Preoperative Computed Tomography Angiography Research Articles

Iterative closest graph matching for non-rigid 3D/2D coronary arteries registration

Background and objective Fusion of the preoperative computed tomography angiography and intraoperative X-ray angiography images can considerably enhance the visual perception of physicians during percutaneous coronary interventions. This technique can provide 3D information of the arteries and reduce the uncertainty of 2D guidance images. For this purpose, 3D/2D vascular registration with high accuracy and robustness is crucial for performing accurate surgery.Methods In this study, we propose an iterative closest graph matching (ICGM) method that utilizes an alternative iteration framework including correspondence and transformation phases. A coarse-to-fine matching approach based on redundant graph matching is proposed for the correspondence phase. The transformation phase involves rigid and non-rigid transformations, in which rigid transformation is calculated using a closed-form solution, and non-rigid transformation is achieved using a statistical shape model established from a synthetic deformation dataset.Results The proposed method is evaluated and compared with nine state-of-the-art methods on simulated data and clinical datasets. Experiments demonstrate that our method is insensitive to the pose of data and robust to noise and deformation. Moreover, it outperforms other methods in terms of registering real data.Conclusions Given its high capture range, the proposed method can register 3D vessels without prior initialization in clinical practice.

Doppler Ultrasound as a Unique Diagnosis Test in Peripheral Arterial Disease

The aim of this study was to analyze duplex ultrasound (DUS) and intraoperative angiography concordance for diagnosis of lower limb peripheral artery disease and its value for surgical planning. This was a prospective, observational study, including patients who underwent revascularization of the lower limbs during 2018, diagnosed by DUS only or combined with preoperative computed tomography (CT) angiography. The concordance between preoperative DUS or CT angiography and the intraoperative angiography was studied using the Cohen kappa coefficient (k). The degree of agreement between the DUS-based surgical plan and the final surgical technique was also evaluated. Fifty-one patients were included, with mean age of 71.8±11.96years (46-94); 23 had chronic kidney disease (45%). In 17 patients (34%), preoperative CT angiography was also performed. DUS showed a sensitivity of 100% (95% confidence interval (CI) [83.3-100%]), 80% (95% CI [50.21-100%,]), and 100% (95% CI [96.43-100%]) at the iliac, femoral, and popliteal sector, respectively, and a specificity of 93.55% (95% CI [83.29-100%]), 95.45% (95% CI [84.48-100%]), and 90.48% (95% CI [75.54-100%]) at the iliac, femoral, and popliteal sector, respectively. The positive predictive value for DUS was 60% (95% CI [7.06-100%]), 88.9% (95% CI [62.8-100%]), and 87.5% (95% CI [68.17-100%]) for the iliac, femoral, and popliteal sectors, respectively, whereas the negative predictive value was 100% (95% CI [98.28-100%]), 91.3% (95% CI [77.61-100%]), and 100% (95% CI, [97.37-100%]). The concordance between DUS and intraoperative angiography showed a k index of 0.587 (P=0.000) in the iliac sector, 0.799 in the femoral sector (P=0.000), and 0.699 in the popliteal sector (P=0.000). The concordance between CT angiography/intraoperative angiography had a k index of 0.71 in the iliac sector (P=0.0093), 0.566 in the femoral sector (P=0.006), and 0.5 in the popliteal sector (P=0.028). DUS-based surgical plan was accurate in 86% of cases (n=44). Our experience suggests that DUS arterial mapping of the femoral and popliteal areas is better than CT angiography and can be considered as a unique preoperative imaging test during the surgical planning in patients undergoing a lower limb revascularization procedure.

Abstract 16300: Preoperative Computed Tomography Angiography Reveals Leaflet-specific Contribution to Aortic Stenosis Influenced by Local Coronary Factors

Background: Current computed tomography (CT)-based diagnosis of severe aortic stenosis (AS) using aortic valve calcification (AVC) load does not take into account interleaflet differences in calcification and leaflet dysfunction. Objectives: We sought to assess the functional impact of these differences and identify factors that can influence calcification load in a leaflet-specific manner. Methods: We retrospectively reviewed the CT angiograms (CTA) of 170 AS patients being considered for valvular intervention and 20 control normal-valve patients. We quantified AVC load, aortic valve leaflet calcification (AVLC) load, and systolic leaflet excursion (LE sys ), and used regression analysis to investigate their interrelationships. We further performed computer simulation to examine how interleaflet differences in LE sys affect aortic valve area (AVA). Lastly, we used regression analysis to identify contributors of leaflet-specific calcification. Results: We observed significant interleaflet differences in AVLC load in AS patients, with noncoronary cusp (NCC) carrying the most load (342.0 [220.3-603.1] AU), compared to the right coronary cusp (RCC) (278.5 [168.2-492.1] AU; P < 0.001) and the left coronary cusp (LCC) (240.6 [143.1-450.3] AU; P < 0.001). However, LCC, but not NCC, was associated with the least LE sys (43.0 [38.4-49.2] °), compared to both NCC (45.2 [41.2-49.9] °; P = 0.009) and RCC (47.8 [42.1-53.0] °; P < 0.001). Computer simulation of normal valve dynamics revealed that NCC and RCC contributed 10.4 [-1.6-15.7] % more ( P = 0.004) and 10.7 [4.9-20.4] % more ( P < 0.001) to AVA than LCC. In multiple regression analysis, only NCC and RCC AVLC loads predicted LE sys (b = -0.015, P < 0.001; b = -0.020, P < 0.001), but not LCC AVLC load (b = -0.008; P = 0.065). Both ostial/proximal occlusion and ostial height of right coronary artery predicted RCC AVLC load (b = 71.508, P = 0.007; b = 10.252, P = 0.008). Conclusions: NCC and RCC should be given more weight than LCC in the evaluation of AS because of their greater AVC loads, more predictable LE sys -AVLC relationships, and greater contributions to AVA. Ostial/proximal occlusion and large ostial height of RCA should signify risk for disease progression in RCC.

Colour 3D-Reconstructed Computed Tomography Angiography Delineates Blood Flow Through Aortocaval Fistula Pre- and Post-EVAR

A 58 year old man was admitted with atrial fibrillation and lower limb swelling without abdominal pain. Computed tomography angiography (CTA) showed an isolated aortocaval fistula (ACF) secondary to abdominal aortic aneurysm (85 mm) rupture. The patient underwent urgent Gore C3 Excluder (W. L. Gore & Associates, Flagstaff, AZ, USA) endograft placement with immediate symptom resolution. Post-processing imaging software (Global Illumination Rendering v7.0; Vital Images, Canon Medical Systems, Paris, France; 2000 × 2000 pixels/300 dpi) allowed three dimensional reconstruction of aneurysm blood flow on pre-operative CTA (A), later identifying a small ACF fed by a type II endoleak (B), noted to have resolved on the two month surveillance CTA.Figure 1

Quantitative analysis of renal arterial variations affecting the eligibility of catheter-based renal denervation using multi-detector computed tomography angiography

Catheter-based renal denervation (RDN) was introduced to treat resistant hypertension. However, the reduction in blood pressure after the RDN was modest. Catheter-based RDN was performed only at main renal arteries, except for accessory and branch arteries due to the diameter being too small for the catheter to approach. Here, we retrospectively analyzed the anatomy of diverse renal arteries via 64-channel multi-detector computed tomography angiograms of 314 consecutive donors who underwent living donor nephrectomy from January 2012 to July 2017. Occurrence rates of one or more accessory renal arteries in donors were 25.3% and 19.4% on the left and right sides, respectively. Early branching rates before 25 mm from the aorta to the right and left renal arteries were 13.7% and 10.5%, respectively. Overall, 63.1% and 78.3% of donors had no accessory artery bilaterally and no branched renal artery, respectively. As a result, 47.1% had only main renal arteries without an accessory artery and early-branching artery. Approximately half of the donors had multiple small renal arteries bilaterally, for which catheter-based denervation may not be suitable. Thus, preoperative computed tomography angiography requires careful attention to patient selection, and there is a need for improved methods for denervation at various renal arteries.

Duplex ultrasound versus CT angiography for the treatment planning of lower-limb arterial disease.

This study aimed to assess the diagnostic accuracy of duplex sonography (DUS) compared with that of computed tomography angiography (CTA) in detecting occlusion and stenosis in peripheral arterial disease (PAD) in candidate patients for endovascular revascularization with intraprocedural digital subtraction angiography (DSA). The study involved 94 patients suffering from PAD who were candidates for endovascular procedures requiring DSA. They were all submitted preoperatively to DUS and CTA. Based on image analysis, five segments of the arterial tree were assessed: iliac, common femoral, superficial femoral, popliteal, and infrageniculate. According to the stenosis or occlusion degree, the arteries were rated as nonstenotic, stenotic, and occluded. The agreement between DUS and CTA findings using DSA as a reference modality was expressed as a Cohen's kappa (κ) statistic agreement. Our results show that DUS has been less accurate than CTA in evaluating iliac arterial diseases (Cohen's κ agreement of 0.91 and 1.0, respectively) when measured against DSA. We found good diagnostic concordance between DUS and DSA in detecting hemodynamic stenosis and occlusion of the femoro-popliteal axis (Cohen's κ agreement between 0.96 and 0.93). Below the knee, CTA showed even less concordance with DSA (Cohen's κ 0.75). Because of its accuracy, high-quality DUS performed by well-trained operators may therefore represent a good alternative to CTA in patients undergoing endovascular revascularization to minimize the use of contrast-enhanced radiological imaging. Nevertheless, preoperative CTA imaging is required in cases of nondiagnostic DUS or when a more complete overview of the vascular tree is needed for complex invasive interventions.

Preoperative computed tomography assessment for a deep inferior epigastric perforator (DIEP) flap: a new easy technique from the Bologna experience.

Deep inferior epigastric perforator (DIEP) flap reconstruction is the gold standard reconstructive technique for women undergoing breast cancer surgery. A preoperative computed tomography angiography (CTA)-dedicated protocol and 3D reconstructions are mandatory for correct surgical planning. To evaluate the diagnostic performance of a new preoperative CTA protocol and a new reconstruction method in the assessment of DIEP technique. A total of 263 women (median age 49 years, age range 26-73 years) underwent preoperative CTA examination before DIEP flap breast reconstruction. A CTA-dedicated protocol followed by 3D-reconstructions were performed. Identification, branching pattern, and caliber at origin were assessed for each perforator. Intraoperative findings were the standard of reference. The sensitivity, positive predictive value, and diagnostic accuracy of the preoperative CTA protocol were calculated. In 255/263 (97%) patients, the dominant perforators assessed by CTA resulted adequate for surgical reconstruction. In 260/263 (99%) cases, the imaging localization of the dominant perforators corresponded with those seen intraoperatively (mean errors ≤1 cm). The preoperative CTA imaging sensitivity, positive predictive value, and diagnostic accuracy in determining the localization of perforators were 99% (95% CI 98-100), 100% and 99% (95% CI 98-100), respectively. No statistically significant differences were found between the CTA findings and the surgical findings for the assessment of branching pattern and caliber of the dominant perforators (P < 0.001). The present protocol has demonstrated high accuracy in the CTA imaging assessment of the perforators before DIEP flap reconstruction with high reproducibility between CT and surgical findings.

Computed tomographic angiography to analyze dangerous vertebral artery anomalies at the craniovertebral junction in patients with basilar invagination

ObjectiveFailure to detect dangerous anatomic vertebral artery anomalies (AVAAs) and dangerous functional vertebral artery anomalies (FVAAs) at the craniovertebral junction (CVJ) in patients with basilar invagination (BI) can result in major complications such as intraoperative vertebral artery injury, brain infarctions, and even death. Iatrogenic vertebral artery injury is a rare but severe complication of cervical spine surgery. We aimed to evaluate dangerous vertebral artery anomalies at the CVJ in patients with BI using computed tomographic angiography (CTA). MethodsCTA images of 61 BI patients were retrospectively analyzed to evaluate AVAAs and FVAAs at the CVJ. Dangerous AVAAs include a persistent first intersegmental artery (FIA), fenestration of the vertebral artery (FEN), and posterior inferior cerebellar artery with an extradural C1/2 origin (PICA-C1/2). Dangerous FVAAs include a dominant vertebral artery (DVA) and hypoplastic vertebral artery ending in the PICA (HVA-PICA) without joining the basilar artery. ResultsOverall, 31 female and 30 male patients (mean age, 42.3 years) were included. The incidences of FIA, FEN, and PICA-C1/2 were 29.5 % (18/61), 3.3 % (2/61), and 3.3 % (2/61), respectively, whereas the incidences of DVA and HVA-PICA were 36.1 % (22/61) and 1.65 % (1/61), respectively. ConclusionDangerous vertebral artery anomalies at the CVJ have a high incidence in patients with BI. Preoperative CTA is highly recommended in such patients to identify anomalous vertebral arteries and reduce the risk of intraoperative injury.

Randomized Control Trial of the Utility of Preoperative CT-Angiography in Deep Inferior Epigastric Artery Perforator Flap Breast Reconstruction

BACKGROUND: CT-angiogram has become the preferred method for the planning of abdominal-based microsurgical breast reconstruction to gather information about location, number, caliber, and trajectory of the abdominal perforators and to decrease overall flap dissection and operating room time. However, the high-level evidence to support its utility has been limited to nonrandomized retrospective and prospective studies. METHODS: Patients undergoing deep inferior epigastric artery perforator flap breast reconstruction were prospectively randomized to preoperative CT-angiogram and no imaging groups. Patient demographics, operative times, selected row, and number of perforators for flap harvest, agreement in perforator selection between radiologist and surgeon and clinical outcomes data were collected. Two-way analysis of variance, Fischer’s exact, and Student’s t tests were used for statistical analysis. RESULTS: Overall, 37 patients with 63 flaps were included in this study. Seventeen patients had CT scan before surgery. Mean age was 50.5 ± 9.64 years. Flap dissection time was significantly shorter in the CT group (150.82 ± 17,866 versus 184.74 ± 25.125 minutes; P < 0.001). Although overall OR time was also shorter in the CT group, this only reached to a statistical significance in bilateral surgeries (575.91 ± 70.10 versus 641.87 ± 79.55; P = 0.038). Hemiabdomen side, selected DIEA row, and number of dissected perforators did not affect the overall dissection time. Complication rates were similar between the 2 groups. CONCLUSION: This prospective, randomized study demonstrates that preoperative CT-angiogram analysis of perforators decreases flap harvest and overall OR time with equivalent postoperative outcomes.

Neurophysiologic Detection of Spinal Cord Ischemia During Anterior Vertebral Tethering

Case report. The aim of this study was to present how computed tomographic angiography (CTA) and intraoperative neurophysiologic monitoring (IONM) detect spinal cord ischemia during anterior spine surgery. These data directed expedient surgical and anesthetic interventions that restored IONM signals and prevented neurologic sequalæ. Anterior vertebral tethering (AVT) is a fusionless surgical treatment of adolescent idiopathic scoliosis (AIS). AVT was performed on a skeletally immature patient with AIS. Preoperative CTA detailed location of the dominant radicular artery (DRA). Transcranial motor (tcMEP) and somatosensory (SEP) evoked potentials were monitored during operation. There was significant decline in tcMEP, but not SEP, after compression of the DRA during cable tensioning of AVT. There was complete tcMEP recovery following release of instrumentation. This article identifies a rare but potentially catastrophic vascular hazard associated with anterior spine operation, including AVT. Sacrifice of multiple unilateral segmental vessels may overwhelm the capacity of collateral spinal cord perfusion to compensate for DRA blood supply. This vascular risk may be eliminated by identifying the DRA in order that it may be preserved during the procedure. 5.

The Efficacy of a Protocol of Iliac Artery and Limb Treatment During EVAR in Minimising Early and Late Iliac Occlusion

Iliac limb occlusion (ILO) is a complication of endovascular aortic repair (EVAR) and requires re-intervention in most cases. Attention to any intra-operative defect of iliac limbs and arteries may prevent ILO. The study aimed to analyse the long term effect of an intra-operative protocol of iliac limb treatment during EVAR on ILO. Patients treated from 2012 to 2017 for abdominal aortic aneurysm (AAA) with standard EVAR were collected prospectively. Pre-operative computed tomography angiography anatomical characteristics were evaluated. The protocol for intra-operative iliac limb management was: a. pre-EVAR angioplasty of common/external iliac artery stenosis; b. precise contralateral iliac limb deployment at the same level of the flow divider; c. iliac limb kissing ballooning with high pressure non-compliant balloons; d. iliac limb stenting for residual tortuosity/kink and adjunctive external iliac stenting for residual stenosis/dissection after EVAR. ILO was evaluated at 30 days and at follow up, which was performed by duplex ultrasonography before discharge, at three, six, and 12 months and yearly thereafter. Kaplan-Meier and Cox linear regression were used. Four hundred and forty-two patients and 884 iliac limbs were included in the study. Severe iliac tortuosity and calcification were present in 15% (132/884) and 8% (70/884), respectively. External iliac angioplasty and stenting of iliac limb were performed in 2% (18/884) and 9.5% (84/884) of limbs. The thirty day mortality was 1.6%, with no ILO. At a mean follow up of 33±12 months, ILO occurred in 7/884 (0.8%) limbs of six patients. Five ILO were treated by endovascular relining, two surgically: one by femorofemoral bypass and one by surgical explant. On univariable analysis, sac shrinkage was significantly associated with ILO (HR 1, 95% CI 0.8-2.5, p=.043). A protocol of aggressive iliac limb treatment in EVAR leads to a very low rate of late ILO. The role of sac shrinkage in ILO should be investigated further.

Intraoperative Electroencephalographic Changes During Transcarotid Artery Revascularization Are More Frequent Than Previously Reported

Up to 14% of patients undergoing carotid endarterectomy with continuous electroencephalographic (EEG) neuromonitoring require shunt placement because of EEG changes. Initial studies of transcarotid artery revascularization (TCAR) found only one patient with temporary EEG changes. We report our experience with intraoperative EEG monitoring during TCAR. We conducted a retrospective review of patients from May 2017 to January 2020 who received TCAR at two urban hospitals within an integrated health care network. Data included demographic information, patient comorbidities, symptom status, prior carotid interventions, anatomic details, contralateral disease, intraoperative vital signs and EEG changes, and postoperative major adverse events (transient ischemic attack, stroke, myocardial infarction, and death) both initially and 30 days postoperatively. Fisher exact test was used for categorical data; continuous data were analyzed with Wilcoxon rank sum. A total of 89 patients underwent TCAR during the study period, of whom 71 (79.8%) had intraoperative EEG neuromonitoring; 70.8% of patients were male. Median age was 75 years (interquartile range, 68-82.5 years). Symptomatic patients accounted for 41.6% of the cohort. Of the 71 patients who had continuous neuromonitoring, 9 had EEG changes during TCAR (12.7%); changes resolved in 7 patients with pressure augmentation (2), low-flow toggle (2), and unclamping after completion of flow reversal (3). One patient who had sustained EEG changes had a new postoperative neurologic deficit. Median carotid stenosis percentage on preoperative computed tomography angiography was lower for patients with EEG changes than for those without (67% vs 80%; P = .009). Neither symptomatic carotid stenosis nor 30-day events were associated with EEG changes during TCAR (P = .49 and P = .57, respectively). Overall, there were three postoperative strokes, two postoperative deaths, and one myocardial infarction for a 30-day stroke/death/myocardial infarction rate of 7.9%. Changes in continuous EEG neuromonitoring were more frequent in our study than previously reported. Less severe carotid stenosis may be associated with a higher incidence of EEG changes. There are limited data on the prognostic ability of electroencephalography to detect clinically relevant changes during TCAR, and further study is warranted.

One-Year Carotid Duplex Ultrasound Results After Transcarotid Artery Revascularization Correlated With Retrospective Blinded Preoperative Computed Tomography Angiography Calcium Severity

Severely calcified carotid arteries have been excluded from all prior clinical trials evaluating transfemoral and transcarotid artery stenting. The objective of this study was to evaluate the effects of carotid calcification on 1-year carotid duplex ultrasound findings in routine clinical practice after transcarotid artery revascularization (TCAR).

Is CT Angiogram Sufficiently Accurate Below the Knee?

Objective: Computed tomography angiography (CTA) is a mainstay of vascular imaging in most centres nationally. In peripheral vascular disease, CTA can be difficult to interpret in the crural vessels due to their small calibre, low flow, especially with upstream disease, and calcification. The aim was to investigate whether below knee CTA was accurate enough to base clinical decisions on. Methods: The below knee images from all digital subtraction angiograms (DSAs) performed by one surgeon were reviewed and the findings were compared with pre-operative CTA. CTA scans were assessed for presence of disease, level of any occlusion, and whether there was difficulty in interpreting the CTA as a result of calcification. DSA images were assessed for discrepancy in (i) level of any occlusion, or (ii) severity of disease, as well as whether this was likely to alter management. The primary outcome was any occlusion not visible, or proximal to that seen, on CTA. Results: Images from 43 DSAs were reviewed, and 20 showed occlusion(s) either not visible, or proximal to that seen on CTA (28/129 vessels). Agreement between CTA and DSA in detecting occlusion was moderate: κ = 0.425(standard error (se)_0 = 0.082032, se = 0.073293). Sensitivity of CTA, using DSA as the reference test, was 54.93% (42.66 – 66.77) and specificity 89.66% (78.83 – 96.11). Thirty-nine per cent (17 DSAs) found at least one lesion “likely to be clinically significant or affect management”. Twelve CTAs could not be accurately interpreted due to calcification. Conclusion: Discrepancy between CTA and DSA findings is common in peripheral vascular disease. With the movement from DSA to CTA in diagnostic imaging, the importance of DSA in below knee assessment should not be discounted.

Multidisciplinary approach to treat ruptured abdominal aortic aneurysm into the vena cava.

A 63-year-old man with a ruptured abdominal aortic aneurysm (AAA) into the inferior vena cava (IVC) underwent aortobifemoral bypass and closure of the aortocaval fistula (ACF). An additional bypass graft from the right iliac limb to the right internal iliac artery was placed to avoid colonic and pelvic ischemia. Preoperative computed tomography angiography (CTA) revealed an 8.6 cm AAA with rupture into the IVC through an 8.5 mm ACF (A). In addition, there was a 5.8 cm right common iliac and a 5.3 cm left common iliac artery aneurysm (B). The patient became hemodynamically unstable during CTA, and suffered a cardiac arrest with prompt cardiac resuscitation, intubation, and immediate transfer to the operating room. Ten hours after successful surgery the patient was awake and stable. He had no cardiac history, no symptoms suggestive of coronary artery disease (CAD) and had no electrocardiographic changes. However, the troponin level increased to 217,479.7 ng/L and the creatine kinase MB level increased to 504.6 ng/mL. Coronary angiography revealed left main coronary stenosis and subocclusion of the right coronary artery (C). Percutaneous coronary revascularization was performed with implantation of drug-eluting stents in the left main and right coronary artery. The patient recovered uneventfully. The 6-month follow-up CTA demonstrated patent aortobifemoral and right internal iliac bypass grafts and the IVC without signs of stenosis (D). Written informed consent was obtained from the patient for his anonymized information to be published in this article. AAA rupture into the IVC is rare and is associated with high mortality.1Davidovic L. Dragas M. Cvetkovic S. Kostic D. Cinara I. Banzic I. Twenty years of experience in the treatment of spontaneous aorto-venous fistulas in a developing country.World J Surg. 2011; 35: 1829-1834Crossref PubMed Scopus (19) Google Scholar, 2Simons J. Baril D. Goodney P. Bertges D. Robinson W. Cronewett J. et al.The effect of postoperative myocardial ischemia on long -term survival after vascular surgery.J Vasc Surg. 2013; 58: 1600-1608Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar, 3Krievins D. Zellans E. Erglis A. Zvaigzne L. Lacis A. Jegere S. et al.High prevalence of asymptomatic ischemia-producing coronary stenosis in patients with critical limb ischemia: anatomic and functional assessment with coronary CT-derived fractional flow reserve (FFRCT).Vasc Dis Manag. 2018; 15: E96-E101Google Scholar, 4Aboyans V. Ricco J.B. Bartelink M.E.L. Björck M. Brodmann M. Cohnert T. et al.2017 ESC guidelines on the diagnosis and treatment of peripheral arterial diseases, in collaboration with the European Society for Vascular Surgery (ESVS).Eur Heart J. 2018; 39: 763-816Crossref PubMed Scopus (1389) Google Scholar Preoperative diagnosis of ACF with CTA facilitated expeditious surgical treatment in this patient. Patients who survive surgery but have biomarker evidence of myocardial injury have reduced long-term survival.2Simons J. Baril D. Goodney P. Bertges D. Robinson W. Cronewett J. et al.The effect of postoperative myocardial ischemia on long -term survival after vascular surgery.J Vasc Surg. 2013; 58: 1600-1608Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar Patients with AAA commonly have coexistent CAD. Pre-operative diagnosis of silent coronary ischemia with coronary CTA and fractional flow reserve derived from CT (FFRCT) can identify high risk patients who may benefit from coronary revascularisation.3Krievins D. Zellans E. Erglis A. Zvaigzne L. Lacis A. Jegere S. et al.High prevalence of asymptomatic ischemia-producing coronary stenosis in patients with critical limb ischemia: anatomic and functional assessment with coronary CT-derived fractional flow reserve (FFRCT).Vasc Dis Manag. 2018; 15: E96-E101Google Scholar Ruptured AAA into IVC with unsuspected CAD can be successfully treated with prompt image-based diagnosis and involvement of a multidisciplinary vascular team.4Aboyans V. Ricco J.B. Bartelink M.E.L. Björck M. Brodmann M. Cohnert T. et al.2017 ESC guidelines on the diagnosis and treatment of peripheral arterial diseases, in collaboration with the European Society for Vascular Surgery (ESVS).Eur Heart J. 2018; 39: 763-816Crossref PubMed Scopus (1389) Google Scholar

Application and prospect of preoperative computed tomographic angiography in deep inferior epigastric artery perforator flap for breast reconstruction

To generalize the application and prospect of computed tomographic angiography (CTA) in deep inferior epigastric artery perforator (DIEP) flap transfer for breast reconstruction. The related literature using CTA for DIEP flap reconstruction of breast in recent years was reviewed and analyzed. Preoperative CTA can accurately assess the vascular anatomy of the chest and abdomen wall, precisely locating the perforator in the abdominal donor site, and identifying the dominant perforator; guide the selection of intercostal space to explore internal mammary artery and internal mammary artery perforator in the chest recipient vessels. It can also reconstruct the volume of the abdominal flap with reference to the size of the contralateral breast and pre-shape the abdominal flap, which are crucial to formulate the surgical plan and improve the reliability of flap. Preoperative CTA has enormous application potential and prospects in locating donor area perforator, in selecting recipient vessels, and in evaluating breast volume for autologous breast reconstruction with DIEP flap.

Perforator Variability of the Anterolateral Thigh Flap Identified on Computed Tomographic Angiography: Anatomic and Clinical Implications.

The anterolateral thigh (ALT) flap is a useful flap with minimal donor site morbidity. Preoperative computed tomographic angiography (CTA) for lower extremity reconstruction can determine vessel integrity and plan for recipient vascular targets. This study reviews lower extremity CTAs to further characterize ALT vascular anatomy and associated clinical implications thereof. Lower extremity CTA studies were retrospectively reviewed, and information on ALT cutaneous perforator location, origin, and course was collected. A total of 58 lateral circumflex femoral artery (LCFA) systems in 31 patients were included. Average age was 38.8 ± 15.9 years with mean body mass index of 27.2 ± 5.7 kg/m2. The majority of patients were females (23, 74.2%). The LCFA most commonly originated from the profunda femoris artery (87.3%), followed by the distal common femoral artery (9.1%). On average, there were 1.66 ± 0.69 cm perforators per extremity, with an average of 5.38 cm between adjacent perforators. Perforators originated from the descending branch of the LCFA in 89.6% of studies. Perforator caliber was <1 mm (29, 30.2%), 1 to 2 mm (55, 57.3%), or >2 mm (12, 12.5%). Mean distance from the most proximal perforator to the anterior superior iliac spine was 20.4 ± 4.82 cm. Perforators were musculocutaneous (46.9%), septocutaneous (34.4%), or septomyocutaneous (18.8%). In 58.1% of patients, only one thigh had easily dissectable septocutaneous and/or septomyocutaneous perforators, in which case preoperative CTA aided in donor thigh selection. ALT flap cutaneous perforator anatomy varies considerably. Using CTA, we report on rates of septocutaneous, myocutaneous, and septomyocutaneous perforators and underscore its utility in perforator selection.

Clinical application of free fibular flap based on digital technology in mandibular defects

Objective:To investigate the application of free fibular flap based on digital technology in mandibular defects. Method:Eight cases of mandibular defects underwent virtual surgery and guide plate design before operation. The mandibular osteotomy guide plate, fibula plastic guide plate and mandibular reconstruction model were prepared by rapid prototyping technology. The individualized reconstruction titanium plates were prefabricated on the mandibular reconstruction model. Based on the guide plates and the individualized reconstruction titanium plates, the mandibular defects were repaired accurately. At the same time, CT angiography was used to observe the variation of peroneal artery. For patients with soft tissue defects, the superficial position of the point going out muscle of perforator vessels was located, and the skin flaps were designed to repair the soft tissue defect. Result:The free fibular flaps survived in all patients. The guide plates were successfully implanted, the position of the individualized reconstruction titanium plates were accurate, and the occlussions were well recovered. Preoperative CT angiography was carried out without complication in all patients, the desired anatomy was adequately demonstrated in all patients. The superficial position of the point going out muscle of perforator vessels during operation were basically in accordance with those detected by CT angiography. Conclusion:The free fibular flaps based on digital technology can successfully repair mandibular defects with good aesthetic and functional results.

Deformable Registration of Coronary Arteries with Topological Constraints for Image-Guided Vascular Interventions.

2D/3D registration of preoperative computed tomography angiography with intra-operative X-ray angiography improves image guidance in percutaneous coronary intervention. However, previous registration methods are inaccurate and time-consuming due to simple deformation and iterative optimization, respectively. In this paper, we propose a novel method for non-rigid registration of coronary arteries based on a point set registration network, which predicts the complex deformation field directly without iterative optimization. In order to maintain the structure of coronary arteries, we advance the classical point set registration network with a loss function containing global and local topological constraints. The method was evaluated on ten clinical data, and it achieved a median chamfer distance of 73.60 pixels with a run time of less than 1s on CPU. Experimental results demonstrate that the proposed method is highly accurate and efficient.

Estimation of Profunda Artery Perforator Flap Weight Using Preoperative Computed Tomography Angiography.

Given the relatively small size of thigh-based flaps and the possible necessity for a multiflap reconstruction, it is imperative to arrive at an accurate estimation of flap weight during preoperative planning. It was our objective to develop a novel technique for the preoperative estimation of profunda artery perforator (PAP) flap weight. All patients that underwent transverse PAP flap breast reconstruction at two institutions were retrospectively reviewed. Subcutaneous tissue thicknesses were measured on axial computed tomography angiography scans at several predetermined points. The distance from the inferior gluteal crease to the PAP was also recorded. Linear regression was used to estimate flap weight. A total of 18 patients (32 flaps) were analyzed. The median intraoperative flap weight was 299 g (interquartile range [IQR]: 235-408). The parsimonious model (R 2 = 0.80) estimated flap weight using the Eq. 77.9x + 33.8y + 43.4z - 254.3, where x is subcutaneous tissue thickness (cm) at the lateral border of long head of the biceps femoris at a level 4.5 cm caudal to the inferior gluteal fold, y is distance (cm) from the inferior gluteal fold to the dominant PAP, and z has a value of 1 if the patient was scanned in the supine position or 0 if prone. The aforementioned formula yielded a median estimated flap weight of 305 g (IQR: 234-402) and a median percent error of 10.5% (IQR: 6.1-16.2). The authors demonstrate a simple and accurate formula for the preoperative estimation of transverse PAP flap weight for breast reconstruction.