) and follow up time was 68.5 months (range 3-163 months); at the end of follow up (1 October 2017), 104 (43.0%) patients had died according to the National Population Register. The average MA (MAavg, the mean of left and right MA [median 394.0mm2; IQR 110.1mm2]) and MD (MDavg, the mean of left and right MD [median 53.5 HU; IQR 16.5 HU]) could be measured with excellent reliability (ICC>0.865, p<.001 for all). In multivariable analyses only body surface area (BSA) (p<.001) and dental status were associated with MAavg (p=.021). Increased MAavg predicted lower mortality (HR 0.76, 95% confidence interval [CI] 0.61-0.96; p=.023) independent of age (HR 1.05, 95% CI 1.02-1.07; p=0.001), female sex, body mass index, renal insufficiency, ipsilateral stenosis, indication category, and presence of teeth. MDavg was not associated with mortality. After further adjustment, BSA (the most significant determinant of MAavg) did not alter the association between MAavg and mortality (0.75, 95% CI 0.58-0.97; p=.031). Average MA but not MD measured from the pre-operative CTA scan provides a reliable estimate of post-operative long-term survival in CEA patients independent of other risk factors, anthropometric measurements, and dental status.

Predicting the Development of Surgically Induced Chronic Kidney Disease After Total Nephrectomy Using Body Surface Area-Adjusted Renal Cortical Volume on CT Angiography.

The purpose of this study was to predict the probability of surgically induced chronic kidney disease (CKD) developing in patients who underwent total nephrectomy by measuring the body surface area (BSA)-adjusted renal cortical volume (RCV) with preoperative CT angiography (CTA). A total of 105 patients with a normal preoperative estimated glomerular filtration rate (eGFR) who underwent preoperative CTA and subsequent total nephrectomy for kidney donation (n = 67) or a renal tumor (n = 38) were included in this retrospective study. Patients were divided into group A (patients without surgically induced CKD; n = 61) and group B (patients with surgically induced CKD; n = 44) according to postoperative renal function. The preoperative and postoperative eGFR and other laboratory findings were collected, and the BSA-adjusted postnephrectomy RCV was measured using a semiautomated segmentation technique on CTA. Multiple logistic regression analysis was used to determine the formula for predicting the probability of development of surgically induced CKD; external validation was conducted using the validation dataset (n = 28). The estimated probability of surgically induced CKD developing can be calculated using the following formula: logit (probability of surgically induced CKD developing) = [1.431 × I (reason for operation was renal tumor)] + (-0.097 × preoperative eGFR) + (-0.033 × BSA-adjusted postnephrectomy RCV) + 10.937, where I denotes an indicator function (I = 1, reason for operation was renal tumor; I = 0, reason for operation was kidney donation). The optimal cutoff value derived from 10,000 bootstrapped samples was 0.444 (95% CI, 0.298-0.681). The formula was determined to be a good tool for prediction of surgically induced CKD on external validation (AUC value, 0.894). The probability of CKD developing in patients who undergo total nephrectomy may be predicted using a BSA-adjusted postnephrectomy RCV volume measured on preoperative CTA.

The Modified Arch Landing Areas Nomenclature identifies hostile zones for endograft deployment: a confirmatory biomechanical study in patients treated by thoracic endovascular aortic repair†.

Our goal was to confirm whether the Modified Arch Landing Areas Nomenclature (MALAN) for thoracic endovascular aortic repair, in which each landing area is described by indicating both the proximal landing zone (PLZ) and the type of arch (e.g. 0/I), identifies unfavourable landing zones for endograft deployment in diseased aortas. Preoperative computed tomography angiography scans of 10 patients scheduled for thoracic endovascular aortic repair for aneurysm or penetrating ulcer of the arch and with a potential hostile PLZ were reviewed. Five had proximal deployment planned in MALAN area 3/III and 5, in MALAN area 2/III. The angulation of each PLZ was calculated. Computational fluid dynamics modelling was used to compute magnitude and orientation of pulsatile displacement forces in each PLZ. Normalized values based on PLZ areas (i.e. equivalent surface traction) were calculated. Results were compared to those obtained in healthy controls stratified by the MALAN. Angulation was severe (>60°) in MALAN areas 3/III and 2/III, which was consistent with the findings obtained in healthy controls. Increased magnitude (P = 0.021) and unfavourable orientation (i.e. orthogonal to the longitudinal aortic axis) of equivalent surface traction (P = 0.011) was also found in these areas compared to the adjacent ones, following the same pattern seen in the controls. Adverse events related to proximal endograft performance were reported in 3/10 cases. This study confirms in diseased aortas initial proof-of-concept findings on the predictive value of the MALAN to identify landing areas with a geometric and haemodynamic environment hostile for thoracic endovascular aortic repair. These adverse biomechanical features may entail an increased risk of dismal endograft performance.

Preoperative Computed Tomography Angiography in Autologous Breast Reconstruction-Incidence and Impact of Incidentalomas.

Background:Incidentalomas are lesions found coincidentally during examination, imaging, or surgical procedures. Preoperative computed tomography angiography (CTA) before abdominal flap harvest for breast reconstruction can lead to identification of incidentalomas leading to the need for further investigations. The aim of this study was to examine the prevalence of incidental findings on preoperative CTA and to determine their impact on management.Methods:A retrospective chart review was performed at a single tertiary institution. CTA reports were analyzed for the presence of incidental findings and details of follow-up were studied. Logistic regression was used to identify factors associated with incidental findings.Results:One hundred eighteen patients with a mean age of 49 years were included in the study. The majority of patients underwent bilateral reconstruction (65%, n = 77) in the immediate setting (70%, n = 83). Fifty-six percentage had an incidental finding on CTA, with hepatic (20%), renal (14%), and osseous (11%) abnormalities being most common. Additional imaging including ultrasound, CT, and magnetic resonance imaging were recommended in 19 cases (16%). Additional consultations were sought for 3 patients before reconstruction (with suspicion of bone metastases, an intraabdominal mass, and suspicion of colonic malignancy, respectively). No significant surgical delay secondary to CT findings was noted.Conclusions:Incidentalomas following preoperative CTA of the abdomen/pelvis are common (56%). However, unlike previous reports, we did not observe a change in reconstructive plan following incidentaloma discovery. We recommend that all patients are counseled pre-CTA regarding the possibilities of incidentaloma detection and need for additional imaging.

Pre-operative Aneurysm Thrombus Volume, But Not Density, Predicts Type 2 Endoleak Rate Following Endovascular Aneurysm Repair

The impact of aneurysm thrombus characteristics on type 2 endoleak rate following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) is unclear. The purpose of this study is to determine the impact of pre-operative aneurysm thrombus volume and density on the incidence of type 2 endoleak following EVAR for infrarenal AAA. A retrospective analysis was completed on all patients who underwent standard EVAR at an academic medical institution between May 1, 2010 and June 1, 2016 with a minimum follow-up period of 12months. The final analysis included 170 patients. Thrombus volume and density were determined by analyzing pre-operative computed tomography angiography (CTA) scans using the TeraRecon plaque analysis module. The number and diameter of patent infrarenal aortic branch vessels were also identified. Type 2 endoleak was diagnosed by post-operative CTA, duplex ultrasound, or angiography. Over a median follow-up period of 29months, 88 (51.8%) of 170 patients had a type 2 endoleak. The thrombus volume as a proportion of the infrarenal aorta volume was significantly lower in patients with type 2 endoleak (odds ratio [OR] 0.034, 95% confidence interval [CI] 0.005-0.291, P=0.002). The number of patent lumbar arteries was significantly greater in patients with type 2 endoleak (OR 1.45, 95% CI 1.16-1.56, P<0.0005). Both variables independently predicted the incidence of type 2 endoleak in a multivariate analysis. Thrombus density was not related to the incidence of type 2 endoleak. A lower ratio of thrombus volume/infrarenal aorta volume and a higher number of patent lumbar arteries were associated with an increased incidence of type 2 endoleak. A multivariate logistic regression model was generated to pre-operatively predict the risk of type 2 endoleak. This model can guide the stratification of patients for intensity of endoleak surveillance following EVAR and consideration of pre-operative treatment.

Performance of a feature-based algorithm for 3D-3D registration of CT angiography to cone-beam CT for endovascular repair of complex abdominal aortic aneurysms

BackgroundA crucial step in image fusion for intraoperative guidance during endovascular procedures is the registration of preoperative computed tomography angiography (CTA) with intraoperative Cone Beam CT (CBCT). Automatic tools for image registration facilitate the 3D image guidance workflow. However their performance is not always satisfactory. The aim of this study is to assess the accuracy of a new fully automatic, feature-based algorithm for 3D3D registration of CTA to CBCT.MethodsThe feature-based algorithm was tested on clinical image datasets from 14 patients undergoing complex endovascular aortic repair. Deviations in Euclidian distances between vascular as well as bony landmarks were measured and compared to an intensity-based, normalized mutual information algorithm.ResultsThe results for the feature-based algorithm showed that the median 3D registration error between the anatomical landmarks of CBCT and CT images was less than 3 mm. The feature-based algorithm showed significantly better accuracy compared to the intensity-based algorithm (p < 0.001).ConclusionA feature-based algorithm for 3D image registration is presented.

Image fusion using the two-dimensional-three-dimensional registration method helps reduce contrast medium volume, fluoroscopy time, and procedure time in hybrid thoracic endovascular aortic repairs

ObjectiveThe objective of this study was to evaluate the effect of image fusion (IF) technology in thoracic endovascular aortic repair (TEVAR) on reducing radiation exposure (dose and time), amount of injected iodinated contrast medium needed, and procedure time. MethodsWe performed a review of our institutional endovascular aortic database of patients who had undergone TEVAR between 2008 and 2016 before and after the installation of a three-dimensional (3D) IF computed tomography system in our hybrid operating room. All patients were operated on using the same radiologic equipment with or without IF. ResultsThe 146 patients who had undergone elective or emergent TEVAR with preoperative computed tomography angiography done in 1-mm-thick slices were divided into two groups: the IF group (98 patients), in which TEVAR was performed using intraoperative IF with the two-dimensional-3D registration method; and 48 controls without the use of IF. The IF group received a significantly reduced dose of contrast material, with a median of 70 mL (interquartile range [IQR], 50-101 mL) compared with controls receiving 104 mL (IQR, 69-168 mL; P < .001).Patients who underwent hybrid TEVAR had a significantly reduced procedure time under IF guidance (n = 25) compared with controls (n = 11; median, 162 minutes [IQR, 139-199 minutes] vs 213 minutes [IQR, 189-298 minutes]; P = .015). In addition, the intraoperative fluoroscopy time was reduced to 9 minutes (IQR, 6-13 minutes) vs 23 minutes (IQR, 12-45 minutes; P < .005). However, the radiation dose (dose-area product) was similar for the two groups (P = .37).In patients who underwent plain TEVAR (n = 74) without a carotid-subclavian bypass, the IF group needed significantly less contrast material (median, 64 mL [IQR, 43-81 mL]) compared with the control group (median, 98 mL [IQR, 60-180 mL]; P = .003), whereas intraoperative radiation exposition, procedure time, and fluoroscopy time did not statistically significantly differ between the two groups. ConclusionsThe IF technology using the two-dimensional-3D registration method was associated with reduced intraoperative contrast material volume in performing TEVAR. IF seemed to shorten the operation and radiation times in the more complicated (hybrid) TEVAR cases. However, a prospective study is needed to look at the dose-area product, fluoroscopy time, and procedure time in a larger cohort of patients.

The Role of CT Angiography in Assessing Deep Inferior Epigastric Perforator Flap Patency in Patients With Pre-existing Abdominal Scars

BackgroundAbdominal scars can affect the patency of deep inferior epigastric artery (DIEA) perforators and are a concern when planning free flap breast reconstruction (FFBR). Computed tomography angiography (CTA) is routinely used for preoperative DIEA flap imaging. We investigated CTA utility in predicting the most clinically useful DIEA perforators in scarred abdomens. MethodsA single surgeon's CTA FFBR patients were studied. All were imaged by one radiologist. CTA reports, abdominal scars, and flap intraoperative details were analyzed. The operative findings were then correlated with the CTA “predictions.” ResultsA hundred and six patients with preoperative CTAs underwent 132 FFBRs, 44% (58) from scarred and 56% (74) from virgin abdomens. All flap transfers were successful. Concordance between perforators identified by CTA preoperatively and those selected by the surgeon intraoperatively was 95% (scarred 93%; non-scarred 96%, P = 0.470). There was a significant difference in the proportion of single-perforator flaps between the two groups (scarred 46%; non-scarred 28%, P = 0.041). “Scarred” flaps were heavier (789 vs 676 g, P = 0.0244) than those harvested from virgin abdomens. ConclusionsCTA accurately predicted perforator choice in flaps from scarred and virgin abdomens. “Scarred” flaps are more likely to be heavier and based on one perforator suggesting that scarring may have an effect on intraflap vascular anatomy. Further investigations are needed to delineate the mechanism by which this occurs.

Pulmonary Embolism After Endovascular Aortic Repair, a Retrospective Cohort Study

Endovascular aortic repair (EVAR) is associated with an increased risk of pulmonary embolism, which is often clinically silent and therefore difficult to recognise. The aim was to investigate the incidence of pulmonary embolism after EVAR using routinely performed pre- and post-operative aortic computed tomography angiography (CTA), and the association between pulmonary embolism and mortality. This single centre retrospective cohort study included adult patients who underwent EVAR in the University Medical Centre Utrecht between January 2010 and July 2015 and who had a total aortic, thoracic aortic, or pulmonary CTA within one month post-operatively. Baseline and mortality data were obtained by reviewing hospital and general practitioner records. The primary outcome was pulmonary embolism within one month after surgery. Secondary outcomes were 30 day and six month mortality. During the study period, 526 EVARs were performed. Seventy-four of these procedures were included in the analysis of which there were 40 thoracic and 34 abdominal EVARs. In nine patients (12%, 95% CI 7-22) pulmonary embolism was observed of which one was central, two were segmental, and six were subsegmental. Seven were clinically silent and two were present on the pre-operative CTA. Thirty day mortality was significantly higher in patients with pulmonary embolism (relative risk 14.4, 95% CI 1.4-143, p=.037) though none of the deaths seemed directly attributable to it. This study, although preliminary, suggests that silent pulmonary embolism after EVAR occurs in approximately one in 10 patients, despite routine thrombo-embolism prophylaxis. Pulmonary embolism was associated with a higher 30 day mortality risk yet it was not the cause of death in any of these patients.

Endovascular repair of type B aortic dissection with the restrictive bare stent technique: morphologic changes, technique details, and outcomes.

PurposeThe aim of this study was to present our experience and assess the morphologic changes of the descending aorta after the restrictive bare stent (RBS) technique in the treatment of type B aortic dissection (TBAD).Patients and methodsA retrospective study was conducted of 22 consecutive patients with TBAD who underwent RBS treatment between February 2012 and June 2016. Indications for the RBS procedure included radiological evidence of true lumen (TL) compression or collapse and/or tortuosity index (TI) of the descending aorta >1.4. Technique success, descending aorta morphology, and clinical outcomes were evaluated.ResultsThe technical success rate was 100%. Patients treated with the RBS technique were often accompanied by TL collapse (45.5%) or TI >1.4 (59.1%). One-month postoperative computed tomography angiography showed that the taper ratio, oversizing ratio of the stent graft, and TI values were significantly decreased compared with preoperative computed tomography angiography values (P<0.05). The 30-day mortality rate was 0%. In total 95.2% had a thrombosed false lumen in the segment of aortic coverage, and TL diameters were increased in 40.3%±11% (mean ± SD) and 37.5%±17.9% of patients in the thoracic and abdominal segments, respectively. During the follow-up from 16 to 64 months (33±19 months), no distal stent graft-induced new entry, endoleak, and paraplegia were observed. One patient died from rupture of a chronic TBAD with aneurysm degeneration.ConclusionMid-term outcomes showed RBS to be a flexible and feasible approach to repair TBAD. RBS corrects the descending aorta morphology and promotes TL expansion in most patients, but the rupture of chronic TBAD with aneurysm degeneration was not prevented in all patients.

NESVS25. Most Patients Are Eligible for Transcarotid Revascularization Despite Its Anatomic Restrictions

Transcarotid artery revascularization (TCAR) has emerged as an alternative to transfemoral carotid artery stenting (CAS). We evaluated how many patients with carotid stenosis would qualify for TCAR on the basis of anatomic criteria. We performed a retrospective review of consecutive patients who underwent carotid endarterectomy or CAS between 2012 and 2015. Patients were excluded if computed tomography angiography of the neck within 6 months of the procedure was unavailable. We assessed eligibility of the patients on the basis of the instructions for use of the ENROUTE Transcarotid Neuroprotection System (Silk Road Medical, Sunnyvale, Calif). Patients were deemed ineligible for TCAR if the target internal carotid artery diameter was not between 4 and 9 mm, the clavicle to carotid bifurcation distance was <5 cm, or the intended common carotid artery (CCA) puncture site had significant plaque. We also evaluated the proportion of CCAs that had access site depth ≥4 cm because of the increased complexity of the procedure. Of 478 patients examined, 118 had preoperative computed tomography angiography. All carotid arteries had internal carotid artery diameters between 4 and 9 mm, 74% had a clavicle to carotid bifurcation ≥5 cm, and 96% had minimal or no plaque at the CCA puncture site, resulting in 72% of patients being eligible for TCAR. Of carotid arteries eligible for TCAR, 13% were considered more challenging, given CCA depth ≥4 cm; but of these arteries, only 3.4% had depth ≥4.5 cm, and 39% had a longer clavicle to bifurcation distance of >6 cm. Patients who were ineligible for TCAR were older (72.5 ± 6.8 years vs 69.1 ± 9.2 years; P < .01) and more often had hyperlipidemia (95.5% vs 80.5%; P < .01) and chronic obstructive pulmonary disease (25.4% vs 8.9%; P = .001) but were less likely to have diabetes (25.4% vs 40.8%; P< .03) or to be taking beta blockers (50.7% vs 65.1%; P = .04). Twenty percent of patients were at high risk for transfemoral CAS based on presence of type III aortic arch (7.2%), severe aortic arch calcification (4.5%), tandem CCA lesions (6.4%), or moderate to severe stenosis at the carotid ostium (9.7%). Of the transfemoral CAS high-risk patients, 63% were eligible for TCAR. Of patients >80 years old, 64% were eligible for TCAR. The majority of carotid arteries in patients selected for revascularization meet TCAR eligibility.

Usefulness of preoperative three-dimensional volumetric analysis of carotid body tumors.

The Shamblin classification is the commonest method to predict complications and outcomes during carotid body tumor (CBT) resection. The aim of this study is to describe the utility of the three-dimensional volumetric reconstruction (3DVR) analysis of the CBT and its relationship with postoperative outcomes. Preoperative computed tomography angiography (CTA) was obtained to perform 3DVR of the CBT. Imaging data were analyzed and correlated with surgical outcomes: estimated blood loss (EBL), surgical time (ST), and hospital length of stay (HLOS). The Pearson test was used to determine the correlation between volume and postoperative outcomes. Fifty-seven patients were studied, 13 had Shamblin type I tumors with a mean 3DVR of 7.69cm3 (standard deviation [SD 8.27]), 21 were type II with a mean 3DVR of 15.57cm3 (SD 8.40), and 23 were type III with a mean 3DVR of 30.58cm3 (SD 20.16). EBL mean was 559milliliters (mL) (standard error [SE] 80.44), the mean ST of resection was 202min (SD 67), and the mean HLOS was 5.8days (SD 3.23). The Pearson test showed a correlation of r = 0.69 (p < 0.0001) between 3DVR and EBL, a r = 0.4 (p = 0.05) was obtained between 3DVR and ST, and finally, a r = 0.3 (p = 0.05) between 3DVR and HLOS was obtained. The preoperative 3DVR determination of CBTs allows to analyze possible predictors of surgical outcomes. We found a positive correlation between the 3DVR volume and EBL. Further research is necessary to validate this method in the evaluation of these rare neoplasms.

Predicting venous congestion before DIEP breast reconstruction by identifying atypical venous connections on preoperative CTA imaging.

Venous congestion is the principle cause of flap failure after microsurgical breast reconstruction. We aim to correlate preoperative computed tomography angiography (CTA) findings with postoperative venous congestion to predict patients at risk of congestion. All patients undergoing deep inferior epigastric perforator (DIEP) breast reconstruction between August 2009 and August 2013 underwent preoperative CTA and prospectively entered the study. Patients with postoperative venous congestion were matched with a similar cohort of complication-free patients. Preoperative CTAs were randomized and re-interpreted by a radiologist, blinded to the subsequent clinical outcome. Inter-group comparisons were performed. Two hundred and forty DIEP flaps were performed in 202 patients over the 4-year study. Venous congestion affected 15 flaps (6.3%). Preoperative CTA showed significantly more atypical venous connections between deep and superficial systems in congested flaps compared to controls (66.7% vs. 8%; P < .0001), with a positive predictive value of 83%. Atypical connections were narrow, tortuous, or incomplete. Patients with congestion-free flaps had more normal connections (80% vs. 26.7%; P < .001) and more cranial perforators (P = .02). Similar CTA findings between groups included perforator size and lateral position, superficial inferior epigastric vein size, crossing of midline, and absent connections (P > .05). Preoperative CTA identifies atypical venous connections between deep and superficial systems that increase the risk of postoperative DIEP congestion five-fold. Identifying atypical venous connections maximizes the chances of flap survival and minimizes complications for patients considering DIEP breast reconstruction.

Anatomic Suitability for Standard, “Off-the-Shelf” Thoracic Single Side-Branched Endograft in Patients With Type B Aortic Dissection

Treatment of type B aortic dissections with thoracic endovascular aortic repair (TEVAR) has been adopted in many centers with the goal of covering the proximal entry tear. Coverage of the left subclavian artery is commonly required to achieve a dissection-free proximal seal zone. A novel thoracic single side-branched (TSSB) endograft offers a potential off-the-shelf option to achieve total endovascular incorporation of the left subclavian artery during zone 2 TEVAR. The aim of this study was to determine what percentage of patients with type B aortic dissection who require zone 2 TEVAR meet the anatomic requirements for this device. All consecutive patients undergoing TEVAR for type B aortic dissections at a single institution from 2006 to 2016 were evaluated. Three-dimensional centerline reconstruction of preoperative computed tomography angiography was performed to identify the diameter of the aorta, distances between branch vessels, diameter of the target branch vessel, and location of the primary entry tear. Only patients who required zone 2 TEVAR were included in the analysis. The primary outcome was percentage of patients who met all anatomic requirements for the TSSB endograft. The specific requirements leading to nonsuitability were also calculated. Eighty-seven patients who underwent TEVAR for type B aortic dissection were reviewed; 57 of 87 would have required zone 2 TEVAR. Indications for TEVAR were malperfusion (12), aneurysm (15), persistent pain (22), rupture (3), uncontrolled hypertension (5), and other (3). Mean follow-up was 19 months (range, 1-72 months). Only 17 patients (30%) met all the requirements for anatomic suitability (Fig). The reasons for failing anatomic suitability were covered stent graft length proximal to the branch portal (61%), aortic diameter at the proximal seal zone (11%), left subclavian diameter (16%), left subclavian length to its first branch (14%), and access vessel diameter (40%). Although the standard TSSB endograft can allow a more proximal seal zone and eliminate the need for open aortic arch debranching, only 30% of patients with type B dissection who require zone 2 TEVAR meet all the anatomic requirements for this device. The most common reason for failure of anatomic suitability is the proximity of the left carotid to the left subclavian origin.

Predicting Factors Associated with Postoperative Hypotension following Carotid Artery Stenting

Prolonged hemodynamic instability after carotid artery stenting (CAS) has been associated with increased incidence of stroke and other major adverse events. The objective of this study is to determine the factors associated with hypotension following CAS. In particular, this study evaluates whether involvement of the carotid bifurcation/bulb and degree of calcification can predict postoperative hypotension. A retrospective review of 90 CASs performed in 88 patients at a single tertiary center was completed. In patients with proximal internal carotid stenosis involving the carotid bifurcation, the extent of bifurcation/bulb calcification on preoperative computed tomography angiography was assessed using a scoring system. Calcium scores were assigned based on the percent of circumferential calcification of carotid bifurcation as follows: grade 1, <10%; grade 2, 10-50%; grade 3, 50-90%; and grade 4, >90%. Perioperative factors associated with prolonged postoperative hypotension requiring vasopressor infusion were analyzed. Overall, postoperative hypotension requiring vasopressors occurred in 26 (28.9%) of CAS. There were no differences in baseline demographics, comorbidities, or CAS indication between patients who required postoperative vasopressors for hypotension and those who did not. The majority of patients (64.4%) were on 2 or more antihypertensive medications preoperatively. Stenosis involved carotid bifurcation in 64 (71.1%) cases. Of these, 27 (42.2%) were grade 1, 19 (29.7%) were grade 2, 10 (15.6%) were grade 3, and 8 (12.5%) were grade 4 based on our calcium scoring system. On risk-adjusted analysis, carotid bifurcation/bulb involvement (adjusted odds ratio [aOR] 4.5, 95% confidence interval [CI] 1.1-18.5) and preoperative regimen of 2 or more antihypertensives (aOR 4.2, 95% CI 1.1-16.0) were independent predictors of hypotension requiring vasopressors following CAS. Among patients with carotid bifurcation involvement, severity of calcium score was not a significant predictor of postoperative hypotension. CAS for carotid stenosis involving the carotid bifurcation/bulb is associated with a higher risk for postoperative hypotension requiring vasopressors. Patients with preoperative hypertension requiring 2 or more antihypertensive medications are also at increased risk. However, severity of carotid bifurcation calcification is not a significant predictor of need for postoperative vasopressors.

Aortic Arch Debranching With Thoracic Endovascular Aortic Repair and Simultaneous Coronary Bypass Grafting

Recent advances have allowed simultaneous hybrid repair with open surgical arch debranching and thoracic endovascular stent placement. We describe an asymptomatic patient with a degenerative aneurysm and concurrent coronary disease who successfully underwent a hybrid aortic arch and descending aorta repair and coronary revascularization. A 78-year-old man presented with a distal aortic arch aneurysm and two-vessel coronary disease. Preoperative computed tomography angiography demonstrated a fusiform aortic aneurysm involving the left carotid and subclavian arteries and proximal descending aorta. Catheterization revealed severe left anterior descending and diagonal branch coronary disease. After cardiopulmonary bypass was initiated, the left anterior descending and diagonal arteries were bypassed with saphenous venous grafts. Two openings were created at the sinotubular junction proximally, and coronary anastomoses were completed. Trifurcation graft (TG) with a separate branch for stent delivery was anastomosed to the proximal ascending aorta. The proximal clamps were then removed. The innominate artery was divided between clamps and then anastomosed to the main limb of the TG. Antegrade cerebral perfusion was established through the anastomosis. Next, the left carotid artery was anastomosed to the second limb of the TG, and antegrade cerebral perfusion was initiated using both arteries. Secondary to extensive atherosclerotic disease, the left subclavian artery was exposed using a left infraclavicular incision. The left subclavian was divided and then ligated at its origin. The third limb of the TG was brought into the left side of the chest and anastomosed to the subclavian artery. The patient was weaned off cardiopulmonary bypass. Initial aortic luminal flap noted the true lumen to be concave. A 40-mm × 15-cm Gore Thoracic TAG endoluminal stent graft (W. L. Gore & Associates, Flagstaff, Ariz) was deployed in the descending aorta proximal to the celiac artery under fluoroscopic guidance through a side branch of the TG. A second 45-mm × 20-cm Gore graft was deployed distal to the TG with significant overlap with the previous graft. Postprocedure completion aortography demonstrated no endoleak, and intravascular ultrasound noted the true lumen to be convex. One-month follow-up computed tomography scan showed the endograft without endoleak and patent bypass grafts. A hybrid approach allows the repair of the distal aortic arch and descending aorta as a one-stage procedure.

Indocyanine Green Tissue Angiography Can Reduce Extended Bowel Resections in Acute Mesenteric Ischemia

PurposeSurgical exploration and bowel resection are frequently required for treating non-occlusive mesenteric ischemia. Intraoperative evaluation of intestinal perfusion is subjective and challenging. In this feasibility study, ICG fluorescence angiography was performed in order to evaluate intestinal perfusion in patients with acute mesenteric ischemia. MethodsThis is a retrospective analysis of 52 patients who were operated for acute mesenteric ischemia using ICG fluorescence angiography. Patients with occlusive disease requiring recanalization were excluded. The SPY and PinPoint imaging systems were used for open and laparoscopic surgery, respectively. Intraoperative macroscopic assessment of perfusion was compared with the ICG angiography results. ResultsSurgical exploration was performed for ischemia of the colon (n = 12), the small bowel (n = 23), or both (n = 16). One patient had ischemia of the esophagus and stomach. All patients had a preoperative CT angiography to rule out stenosis or occlusion of the mesenteric vessels. In 18 cases (34.6%), ICG fluorescence angiography provided information that was supplemental to macroscopic evaluation, but most patients did not survive the postoperative course. However, in six of those cases (11.5%), ICG angiography led to a major change in operative strategy resulting in a significant clinical benefit for those patients. For two cases, ICG fluorescence produced false negative results. DiscussionICG tissue angiography is feasible and technically reliable for evaluating intestinal perfusion in acute mesenteric ischemia and led to a significant clinical benefit in 11% of our patients. A relevant discrepancy between surgical visual assessment and fluorescence angiography was found in 35% of the cases, which may help to define resection margins more accurately and thus support surgical decision-making.

Incomplete circle of Willis is associated with a higher incidence of neurologic events during carotid eversion endarterectomy without shunting

ObjectiveA complete circle of Willis (CoW) is considered an important collateral network to maintain blood flow during cross-clamping in carotid endarterectomy (CEA). The aim of this study was to evaluate the impact of an incomplete CoW with isolated middle cerebral artery (iMCA) on immediate neurologic events (INEs) after CEA. MethodsWe prospectively collected the clinical data and outcomes of 902 patients who underwent CEA under general anesthesia between 2013 and 2015. All patients had preoperative computed tomography angiography of the extracranial and intracranial cerebral circulation. Indications were asymptomatic (52%) and symptomatic (48%) carotid artery disease. Patients who had CEA with shunt (n = 35) and those with inadequate intracranial imaging to assess CoW were excluded (n = 322) only. Computed tomography angiography images were reviewed retrospectively and independently by two vascular radiologists who were blinded for treatment outcomes. Imaging assessment included the vertebral and carotid circulation and each segment of the CoW, which was classified as normal, hypoplastic (diameter < 0.8 mm) or absent. The ipsilateral MCA was considered isolated if there was an absence of the anterior and posterior communicating branches from the contralateral carotid or posterior circulations. INE was defined as any transient ischemic attack (TIA) and stroke diagnosed immediately after the procedure. ResultsOf the 545 included patients (331 males; mean age, 69 ± 8 years), 12 (2.2%) had a stroke in the postoperative period. There were 20 INEs (8 strokes and 12 TIAs). A complete CoW was rare; it was only detected in 19 patients (3.5%) and an iMCA was found in 34 patients (6.3%). When at least one collateral circulation was complete (in 330 patients), we observed only four INEs (1.2%). Of the 34 patients with an iMCA, 8 (24%) had INE (6 TIAs and 2 strokes). Overall, iMCA was an independent predictor of INEs (odds ratio, 11.12; 95% confidence interval, 3.57-35.87; P < .001). With logistic regression, the model included hypertension, smoking, diabetes, hyperlipidemia, carotid clamping time (minutes), contralateral significant internal carotid artery stenosis of greater than 90%, ipsilateral significant internal carotid artery stenosis of greater than 90%, preoperative symptoms in 6 months, and iMCA; above iMCA only symptomatic patients had significant risk (odds ratio, 3.34; 95% confidence interval, 1.19-9.73; P = .02), whereas all other parameters were not significant. ConclusionsAn iMCA carries more than a 10-fold higher the risk of INEs after CEA with cross-clamping without shunt protection. In these patients, routine shunting is recommended to prevent INEs.