Aortic Bypass Research Articles

Outcomes of aortic coarctation surgical repair in adolescents and adults.

Coarctation of the aorta (CoA) in adolescents and adults is relatively rare. Several operative techniques have been reported, but there is no consensus. From November 1994 to July 2018, a total of 24 adolescents and adults underwent CoA repair. The mean age at operation was 29.9 ± 15.1; 19 (79%) patients were older than 18. Sixteen (67%) patients had arterial hypertension, 5 (21%) patients had bicuspid aortic valve, 4 (17%) patients had descending aneurysm, 2 (8%) patients had ascending aneurysm, 2 (8%) patients had patent ductus arteriosus and 1 (4%) patient had atrial septal defect. Three patients had prior surgery (2 CoA repair, 1 ventricular septal defect repair). Surgical corrections included extra-anatomical bypasses in 12 (50%) patients (9: left subclavian artery to descending aorta bypass, 2 proximal-to-distal coarctation bypasses, 1 ascending-to-descending aortic bypass), end-to-end anastomosis in 6 (25%) patients, resections and interpositions of a tube graft in 5 (21%) patients and arch augmentation with a tube graft in 1 (4%) patient. The mean follow-up duration was 6.2 ± 5.1 years. No mortality was observed. No patient required reoperation or reintervention. The mean upper extremity systolic pressure significantly decreased from 142.4 ± 30.3 mmHg preoperatively to 121.1 ± 15.9 mmHg postoperatively (P = 0.002). Arterial pressure gradient between upper and lower extremities significantly decreased from 50.0 ± 21.8 mmHg preoperatively to 9.7 ± 13.5 mmHg postoperatively (P < 0.001). Among patients undergoing left subclavian artery to descending aorta bypass, 8 patients underwent ankle brachial pressure index evaluation. Postoperative mean right- and left-sidedankle brachial pressure index were 0.96 ± 0.16 and 0.94 ± 0.11, respectively. All grafts were patent at the last follow-up. CoA repair in adolescents and adults showed good outcomes. Left subclavian artery to descending aorta bypass grafting is safe and effective for managing CoA in adolescents and adults.

Longitudinal computational fluid dynamics study of stenosis and aneurysmal degeneration of an aortorenal bypass.

Saphenous vein graft (SVG) bypass placement is regarded as the optimal option for renal artery stenosis, which usually causes secondary hypertension and poor renal perfusion. Using computational fluid dynamics, this study aimed to investigate the underlying hemodynamic mechanism of the vein aneurysm and stenosis after aortorenal bypass surgery. Three-dimensional models were reconstructed based on computed tomographic angiography images of a 20-year-old female patient who suffered from uncontrollable hypertension using the image processing package Mimics (Materialise). The morphology and hemodynamic parameters in the healthy state, at initial presentation and at post-operative 9-month and 2-year follow-ups after surgery were analysed. The hemodynamic parameters became normal in the left and right renal arteries after bypass surgery. However, flow separation and stagnation occurred at the post-operative 9-month aorta-vein anastomosis, which caused asymmetrical flow and extremely high wall shear stress (WSS) and WSS gradients at the outflow vein tract, where the stenosis occurred 2years later. In addition, the graft bending produced an asymmetrical flow pattern downstream. This research revealed that the abnormal hemodynamics, including flow separation and extremely high WSS values and gradients, caused by the retrograde flow of aortorenal bypass may be responsible for the SVG degeneration. In addition, flow asymmetry due to vessel bending is a potential risk factor for SVG aneurysm dilation.

Matching Static and Dynamic Compliance of Small‐Diameter Arteries, with Poly(lactide‐co‐caprolactone) Copolymers: In Vitro and In Vivo Studies

Mechanical mismatch between vascular grafts and blood vessels is a major cause of smaller diameter vascular graft failure. To minimize this mismatch, several poly-l-lactide-co-ε-caprolactone (PLC) copolymers are evaluated as candidate materials to fabricate a small diameter graft. Using these materials, tubular prostheses of 4 mm inner diameter are fabricated by dip-coating. In vitro static and dynamic compliance tests are conducted, using custom-built apparatus featuring a closed flow system with water at 37 °C. Grafts of PLC monomer ratio of 50:50 are the most compliant (1.56% ± 0.31∙mm Hg-2 ), close to that of porcine aortic branch arteries (1.56% ± 0.43∙mm Hg-2 ), but underwent high continuous dilatation (87 µm min-1 ). Better matching is achieved by optimizing the thickness of a tubular conduit made from 70:30 PLC grafts. In vivo implantation and function of a PLC 70:30 conduit of 150 µm wall-thickness (WT) are tested as a rabbit aorta bypass. An implanted 150 µm WT PLC 70:30 prosthesis is observed over 3 h. The recorded angiogram shows continuous blood flow, no aneurysmal dilatation, leaks, or acute thrombosis during the in vivo test, indicating the potential for clinical applications.

Initial experience with the Perceval S sutureless aortic valve.

IntroductionSurgical treatment of the aortic valve represents the gold standard, and thus aortic valve replacement (AVR) is one of the most commonly performed cardiac operations.AimTo evaluate the early outcome of aortic valve replacement with the Perceval S sutureless aortic bioprosthesis.Material and methodsThis was a retrospective analysis of 24 patients (mean age: 71 ±5 years), who underwent aortic valve replacement with a Perceval S valve. Concomitant coronary artery bypass grafting (CABG) was performed in 9 patients. Patients were evaluated preoperatively, at hospital discharge, and once during follow-up.ResultsA total of 15 of 24 patients underwent isolated sutureless aortic valve replacement (mean aortic cross-clamp time: 60 ±14 minutes; mean bypass time: 90 ±23 minutes). Coronary bypass grafting was performed in 9 patients (mean aortic cross-clamp time: 78 ±23 minutes; mean bypass time: 111 ±31 minutes). Hospital mortality was nil. Mean and peak transvalvular pressure gradients were 10 ±2 mm Hg and 21 ±3 mm Hg at follow-up, respectively. Moderate or severe aortic regurgitation did not develop in any patients during the follow-up period. No valve thrombosis, thromboembolic events, or structural valve deterioration were observed.ConclusionsIn our experience with sutureless aortic valve replacement, the surgical procedure is shown to be safe. The early haemodynamic performance seems favourable. By shortening the aortic cross-clamp and bypass times we can notice advantages, especially in high-risk patients. Minimally invasive access seems to be facilitated. Larger studies are needed to confirm our data and determine the long-term durability of the Perceval S sutureless bioprosthesis.

A Case of Descending Aorta-abdominal Aorta Bypass with Reconstruction of Bilateral Renal Artery for a Patient with Atypical Coarctation

A Case of Descending Aorta-abdominal Aorta Bypass with Reconstruction of Bilateral Renal Artery for a Patient with Atypical Coarctation

Laparoscopic Retroperitoneal Washout of an Infected Aorto-Bifemoral Graft: A Novel Technique

Aortic prosthesis infection is a challenging complication of aortic bypass surgery with high morbidity and mortality. We report a laparoscopic washout of an infected aorto-bifemoralperigraft collection with radiologic guidance using a nephroscope. The track was dilated with Endouro balloon and sheath to allow access. The cavity was copiously irrigated with saline and aqueous iodine solution. Surveillance computed tomography scan showed no new collection, thrombosis, aneurysm or fistula from the bypass graft. Bilateral lower limbs remained well perfused. Minimally invasive retroperitoneal washout may be a viable alternative to graft explant and extra-anatomical bypass in aortic graft infection.

Influence of age factor and age-associated predictors on remote results of coronary artery bypass grafting

This study was undertaken to analyse long-term survival and its predictors, depending on age of patients who underwent isolated coronary aortic bypass grafting. Our study included a total of 177 consecutive patients operated on during 2014. For the purpose of statistical analysis, the patients were divided into two groups according to their age at the time of surgery: <60 years (n=96) and >60 years (n=81). The mean age in the groups <60 years and >60 years amounted to 54.5±2.9 years and 63.5±2.5 years, respectively. All data were obtained from the patients' medical histories, outpatient follow-up records, and operative reports. The average duration of follow-up in the overall cohort amounted to 5.1±1.7 years. Chronic obstructive pulmonary disease, peripheral artery disease, and acute impairment of cerebral circulation were of significantly less common occurrence in the younger patient cohort. However, the frequency of a body mass index of ≥30 kg/m2, unstable angina, previously endured myocardial infarction and left ventricular systolic dysfunction in the preoperative period appeared to be significantly higher in this population. At 5 years after surgery, freedom from survival amounted to 94.8% in patients younger than 60 years (5 patients) and to 90.1% (8 patients) in those aged 60 years and older (p<0.001). Based on the findings of a multivariate analysis, independent predictors of mortality turned out to be a history of myocardial infarction, chronic kidney disease, diabetes mellitus, chronic obstructive pulmonary disease, lesions of peripheral arteries and the trunk of the left coronary artery. The area under the receiver operating characteristic curve was 0.834 (p<0.001, 95% CI: 0.724-0.902). Despite the fact that coronary artery bypass grafting is an effective method of treatment of ischaemic heart disease for both groups, special attention should be paid to the development and improvement of preventive strategies aimed at decreasing the impact of specific risk factors for cardiovascular diseases such as diet, lifestyle, weight control, and more aggressive medical therapy in younger patients. It is necessary to elaborate a reasonable strategy and optimization of the choice of an optimal approach to myocardial revascularization for elderly patients with multivessel and truncal lesions of coronary arteries, which are potential risk factors of death in the postoperative period.

The Association between Earlobe Creases and Cardiovascular Events in Japanese Hemodialysis Patients: A Prospective Cohort Study.

Objective The earlobe crease, a wrinkle extending from the tragus to the outer border of the earlobe, is a well-known surrogate marker for a high risk of cardiovascular disease. However, information is lacking about its association with cardiovascular events among hemodialysis patients, who already have an increased risk of cardiovascular disease. We tested the hypothesis that earlobe creases are independently associated with the risk of cardiovascular events among Japanese hemodialysis patients. Methods This prospective cohort study followed 247 adult hemodialysis patients with no history of cardiovascular disease for 4 years. The presence of earlobe creases was defined by two researchers using photos of patients' earlobes on both sides while blinded to one another's assessments and clinical data. The primary outcome was defined as the first fatal or nonfatal cardiovascular event (myocardial infarction, ischemic or hemorrhagic stroke, or peripheral vascular disease requiring aortic or peripheral vascular bypass surgery or below- or above-the-knee amputation). A Fine-Gray competing risks regression model was used to examine the association between earlobe creases and cardiovascular events. Results During the 4-year follow-up period, 43 patients suffered cardiovascular events. After the competing risk of non-cardiovascular death was accounted for, patients with earlobe creases had an increased cumulative incidence of cardiovascular events compared to those without earlobe creases (subhazard ratio =2.04, 95% confidence interval: 1.09 to 3.82). This association was no longer significant after adjusting for age. Conclusion Earlobe creases were not independently associated with cardiovascular events among Japanese hemodialysis patients, suggesting that these marks are simply indicative of advanced age.

Enhanced endothelial cell activity induced by incorporation of nano-thick tantalum layer in artificial vascular grafts

Expanded polytetrafluoroethylene (ePTFE) has been successfully used as an artificial vascular graft material owing to its unique merits of fibrous structure, chemical stability, physical robustness, and nontoxicity. However, its insufficient endothelial cell affinity arising from its highly hydrophobic surface nature induces early thrombus formation and development of neointimal hyperplasia, leading to poor long-term patency rates. In this study, we demonstrate a novel rapid surface modification technique, termed as sputtering-based plasma immersion ion implantation (S-PIII), to elicit favorable vascular responses on the ePTFE surface. This technique enables rapid ion implantation of biologically compatible tantalum (Ta) into ePTFE surfaces, generating a nano-thick Ta-rich surface layer (<30 at.%) without any structural defects or loss of ePTFE’s fibrous morphology. Surface properties of ePTFE, such as its biologically inert chemical structure and strong hydrophobicity, are ameliorated considerably after the S-PIII treatment, which is more favorable for endothelial cell (EC) adherence, spreading, and proliferation. In particular, compared to a bare ePTFE surface, Ta-implanted ePTFE possesses an antithrombogenic property, suppressing platelet adhesion and activation on its surface. From an in vivo pilot study with a canine aortic bypass model, Ta-implanted ePTFE demonstrates substantially suppressed early thrombosis with rapid formation of EC monolayers covering the luminal surface.

Minitoracotomía anterior derecha: un abordaje consolidado

IntroductionThe right anterior mini-thoracotomy is an alternative approach to medial sternotomy to treat mitral pathology, tricuspid valve, and atrial septal defect. In addition to avoiding complications associated with sternotomy, this approach provides cosmetic advantages and early recovery. MethodsA retrospective observational study was performed on the entire series of 106 patients operated using a right anterior mini-thoracotomy between January 2013 and June 2019. In the first 55 cases the procedure was performed with direct vision, and from October 2017 the surgery was video-assisted. A comparison is made of the perioperative data of both groups. ResultsThe procedures performed were: 46 mitral repairs, 30 mitral replacements, 15 tricuspid replacements, and 15 atrial septal defect closures. Eighteen patients had previous cardiac surgery. The mean EuroSCORE I was 6.08. Hospital mortality was 0.9% (one patient). Conversion to sternotomy was performed in 6 patients. The mean aortic clamping time and bypass time was 88±27 and 137±36minutes, respectively. The mean hospital stay was 5.8±1.9 days. Only 22% of patients received a red blood cell transfusion. When the perioperative results of the first 55 patients were compared with the group in which video-assisted surgery was performed (51 patients), hospital stay and red blood cell transfusion improved significantly in the video-assisted group. ConclusionsThe right anterior mini-thoracotomy is a safe alternative to sternotomy with at least the same standards of quality and postoperative morbidity and mortality. The introduction of a thoracoscopic camera and experience, improved the initial results.

One-stage repair of aortic coarctation and cardiac pathology via sternotomy

Background Aortic coarctation is a hereditary disease often accompanied by ascending aortic aneurysm and aortic valve disease. We introduce a single-stage surgical treatment option for patients with aortic coarctation, ascending aortic aneurysm, and aortic valve disease, with a comparative analysis of the results. Methods The study included six patients with aortic coarctation, ascending aortic aneurysm, and aortic valve disease. All operations were performed by a full median sternotomy. For a comparative analysis, the patients were divided into two groups: 3 patients underwent ascending-to-descending aortic bypass, and the other 3 underwent surgical aortic coarctation repair. The short- and medium-term postoperative periods were monitored. The mean duration of monitoring was 27 months. Results When comparing the 2 groups, we observed a tendency for improvement in all intraoperative parameters in the 2nd group. There was no mortality in the postoperative hospital period. One (16.7%) patient died of stroke in the medium-term postoperative period. The other 5 patents showed no signs of procedure-related complications. Conclusion We recommend performing a single-stage procedure for surgical treatment of coarctation of the aorta with concomitant aneurysm of the ascending aorta and aortic valve disease. Compared to ascending-to-descending aortic bypass, surgical repair of aortic coarctation is more physiological, feasible via a sternotomy, and tends to improve intraoperative factors.

P5983Pre-operative physical performance as an independent predictor of in-hospital outcomes in older patients undergoing elective cardiac surgery

Abstract Introduction Risk stratification of patients candidate to cardiac surgery is usually based on the Society of Thoracic Surgeons (STS) score or on the Euroscore II. However, these risk scores has limited predictive value in elderly patients. Purpose We conducted a study to determine whether the Short Physical Performance Battery (SPPB), a tool assessing physical performance, predicts hospital death and major morbidity, beyond STS risk score. The outcome was a composite end-point as defined by STS Major Morbidity or Operative Mortality (STS-MM) in STS Risk Model Outcomes: operative mortality, stroke, renal failure, prolonged mechanical ventilation, deep sternal wound infection, and reoperation. Methods In this prospective, single-center, cohort, hospital-based study, conducted at Careggi University Hospital, Florence, Italy, all patients aged 75+ years referred for an elective coronary aortic by-pass grafting, valvular surgery or combined cardiac surgery were evaluated pre-operatively. Assessment included SPPB, cognitive and functional status and evaluation of comorbidity. Patients receiving emergency/urgent cardiac surgery or a procedure not considered in the STS risk score calculator, who reported previous cardiac surgery or were clinically unstable were excluded. Participants were classified according to the STS-Predicted Risk Of Mortality (STS-PROM) as at low (&lt;4%), intermediate (4 to 8%) or high risk (&gt;8%). Results Out of 250 participants (females: 48.4%; mean age: 79.9 years), 148 (59.2%) were at low, 73 (29.2%) at intermediate and 29 (11.6%) at high risk, based on the STS-PROM. Mean±SEM SPPB score was 8.8±0.2, 7.1±0.4 and 6.0±0.7 in participants at low, intermediate, and high risk, respectively (p&lt;0.001). The outcome occurred in 67 subjects (26.8%). SPPB score predicted the outcome in the entire study sample, controlling for STS-MM score, CKD, and anaemia (adjusted OR: 0.89, 95% CI 0.81–0.98 per each point increase; p 0.017). When analyses were repeated separately in participants with STS-PROM indicative of low (&lt;4%) and in those at medium-high risk, the predictive value of SPPB was enhanced in the formers (adjusted OR 0.73, 95% CI 0.62–0.86 per each point increase; p&lt;0.001- controlling for STS score), whereas was lost in the latter. An alternative model was subsequently tested, where STS score was not included and peripheral artery disease and creatinine (variables contributing to the STS score) were individually entered: SPPB was confirmed as a significant predictor also in this model, controlling for anaemia, peripheral artery disease, and creatinine. The corresponding AUC was 0.813 (Figure 1). Figure 1 Conclusions SPPB predicts mortality and major morbidity in older patients undergoing elective cardiac surgery, in particular in those classified as low-risk with the STS risk score. Use of SPPB should therefore be recommended to improve preoperative risk stratification of older patients.

Home Care Nursing After Elective Vascular Surgery: An Opportunity to Reduce Emergency Department Visits and Hospital Readmission

Background Events occurring outside the hospital setting are underevaluated in surgical quality improvement initiatives and research. Objective To quantify regional variation in home care nursing following vascular surgery and explore its impact on emergency department (ED) visits and hospital readmission. Methods Patients who underwent elective vascular surgery and were discharged directly home were identified from population-based administrative databases for the province of Ontario, Canada, 2006–2015. The index surgeries included carotid endarterectomy, open and endovascular aortic aneurysm repair and bypass for lower extremity peripheral arterial disease. Home care nursing within 30 days of discharge was captured and compared across regions. Using multilevel logistic regression, we characterised the association between home care nursing and the risk of an ED visit or hospital readmission within 30 days of discharge. Results The cohort included 23 617 patients, of whom 9002 (38%) received home care nursing within 30 days of discharge home. Receipt of nursing care after discharge home varied widely across Ontario’s 14 administrative health regions (range 16%–84%), even after accounting for differences in patient case mix. A lower likelihood of an ED visit or hospital readmission within 30 days of discharge was observed among patients who received home care nursing following three of four index surgeries: carotid endarterectomy OR 0.74, 95% CI 0.61 to 0.91; endovascular aortic aneurysm repair OR 0.85, 95% CI 0.72 to 0.99; open aortic aneurysm repair OR 1.06, 95% CI 0.91 to 1.23; bypass for lower extremity peripheral arterial disease OR 0.81, 95% CI 0.72 to 0.92. Conclusion Home care nursing may contribute to reducing ED visits and hospital readmission and is variably prescribed after vascular surgery.

PSP-like syndrome after aortic surgery in adults (Mokri syndrome).

A rare progressive supranuclear palsy-like syndrome seemingly triggered by aortic surgery was first described in 2004. This largest case series to date describes the features of this syndrome. We searched the Mayo Clinic electronic medical records using the advanced cohort explorer search engine for patients evaluated for neurologic symptoms after cardiac-aortic surgery in the past 30 years. Data were extracted to Microsoft Excel from the identified patients and included clinical and neuroimaging features and outcomes. Twenty-five patients met the inclusion criteria. All surgeries were performed under thoracic aortic bypass and deep hypothermia. Surgery included aortic aneurysm, aortic valve repair, and/or aortic dissection repair. Surgical records were unavailable, although surgery was documented in the Mayo record as uncomplicated in 60% of cases. In the remaining cases, no particular intraoperative or postoperative complications were documented at a high frequency. A typical triad was documented: supranuclear gaze palsy (SNGP; 100%), gait imbalance (80%), and dysarthria (96%). Part or all of the triad was observed before hospital discharge and stabilized over the course of days-weeks. A second phase of symptom worsening plus new symptoms developed up to a year later; this decline continued for up to several years before stabilization. Delayed epileptic seizures occurred in 32% of patients. Brain MRI revealed only nonspecific findings. This syndrome following adult thoracic aortic bypass surgery with deep hypothermia remains unexplained. It follows a biphasic course and is characterized by the triad of SNGP, unsteady gait, and a predominantly ataxic dysarthria.

Surgical management of renovascular hypertension in children and young adults: a 13-year experience.

In this study, we aimed to evaluate the early and mid-term outcomes of surgery for renovascular hypertension (RVH) at our institution, within the last 13 years. We retrospectively reviewed 19 patients who underwent surgery for RVH, between 2005 and 2017. The age at operation, clinical characteristics, cause of arterial stenosis, diagnostic workup, surgical management and outcomes during the follow-up were analysed. The continuous variables were expressed as mean ± standard deviation. Twelve female and 7 male patients underwent surgery for RVH. Their mean age was 17.07 ± 11.9 years (range 4-42 years). Nine patients had renal arterial stenosis, and 10 patients had midaortic syndrome (MAS). Aortorenal bypass with the saphenous vein was performed in 6 patients with renal arterial stenosis and 1 patient with MAS. An isolated thoracic aorta-abdominal aortic bypass was performed in 1 patient with MAS, and thoracic aorta-abdominal aortic bypass combined with unilateral aortarenal bypass was performed in 9 patients with MAS. The other surgical procedures performed were 2 autotransplantations and 2 unilateral nephrectomies. Among the patients with MAS, 4 underwent reoperation. The mean follow-up duration was 45.58 ± 32.7 months. Hypertension was cured in 3 patients and improved in 14 patients. The postoperative follow-up creatinine levels were similar to preoperative creatinine levels. All bypasses were patent on mid-term follow-up. One patient who underwent aortorenal bypass died 14 months postoperatively. Surgical management is a suitable option for patients with RVH, who were unresponsive to medical and/or endovascular management. Surgical methods are safe and effective in children and young adults with RVH.

Surgical repair of cervical aortic arch: An alternative classification scheme based on experience in 35 patients

ObjectiveCervical aortic arch (CAA) is rare and difficult to repair. Clinical experience is limited. We report the surgical techniques and midterm outcomes in 35 patients with CAA based on an alternative classification scheme. MethodsOf 35 patients with CAA, 30 (85.7%) had left-sided aortic arch and 5 had (14.3%) right-sided aortic arch (all 5 had a vascular ring). Mean age was 34.2 ± 13.1 years, 23 were female (65.7%), and 18 were asymptomatic (51.4%). Surgical access and procedure were chosen according to an alternative classification scheme that is based on the presence or absence of vascular ring and relationship of descending aorta to the side of the aortic arch. In the left-sided aortic arch group, aortic arch reconstruction though median sternotomy was performed in 15 patients, and distal arch and descending thoracic aortic replacement via left thoracotomy in 15 patients. In the right-sided aortic arch group, ascending-to-descending aortic bypass was done via median sternotomy in 2 patients and right thoracotomy in 1, and distal arch and descending thoracic aortic replacement via right thoracotomy in 2 patients. ResultsNeither death nor spinal cord injury occurred. Left recurrent laryngeal nerve injury, prolonged ventilation, and reexploration for bleeding occurred in 1 each. In 11 patients with coarctation, the upper-lower limb gradient decreased significantly postoperatively (from 34.0 ± 12.7 to 10.2 ± 2.7 mm Hg; P < .01). The diseased aortic segment was excluded in 34 patients, except 1 with residual aneurysm in the proximal descending thoracic aorta. Follow-up was complete in 100% at mean 4.4 ± 2.0 years. No late death, limb ischemia, or stroke occurred. Endovascular repair was performed in 1 patient, and ascending aortic dilation occurred in 1 patient. The residual aorta remained nondilated in 33 patients. Aortic grafts were patent in 100%, with no anastomotic leak or pseudoaneurysm. At 6 years, the incidences of death, aortic events, and event-free survival were 0%, 6.5%, and 93.5%, respectively. ConclusionsOpen repair of CAA can achieve favorable early and midterm outcomes. Surgical accesses and procedures should be chosen based on type of CAA, anatomic variations and associated anomalies. Our alternative categorization scheme of CAA is intuitive and comprehensive, which may facilitate classification and surgical decision making.

Computational analysis of renal artery flow characteristics by modeling aortoplasty and aortic bypass interventions for abdominal aortic coarctation

ObjectiveSuprarenal abdominal aortic coarctation (SAAC) alters flow and pressure patterns to the kidneys and is often associated with severe angiotensin-mediated hypertension refractory to drug therapy. SAAC is most often treated by a thoracoabdominal bypass (TAB) or patch aortoplasty (PA). It is currently unclear what effect these interventions have on renal flow and pressure waveforms. This study, using retrospective data from a patient with SAAC subjected to a TAB, undertook computational modeling to analyze aortorenal blood flow preoperatively as well as postoperatively after a variety of TAB and PA interventions. MethodsPatient-specific anatomic models were constructed from preoperative computed tomography angiograms of a 9-year-old child with an isolated SAAC. Fluid-structure interaction (FSI) simulations of hemodynamics were performed to analyze preoperative renal flow and pressure waveforms. A parametric study was then performed to examine the hemodynamic impact of different bypass diameters and patch oversizing. ResultsPreoperative FSI results documented diastole-dominated renal perfusion with considerable high-frequency disturbances in blood flow and pressure. The postoperative TAB right and left kidney volumes increased by 58% and 79%, respectively, reflecting the increased renal artery blood flows calculated by the FSI analysis. Postoperative increases in systolic flow accompanied decreases in high-frequency disturbances, aortic pressure, and collateral flow after all surgical interventions. In general, lesser degrees of high-frequency disturbances followed PA interventions. High-frequency disturbances were eliminated with the 0% PA in contrast to the 30% and 50% PA oversizing and TAB interventions, in which these flow disturbances remained. ConclusionsBoth TAB and PA dramatically improved renal artery flow and pressure waveforms, although disturbed renal waveforms remained in many of the surgical scenarios. Importantly, only the 0% PA oversizing scenario eliminated all high-frequency disturbances, resulting in nearly normal aortorenal blood flow. The study also establishes the relevance of patient-specific computational modeling in planning interventions for the midaortic syndrome.

Surgical Renovascular Reconstruction for Renal Artery Stenosis and Aneurysm: Long-Term Durability and Survival

To study functional outcome, mortality, and dialysis free survival in patients undergoing open primary surgical repair of renal artery stenosis (RAS) or aneurysm (RAA). This was a retrospective single centre study of patients undergoing open surgical renal artery reconstruction from 1993 to 2007. Blood pressure, renal function, dialysis dependence, vessel patency, and mortality were registered. Survival was investigated by cross matching with the population registry, yielding up to 20 years of follow up. Of the 40 patients operated on, 25 (63%) were women. RAS was the indication for reconstruction in 31 patients; 23 had atherosclerotic aetiology (ARAS), and eight had fibromuscular dysplasia (FMD). Nine patients had RAA. Patients with ARAS were older (p = .008), had more extensive peripheral arterial disease (p = .004), and inferior renal function (p = .003) compared with patients with FMD or RAA. In FMD and RAA, the right renal artery was affected in 13/17 (76%) cases, whereas in ARAS the disease was evenly distributed. In patients with ARAS, 15/25 (60%) stenotic renal arteries (two bilateral procedures) were managed by aorto-renal bypass, and 2/25 (8%) through ilio-renal bypass. In 8/25 (32%) endarterectomy was performed. In FMD, all but one patient underwent aorto-renal bypass. Early mortality was 2.5% (one patient with ARAS). One patient with ARAS required dialysis post-operatively. Systolic blood pressure was significantly reduced in patients with ARAS, from 180 mmHg (median) pre-operatively to 155 mmHg at one month (p = .003) and 160 mmHg at one year (p = .03). Need for medication decreased from three or more drugs to two drugs at one month (p = .01). In FMD, there was a similar tendency. Three patients underwent re-intervention for restenosis: two endovascularly and one by open surgery. The overall 5 year survival was 88%. Median follow up was 10.6 years. Open surgical renal arterial reconstruction was performed with low mortality, fairly low morbidity, and excellent durability. Open surgery should still be considered a therapeutic option in complex renal artery disease.

Home care nursing after elective vascular surgery: an opportunity to reduce emergency department visits and hospital readmission

BackgroundEvents occurring outside the hospital setting are underevaluated in surgical quality improvement initiatives and research.ObjectiveTo quantify regional variation in home care nursing following vascular surgery and explore its impact on...

Cardiopulmonary bypass time is an independent risk factor for acute kidney injury in emergent thoracic aortic surgery: a retrospective cohort study

BackgroundThoracic aortic surgery and cardiopulmonary bypass are both associated with development of postoperative acute kidney injury. In this study, we undertook to investigate the relationship between cardiopulmonary bypass time and postoperative acute kidney injury in patients undergoing thoracic aortic surgery for acute DeBakey Type I aortic dissection.MethodsAll patients receiving thoracic aortic surgery for acute DeBakey Type I aortic dissection in Beijing Anzhen hospital from December 2015 to April 2017 were included. Cardiopulmonary bypass time was recorded during surgery. Acute kidney injury was defined based on the Kidney Disease Improving Global Outcomes criteria. A total of 115 consecutive patients were eventually analyzed.ResultsThe overall incidence of acute kidney injury was 53.0% (n = 61). The average age was 47.8 ± 10.7 years; 74.8% were male. Mean cardiopulmonary bypass time was 211 ± 56 min. In-hospital mortality was 7.8%. Multivariate logistic regression revealed that cardiopulmonary bypass time was independently associated with the occurrence of postoperative acute kidney injury after adjust confounding factors (odds ratio = 1.171; 95% confidence interval: 1.002–1.368; P = 0.047).ConclusionsCardiopulmonary bypass time is independently associated with an increased hazard of acute kidney injury after thoracic aortic surgery for acute DeBakey Type I aortic dissection. Further understanding of the mechanism of this association is crucial to the design of preventative strategies.