Traumatic aortic injury: does the anatomy of the aortic arch influence aortic trauma severity?

Purpose

Traumatic aortic injury (TAI) is a rare but life-threatening type of injury. We investigate whether the anatomy of the aortic arch influences the severity of aortic injury.

Methods

This is a retrospective study of twenty-two cases treated with TEVAR for TAI in our department from 2009 to 2014. Aortic injury was assessed in accordance with the recommendations of the Society of Vascular Surgery. We measured the aortic arch angle and the aortic arch index, based on the initial angio-CT scan, in each of the analyzed cases.

Results

The mean aortic arch index and mean aortic arch angle were 6.8 cm and 58.3°, respectively, in the type I injury group; 4.4 cm and 45.9° in the type III group; 3.3 cm and 37° in the type IV group. There were substantial differences in both the aortic arch index and the aortic arch angle of the type III and IV groups. A multivariate analysis confirmed that the aortic arch angle was significantly associated with the occurrence of type III damage (OR 1.5; 95% CI 1.03–2.2).

Conclusions

The severity of TAI is influenced by the sharpness of the aortic arch. There is an inverse relationship between the severity of aortic injury and the aortic arch index.

     

Thoracic endovascular aortic repair for retrograde type A aortic dissection

ObjectiveThe efficacy of thoracic endovascular aortic repair (TEVAR) for retrograde type A aortic dissection (r-TAAD) with the entry tear in the descending aorta has not been clarified.MethodsThe medical records of 31 patients who underwent TEVAR for r-TAAD at three institutions between May 1997 and January 2016 were retrospectively reviewed.ResultsThe mean age of the patients (30 men and 1 woman) was 64 ± 11 years. The entry tear was located in the descending thoracic aorta in all patients. Seven patients (23%) had dissection-related complications. The false lumen of the ascending aorta was patent in 13 patients (42%) and thrombosed in 18 (58%). The maximum diameter of the ascending aorta was 45 ± 4 mm. TEVAR was performed in the acute phase in 24 patients (77%) and in the subacute phase in 7 (23%). Only one patient (3%) died of aortic rupture within 30 days after TEVAR. Early aorta-related adverse events were observed in eight patients (26%), of whom five underwent additional interventions. The mean follow-up period was 99 ± 69 months. There were no late aorta-related deaths, although five patients died of other causes during follow-up. Overall survival rates at 1 year, 5 years, and 10 years were 97%, 93%, and 80%, respectively. Late aorta-related adverse events were observed in seven patients (23%), of whom five underwent additional interventions. Aorta-related event-free survival rates at 1 year, 5 years, and 10 years were 58%, 58%, and 51%, respectively.ConclusionsTEVAR for r-TAAD seems promising in terms of survival. However, the incidence of postoperative aorta-related adverse events is not negligible, so careful selection of patients is important. In addition, close follow-up is mandatory after TEVAR to avoid catastrophic consequences.     

Are bicuspid aortic valves a limitation for aortic valve repair?

Objective: To compare the mid-term results after aortic valve (AV) repair in bicuspid AVs with those in tricuspid AVs. Methods: Between 2000 and 2010, 100 patients (mean age 47.2 years) underwent AV repair procedures for insufficient bicuspid AV (n = 43) and tricuspid AV (n = 57). Aortic regurgitation (AR) more than moderate was present in 31/43 and 21/57 patients in the bicuspid AV and the tricuspid AV group, respectively. Concomitant root replacement by either the reimplantation or the remodeling technique was performed in 42 patients (bicuspid AV 17/43, tricuspid AV 25/57). All patients were prospectively studied with postoperative and further annual clinical assessment and echocardiography. Follow-up was 99% complete with a mean follow-up time of 22 months. Results: Three patients died during the initial hospitalization, all due to postoperative cardiac failure. Overall actuarial 3 years’ survival was 93 ± 4.2% without significant differences between the two groups. Overall actuarial 3 years’ freedom from AV-related reoperation was 86 ± 5.1% without significant differences between the groups (85 ± 9.7% for bicuspid AV, 86 ± 6.0% for tricuspid AV; log-rank test: p = 0.98). Overall actuarial 3 years’ freedom from recurrent AR ≥ moderate was 100% and AR > trace was 71.3 ± 8.2% without significant differences between the groups (76.5 ± 11.7% for bicuspid AV, 71.4 ± 9.4 for tricuspid AV; log-rank test: p = 0.97). Conclusions: The mid-term outcome in terms of survival, freedom from reoperation or recurrent AR is similar for both groups of patients after AV repair procedures. Therefore, we advocate valve repair also in patients presenting with an insufficient bicuspid AV.     

Is aortic angiography necessary for accurate planning of endovascular aortic aneurysm stents?

Endovascular management of abdominal aortic aneurysms (AAA) relies upon accurate stent design. We hypothesized the length of the stent could be measured from computed tomogram (CT) generated 3D surface rendered images of the abdominal vessels, eliminating the need for digital subtraction angiography (DSA). METHODS: The CT scans from a consecutive series of 54 patients considered for endovascular AAA repair were reviewed. A TRIFAB Zenith (Cook) endovascular aortic stent was designed, using the manufacturer's sizing computer program. These hypothetical stents were compared to those that had been implanted, using measurements from both angiogram and CT (Spearman's test of correlation (p<0.05)). RESULTS: The stent body size and short limb extension (SLE) of stents in each group was similar (correlation coefficient 0.70(p<0.01) and 0.50 (p=0.014)), however, CT alone significantly underestimated the length of the long limb extension (LLE) (correlation coefficient 0.095). CONCLUSION: These data suggest that CT underestimates the tortuosity of iliac vessels. Aortic angiography is necessary for accurate AAA endovascular stent design.     

Optimal timing of aortic valve replacement for aortic stenosis--are we operating late?

OBJECTIVE: To evaluate the adherence to current guidelines for surgery in patients with aortic valve stenosis. DESIGN: From 1 January 1997 to 31 May 1999, 99 patients were accepted for aortic valve surgery with preserved left ventricular function and normal coronary angiogram. On admission for operation, 20 patients were evaluated regarding symptoms, exercise capacity, and left ventricular morphology and function. RESULTS: There were 14 men and 6 women, mean age 64.3 years. Years from symptom onset varied from 2.1 to 3.2. Dyspnoea was the most common limiting symptom. Thirty per cent of the patients were classified as NYHA IIIB. Physical capacity was reduced to 79% of the expected. Left ventricular hypertrophy was present in 14/20 patients. Left ventricular systolic function was reduced with mean ejection fraction of 0.46. Diastolic dysfunction (E/A ratio <1) was present in 12 patients. CONCLUSION: Many patients accepted for aortic valve replacement due to aortic stenosis show advanced disease and are referred for surgery later in the disease process than is recommended in the current guidelines.     

Is aortic valve-sparing operation or replacement with a composite graft the best option for aortic root and ascending aortic aneurysm?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether it is better to preserve the aortic valve in patients with aortic root or ascending aortic aneurysms. Altogether 380 papers were found using the reported search, of which 23 represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. All the studies identified are retrospective. Sixteen papers reported a 10-year reoperative-free survival from 54% to 98% for valve-sparing operations and 67-81% for replacement operations in two further studies. Six papers reported their 10-year freedom from re-operation as 75-97% for valve-sparing operations. Our findings suggest that the results of both techniques are excellent and comparable, and the operating surgeon may safely make his decision as to which technique to select based on patient factors and his own experience without compromising the long-term outcomes of the patient.     

Valve-sparing aortic root replacement in bicuspid aortic valves: a reasonable option?

OBJECTIVES: Aortic dilatation occurs in many patients with bicuspid aortic valves. We have added root replacement using the remodeling technique originally designed for tricuspid aortic valves to bicuspid aortic valve repair for treatment of the dilated root. We compared the results of remodeling in bicuspid aortic valves with those in tricuspid aortic valves. METHODS: From October 1995 through January 2004, 60 patients underwent root remodeling for bicuspid aortic valves (group A), and 130 patients underwent root remodeling for tricuspid aortic valves (group B). Correction of cusp prolapse was more often performed in group A (group A, 50/60; group B, 47/130; P < .0001). Transthoracic echocardiography was performed at 1 week, 6 and 12 months, and every year thereafter. Cumulative follow-up was 527 patient-years (mean, 2.9 +/- 2 years). RESULTS: No patient died in group A. Hospital mortality in group B was 5% (5/100; 95% confidence interval,1.6%-11.3%) after elective operations and 10% (3/30; 95% confidence interval, 2.1%-26.5%) after emergency operations. Mean systolic gradients were identical at 1 year (group A, 4.8 +/- 2.1 mm Hg; group B, 4.0 +/- 2 mm Hg) and 5 years (group A, 4.5 +/- 2.3 mm Hg; group B, 3.9 +/- 2.2 mm Hg). Freedom from aortic regurgitation of grade 2 or higher at 5 years was 96% in group A and 83% in group B ( P = .07), and freedom from reoperation at 5 years was 98% in group A and 98% in group B ( P = .73). CONCLUSIONS: Valve-sparing aortic replacement with root remodeling can be applied to aortic dilatation and a regurgitant bicuspid aortic valve. Hemodynamic function and valve stability of a repaired bicuspid aortic valve are comparable with those seen in cases of tricuspid anatomy.     

Is a stentless aortic valve superior to conventional bioprosthetic valves for aortic valve replacement?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether a stentless valve is superior to conventional stented valves when tissue aortic valve replacement is performed. Altogether more than 515 papers were found using the reported search, of which 16 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that stentless valves allow a larger effective orifice area valve to be implanted with a lower mean and peak aortic gradient postoperatively. At six months several studies and a meta-analysis have shown superior left ventricular mass regression in the stentless valve groups. However, by 12 months the stented valve groups catch up in terms of mass regression and this significance disappears. So the 'eminent speaker from the floor', was right with his statement, that there have been no definitively proven benefits for stentless valves.     

Stapled aortic anastomoses: a minimally invasive, feasible alternative to videoscopic aortic suturing?

Widespread applications of totally laparoscopic aortic reconstructions have been limited by the long cross-clamp time required to suture the aortic anastomosis despite improvement in instrumentation. The authors' hypothesis was that a "one-step anastomosis concept" using an intraluminal stapler would allow shorter cross-clamp time but similar patency and imperviousness as videoscopic suturing techniques. An intraluminal stapler (Endopath-ILS, Ethicon) with a modified anvil was used to perform videoscopic-assisted thoracic aorta-to-iliac artery bypass with a 21 mm by 8 mm polytetrafluoroethylene (PTFE) graft in 22 sheep through a minimally invasive approach using a 5 cm thoracotomy. The graft-to-iliac artery anastomoses were hand sutured through a flank incision. Twelve sheep were used to establish the technique and 10 subsequent animals constituted the study group. Aortic cross-clamp time, imperviousness, and need for additional sutures were recorded and compared to previously reported data using videoscopic suturing in pigs. Patency was assessed by comparing lower limb arterial pressures. Macroscopic and microscopic examinations of the anastomoses were performed at different time-points within the first 3 months. Videoscopic-assisted stapled anastomoses were also performed on atherosclerotic aortas of 3 human cadavers. Stapled anastomoses between the thoracic aorta and PTFE graft were completed in 8 of 10 animals. Two animals were euthanized after stapler failure and anastomotic bleeding. Sutures to strengthen the anastomosis had to be used in 4 cases. Mean aortic cross-clamp time in 8 successful cases was 4.3 +/-2.9 minutes (range 2-11 minutes) and was significantly shorter than clamp time of videoscopic suturing technique (48.7 +/-9.4 minutes, p < 0.0001). Imperviousness was good or excellent in 4 animals and fair in 4 animals. All anastomoses were patent at the end of the procedure. Examination of the anastomosis of the 2 failed interventions showed medial aortic tear surrounding the anastomosis in 1 case and misfired staples in the other. No graft occlusion was noted during follow-up ranging from 0 to 12 weeks. At the time of harvest, no bleeding was noted after epinephrine and volume infusion to increase mean arterial pressure to 200 mm Hg for 15 minutes. Macroscopic examination of the anastomoses revealed adequate healing with circumferential stapling of the prosthesis to the aortic wall and no stenosis or thrombus except in 1 false aneurysm (1/7, 14%). Surface electron microscopy showed cells coverage of the anastomosis surface. When applied on human cadaver thoracic and abdominal aorta with atherosclerotic changes, clamping times of less than 5 minutes were achieved. However, imperviousness tested with saline was poor. An automatic stapling device allows performance of a graft-to-aorta anastomosis through a minimally invasive approach with shorter clamping time than a videoscopic suturing technique. However, the current technique of aortic stapling is unreliable and further improvements are needed.     

Progression of aortic valve stenosis: TGF-β1 is present in calcified aortic valve cusps and promotes aortic valve interstitial cell calcification via apoptosis

Background

Aortic valve stenosis characteristically progresses due to cuspal calcification, often necessitating valve replacement surgery. The present study investigated the hypothesis that TGF-β1, a cytokine that causes calcification of vascular smooth muscle cells in culture, initiates apoptosis of valvular interstitial cells as a mechanistic event in cuspal calcification.

Methods

Noncalcified and calcified human aortic valve cusps were obtained at autopsy or at the time of cardiac surgery. The distributions within cusps of TGF-β1, latent-TGF-β1-associated peptide, and TGF-β receptors were studied using immunohistochemistry. The effects of TGF-β1 on mechanistic events contributing to aortic valve calcification were also investigated using sheep aortic valve interstitial cell (SAVIC) cultures.

Results

Immunohistochemistry studies revealed that calcific aortic stenosis cusps characteristically contained within the extracellular matrix qualitatively higher levels of TGF-β1 than noncalcified cusps. Noncalcified normal valves demonstrated only focal intracellular TGF-β1. Addition of TGF-β1 to SAVIC cultures led to a cascade of events, including: cellular migration, aggregation, formation of apoptotic-alkaline phosphatase enriched nodules, and calcification of these nodules. The time course of these events in the SAVIC culture system was rapid with nodule formation with apoptosis by 72 hours, and calcification after 7 days. Furthermore, ZVAD-FMK, an antiapoptosis agent (caspase inhibitor), significantly inhibited calcification and apoptosis induced by TGF-β1, but had no effect on nodule formation. However, cytochalasin D, an actin-depolymerizing agent, inhibited nodule formation, but not calcification.

Conclusions

TGF-β1 is characteristically present within calcific aortic stenosis cusps, and mediates the calcification of aortic valve interstitial cells in culture through mechanisms involving apoptosis.     

Is preoperative balloon aortic valvuloplasty of interest for severe aortic stenosis in hip fracture surgery?

PurposeIn elderly patients, the discovery and management of a severe aortic stenosis (AS) prior to emergency non-cardiac surgery is a frequent and controversial issue. The objective of this study was to evaluate preoperative balloon aortic valvuloplasty (BAV) for severe AS in hip fracture surgery.MethodsWe conducted an observational, monocentric, retrospective study from 2011 to 2018. Survival (30-day, 90-day and 180-day mortality) and the occurrence of perioperative complications were analyzed and compared between control (i.e. no BAV prior to surgery) and preoperative BAV groups in patients with hip fracture surgery and a formal transthoracic echocardiographic diagnosis of severe AS (aortic valve area < 1 cm²). Patients' allocation to the intervention and control groups was after a discussion between cardiologist, anesthesiologist and the surgeon.ResultsAmong the 8506 patients who underwent hip fracture surgery, 29 patients in the control group and 30 patients in the BAV group were finally included. Kaplan-Meier survival analysis demonstrated a significant decrease in mortality in the BAV group (p=0.014) despite an increase in median time to operation of about 48 hours (p<0.0001). Multivariate analysis (stepwise logistic regression) showed that postoperative delirium (OR [95%CI]: 17.5 [1.8-168]; p=0.013) and postoperative acute congestive heart failure (OR [95%CI]: 59.4 [5.0-711.1]; p=0.0013) were predictive factors of 30-day mortality with an area under ROC curve of 0.90 (95%CI: 0.80-0.97; p<0.0001).Conclusionspreoperative BAV for severe AS could reduce the mortality of hip fracture patients despite an increase in time to operation. This improved survival could be linked to the decrease in cardiologic and neurologic adverse events. A larger prospective randomized study is necessary before generalizing our results.     

Is preservation of the aortic valve different between acute and chronic type A aortic dissections?

OBJECTIVES: In repair of acute type A aortic dissection, the type of proximal repair of the ascending aorta has been of great interest; however, very few reports are available regarding this issue in chronic aortic dissection. The surgical strategies for proximal repair in chronic dissection may not the same as those for acute dissection. We reviewed our 10-year experience of both acute and chronic type A aortic dissections in order to elucidate the validity of valve preservation and the long-term results of aortic regurgitation (AR). METHODS: From 1990 to 1999, 93 patients (55 acute and 38 chronic dissections) underwent operation for type A aortic dissection. Five Marfan patients were included in each group. The degree of AR was evaluated by echocardiography before and after (at hospital discharge and late follow-up) operation. RESULTS: In acute type A aortic dissection (n=55), 16 patients had AR grade II or greater (29%), of whom seven had AR grade III (13%). In 29 patients, dissection was found below the sinotubular junction (STJ) and 14 patients had AR grade II or greater (48%). The aortic valve was replaced in four patients (7%), of whom three had Marfan's syndrome. Only one non-Marfan patient required aortic valve replacement because of valve stenosis. In those whose aortic valve was preserved (n=51), three patients still had AR grade II at hospital discharge, while at late follow-up, AR had deteriorated to grade III in two of them, although no reoperation has been required so far. In chronic type A aortic dissection (n=38), 14 patients had AR grade II or greater (37%), of whom 11 had AR grade III or greater (29% vs. 13% in acute dissection; P=0.051). In 15 patients, dissection was found below the STJ and 12 patients had AR grade II or greater (80% vs. 48% in acute dissection; P=0.043). The aortic valve was replaced in eight patients (21% vs. 7% in acute dissection; P=0.051), including three Marfan patients. Of those whose aortic valve was preserved (n=30), two patients required reoperation for severe AR. The freedom from postoperative AR grade III or greater was 89% at 5 years for operative survivors with acute dissection and 92% for those with chronic dissection, respectively. CONCLUSIONS: This retrospective study suggests that preservation of the aortic valve in acute type A aortic dissection is feasible in non-Marfan patients regardless of the degree of AR. In chronic dissection, aortic root replacement needs to be considered when the degree of AR is greater than moderate because of a dilated STJ and/or annulus. In both acute and chronic dissections, satisfactory mid- to long-term results with a low incidence of reoperation were obtained in those whose aortic valve was preserved.