The effect of false lumen procedures during thoracic endovascular aortic repair in patients with chronic DeBakey type IIIB dissections.

OBJECTIVE: Although thoracic endovascular aortic repair (TEVAR) is commonly used for chronic DeBakey type IIIB (CDIIIB) dissections, aortic remodeling outcomes after the procedure have been unsatisfactory. Persistent retrograde flow to the false lumen (FL) through re-entry tears commonly causes treatment failure. The aim of this study was to clarify the safety and effect of the FL procedure (FLP) for aortic remodeling in patients with CDIIIB dissections. METHODS: From 2012 to 2016, there were 73 patients who underwent TEVAR for CDIIIB dissections. The surgery, accompanied by the FLP, was performed in 41 patients (group A, 56%); 32 patients (group B, 44%) underwent TEVAR alone. The FLP was defined as blocking the retrograde FL flow with commercial materials. Outcomes included whole thoracic aorta FL thrombosis and diameter change in the true lumen and FL. Diameters were measured at three levels (left subclavian artery, pulmonary artery bifurcation, and celiac axis). RESULTS: No in-hospital mortality was observed. There was one case each of paraplegia and stroke postoperatively. The whole thoracic aorta FL thrombosis rate was significantly higher in group A (83% vs 56%; P = .002). Significant aortic remodeling (true lumen expansion and FL regression) was observed in both groups. In multivariable Cox regression analysis, the FLP and the number of re-entries were independent predictors for thoracic FL thrombosis (hazard ratio, 2.339 [P = .009] and 0.709 [P < .001], respectively). CONCLUSIONS: Full-coverage TEVAR with the FLP seems to be a safe endovascular treatment and promotes thoracic FL thrombosis for patients with CDIIIB dissections.

One-year outcomes of total arch replacement and frozen elephant trunk using the E-vita Open NEO.

OBJECTIVES: In this cohort study, we aimed to assess the 1-year clinical outcomes of using the E-vita Open NEO™ hybrid prosthesis for total arch replacement with frozen elephant trunk (FET) to repair extensive aortic pathologies. METHODS: We reviewed individuals who underwent thoracic aortic surgery between April 2021 and March 2023 from the Gangnam Severance Aortic Registry. Exclusion criteria included ascending aortic replacement, 1 or 2 partial arch replacement, descending aortic replacement and total arch replacement without an FET. Finally, all consecutive patients who underwent total arch replacement and FET with E-vita Open NEO for aortic arch pathologies between April 2021 and March 2023 were included in this cohort study. The patients were divided into 3 groups based on their pathology: acute aortic dissection, chronic aortic dissection and thoracic aortic aneurysm. The primary end point was in-hospital mortality. The secondary end points during the postoperative period comprised stroke, spinal cord injury and redo sternotomy for bleeding. Additionally, the secondary end points during the follow-up period included the 1-year survival rate, 1-year freedom from all aortic procedures and 1-year freedom from unplanned aortic interventions. RESULTS: The study included 167 patients in total: 92 patients (55.1%) with acute aortic dissection, 20 patients (12.0%) with chronic aortic dissection and 55 patients (32.9%) with thoracic aortic aneurysm. The in-hospital mortality was 1.8% (n = 3). Strokes occurred in 1.8% (n = 3) of the patients, spinal cord injury in 1.8% (n = 3) and redo sternotomy for bleeding was performed in 3.0% (n = 5). There were no significant differences between the pathological groups. The median follow-up period (quartile 1-quartile 3) was 198 (37-373) days, with 1-year survival rates of 95.9%. At 1 year, the freedom from all aortic procedures and unplanned aortic interventions were 90.3% and 92.0%, respectively. CONCLUSIONS: The 1-year clinical outcomes of total arch replacement with FET using the E-vita Open NEO were favourable. Long-term follow-up is required to evaluate the durability of the FET.

Recent Surgical Outcomes of Congenital Heart Disease according to Korea Heart Foundation Data.

BACKGROUND AND OBJECTIVES: This study presents an update of the surgical outcomes of congenital heart disease (CHD) according to Korea Heart Foundation (KHF) data. METHODS: We investigated the data of the 7,305 patients who were economically supported by KHF in 2000-2014. Of them, we analyzed surgical outcomes of the 6,599 patients who underwent CHD surgery. RESULTS: The median patient age was 1.9 years (range, 0-71.5 years). Of the 6,599 patients, 5,616 (85.1%) underwent biventricular repair and 983 (14.9%) underwent palliative procedures. The mean Basic Aristotle Score was 6.6±2.2. A complex procedure (defined as Basic Aristotle Score above 6) was performed in 3,368 patients (51.0%). The early mortality rate was 3.8%, while the late mortality rate was 1.8%. Previous reports of the KHF (1984-1999) showed that the early surgical and late mortality rates were 8.6%, and 5.3%, respectively. There were 491 neonates (7.4%); among them, the early mortality rate was 12.2% and late mortality rate was 3.7%. There were 2,617 infants (40.0%); among them, the early mortality rate was 6.0% and the late mortality rate was 2.3%. A total of 591 patients from 30 countries were helped by the KHF. CONCLUSIONS: More neonatal surgeries (491 vs. 74 patients) were performed than those in the past (1984-1999). The surgical outcomes were much better than before. Our surgical outcomes revealed that the Republic of Korea has been transformed from a country receiving help to a country that helps other low socioeconomic status countries.

Temporal pattern of aortic remodelling after endovascular treatment for chronic DeBakey IIIb dissection.

OBJECTIVES: Endovascular treatment has emerged as a safe procedure for treating chronic DeBakey IIIb dissection. The objective of this study was to investigate the mid-term outcome and temporal pattern of aortic remodelling after endovascular treatment for DeBakey IIIb dissection. METHODS: From 2012 to 2017, 85 patients who underwent endovascular aortic repair for DeBakey IIIb dissection were enrolled. The temporal pattern of aortic remodelling in terms of false lumen (FL) thrombosis [level 1 (∼T7), level 2 (T7 ∼ coeliac axis) and level 3 (coeliac trunk ∼ aortic bifurcation)] and aortic diameter [mid-thoracic level (T7), coeliac axis and the largest infrarenal abdominal aorta] was investigated on serial follow-up computed tomography scan. RESULTS: Eighty-five patients underwent endovascular treatment during the study period. Male sex was a significant risk factor for repetitive reintervention and segments 2 and 3 FL thrombosis. The preoperative FL diameter at T7 was significantly associated with FL diameter regression. The number of visceral vessels from the FL and residual DeBakey IIIb dissection after type A repair were significant factors for FL growth at the coeliac trunk and at the largest infrarenal abdominal aorta. The overall mortality was 3 (3.6%). CONCLUSIONS: Endovascular treatment is a safe strategy in the management of DeBakey IIIb dissection. However, unfavourable aortic remodelling and repetitive reintervention were expected in male patients with a large number of visceral vessels from the FL and residual DeBakey IIIb dissection after type A repair. Endovascular treatment should be cautiously considered, and close follow-up is required for these patients.

Impact of Supraaortic Intimal Tears on Aortic Diameter Changes After Nontotal Arch Replacement.

BACKGROUND: This study evaluated the impact of the intimal tear location on aortic dilation and reintervention after nontotal arch replacement (non-TAR) for acute type I aortic dissection. METHODS: Between 2009 and 2017, 92 patients who underwent non-TAR for acute type I aortic dissection were enrolled. Intimal tears were analyzed at the supraaortic (SA) segment; segment 1, proximal descending thoracic aorta (DTA); segment 2, distal DTA; and segment 3, abdominal aorta. Aortic diameter was measured at the pulmonary artery bifurcation, celiac axis, maximal abdominal aorta, and maximal thoracoabdominal aorta using serial follow-up computed tomographic scans. The Fisher exact or χ2 test, independent t or Mann-Whitney U test, and log-rank test were used in the statistical analyses. RESULTS: The significant factors for increasing aortic diameter were the first location of intimal tear in the SA segment and segments 1 and 2. In the adjusted analysis, the first location of intimal tear in the SA segment and segment 1 was statistically significant. In the additional adjusted analysis, a segment 1 tear without SA tear was the only significant factor for increasing aortic diameter. The 5-year freedom from reintervention rate was significantly higher in patients with no intimal tear than in those with a segment 1 intimal tear with/without SA tear. CONCLUSIONS: We confirmed that SA and proximal DTA intimal tears are associated with subsequent aortic dilation and reintervention. These proximal aortic intimal tears might warrant aggressive surgical treatment at the initial operation or close postoperative follow-up.

Differential impact of intimal tear location on aortic dilation and reintervention in acute type I aortic dissection after total arch replacement.

OBJECTIVE: The study objective was to evaluate the differential impact of intimal tear location on aortic dilation and reintervention after total arch replacement for acute type I aortic dissection. METHODS: From 2009 to 2016, 85 patients underwent total arch replacement for acute type I aortic dissection with residual dissected thoracoabdominal aorta. Forty patients (47%) underwent serial computed tomography scans that were sufficient for analysis. Among these, 14 (35%) underwent total arch replacement via the frozen elephant trunk procedure. Intimal tears were analyzed (size and number) at 3 different levels (level 1, proximal descending thoracic aorta; level 2, distal descending thoracic aorta; level 3, abdominal aorta). Aortic diameter was measured at 4 levels (pulmonary artery bifurcation, celiac axis, maximal abdominal aorta, and maximal thoracoabdominal aorta) using serial follow-up computed tomography scans. The linear mixed model for a repeated-measures random intercept and slope model was used. The rate of freedom from reintervention was analyzed. RESULTS: In the unadjusted analysis, initial diameter of pulmonary artery bifurcation level, number of intimal tears, presence of 3- or 5-mm intimal tears, and frozen elephant trunk were not significant factors for aortic dilation or shrinking. The significant factors for aortic dilation were intimal tear location and number of visceral branches from the false lumen. The 3-year freedom from reintervention rate was significantly higher in patients with intimal tears 3 mm or greater at level 3 than in those with tears at level 1 (94.1% vs 37.5%, log-rank, P < .001). CONCLUSIONS: Intimal tear in the proximal descending thoracic aorta is the most important factor for aortic dilation and reintervention in acute type I aortic dissection after total arch replacement.

Locational impact of luminal communication on aortic diameter changes and reintervention in acute type I aortic dissection.

OBJECTIVES: The aim of this study is to evaluate the locational impact of a luminal communication on aortic diameter changes and reintervention after surgical repair of acute type I aortic dissection. METHODS: Between 2009 and 2017, 304 patients underwent operation for acute type I aortic dissection. Among them, 93 patients were enrolled. The luminal communications were analysed in segment 1 (the proximal descending thoracic aorta), segment 2 (the distal descending thoracic aorta) and segment 3 (the abdominal aorta). The aortic diameter was measured at the pulmonary artery bifurcation, coeliac axis, maximal abdominal aorta and maximal thoraco-abdominal aorta using serial follow-up computed tomography scans. The linear mixed model was used, and the rate of freedom from reintervention was analysed. RESULTS: In the adjusted analysis, the initial diameter of the maximal abdominal aorta and the first luminal communication in segment 1 was statistically significant. However, the slope value of the maximal abdominal aorta was smaller than that of the first luminal communication in segment 1 (0.024 vs 0.198). The 3-year freedom from reintervention rate was significantly higher in patients without a luminal communication than in those with an initial luminal communication in segment 1 (96% vs 47%, log rank, P = 0.003). CONCLUSIONS: A luminal communication at the proximal descending thoracic aorta (segment 1) is a significant factor for an increasing aortic diameter and reintervention after surgical repair of acute type I aortic dissection.

Complete Thoracic Aorta Remodeling After Endovascular Aortic Repair: A New Therapeutic Goal for Chronic DeBakey IIIb Aneurysms.

To introduce complete thoracic aorta remodeling as a new therapeutic target of thoracic endovascular aortic repair for chronic DeBakey IIIb aneurysms, and analyze the predictors for complete thoracic aorta remodeling. From 2012 to 2017, 75 patients underwent thoracic endovascular aortic repair for chronic DeBakey IIIb aneurysms. Complete thoracic aorta remodeling was defined as thoracic false lumen thrombosis with false lumen diameter <5 mm down to T-10 level. Major adverse aortic events were defined as aortic-related mortality, open conversion, and false lumen recanalization after thoracic false lumen thrombosis. Of the 75 patients included in this study, 60 (80.0%) demonstrated thoracic false lumen thrombosis; among them, overall mortality, open conversion, or false lumen recanalization after thoracic false lumen thrombosis occurred in two (3.3%), one (1.7%), and five (8.3%) patients, respectively. Nineteen (25.3%) of 75 patients who demonstrated complete thoracic aorta remodeling had no major adverse aortic events during follow-up. The number of visceral branches from the false lumen and residual intima tears were significant risk factors for complete thoracic aorta remodeling (HR 0.627, p = 0.041 and HR 0.754, p = 0.042). In chronic DeBakey IIIb aneurysms, complete thoracic aorta remodeling may be the ideal target for endovascular treatment rather than false lumen thrombosis. Additional procedures to eliminate the obstacles to complete thoracic aorta remodeling (number of visceral branches from the false lumen and residual intimal tears) and close follow-up after thoracic false lumen thrombosis may be needed to achieve the optimal outcome.

Outcomes of Stentless Thoracic Endovascular Aortic Repair for Chronic DeBakey IIIb Aneurysms.

BACKGROUND: We introduce a new endovascular procedure for favorable aortic remodeling in patients with chronic DeBakey IIIb (CDIIIb) aneurysms and present outcomes. METHODS: This study included 19 patients who underwent stentless thoracic endovascular aortic repair (TEVAR) for CDIIIb aneurysms between 2014 and 2016. Stentless TEVAR is defined as an endovascular procedure involving closure of communicating channels or obliteration of the false lumen itself using various materials. Thoracic false lumen thrombosis was defined as there was no flow in the false lumen of the thoracic aorta. Aortic diameter was measured at 3 levels (left subclavian artery, pulmonary artery bifurcation, and celiac axis). RESULTS: Fifteen of 19 (78.9%) patients demonstrated thoracic false lumen thrombosis. There was no mortality, and the mean follow-up duration was 16.8 months. False and true lumen diameters at the left subclavian and pulmonary artery levels significantly changed after the procedure (false lumen: 22.6 ± 16.6 versus 16.1 ± 14.4 mm, 23.2 ± 14.6 versus 18.0 ± 13.2 mm, p = 0.001 and p = 0.002, respectively; true lumen: 22.7 ± 8.7 versus 27.9 ± 6.3 mm, 19.0 ± 8.3 versus 24.3 ± 6.7 mm, p = 0.001 and p = 0.001, respectively). The number of visceral stent grafts and preoperative true lumen diameter at the pulmonary artery were independent predictors for thoracic false lumen thrombosis (hazard ratio, 3.445, 95% confidence interval, 1.494 to 7.946; p = 0.004; and hazard ratio, 1.106; 95% confidence interval, 1.029 to 1.189; p = 0.006, respectively). CONCLUSIONS: Stentless TEVAR seems to be a safe procedure and enables favorable aortic remodeling. Thus, this technique can be useful in a selected group of patients with CDIIIb aneurysms.

Residual Arch Tears and Major Adverse Events After Acute DeBakey Type I Aortic Dissection Repair.

BACKGROUND: Tear-oriented surgical procedure is considered a standard treatment for acute DeBakey type I aortic dissection (AIAD). However, long-term surgical outcomes, including aortic growth and rate of major adverse aortic events (MAAEs), have yet to be clarified. METHODS: Of the 274 patients who underwent surgical repair for AIAD between 2009 and 2016, 105 patients with both predischarge and follow-up computed tomographic scans were enrolled. The surgical extent was determined by primary entry tear location. We measured aortic diameters (pulmonary artery bifurcation, maximum diameter of the descending thoracic aorta [maxDTA], and celiac axis) and compared MAAEs (aorta growth rate ≥ 5 mm/year or maxDTA ≥ 55 mm according to surgical extent). RESULTS: Twenty-nine patients underwent total arch replacement (TAR); 76 underwent non-TAR. In the non-TAR group, patients with or without residual tears in the arch vessels were classified as having complete arch repair (non-TAR-CAR, n = 52) or incomplete arch repair (non-TAR-IAR, n = 24). Considerable differences were found in the aortic growth rate between the TAR and non-TAR groups and the non-TAR-CAR and non-TAR-IAR groups. Freedom from MAAEs at 5 years was considerably higher in the non-TAR-CAR group than in the non-TAR-IAR group (84.5% versus 31.1%). However, no differences were observed in the aortic growth rate and freedom from MAAEs between the TAR and non-TAR-CAR groups. CONCLUSIONS: Classic tear-oriented surgical procedure is insufficient for optimal long-term surgical outcomes, mainly regarding aortic dilation. CAR without residual arch vessel tears leads to favorable aortic remodeling in the residual DTA and prevents MAAEs after AIAD repair.

Diffusion-weighted magnetic resonance imaging lesions after repair of acute type A aortic dissection: association with neurocognitive outcomes†‡.

OBJECTIVES: We sought to analyse the preoperative status of arch vessels by postoperative diffusion-weighted magnetic resonance imaging (DWI) as a potential surrogate marker for cerebral thromboembolism and its relationship to neurocognitive outcomes. METHODS: Preoperative computed tomography (CT) and postoperative DWI were available for 50 patients who received surgery for acute type A aortic dissection. Two radiologists evaluated CT and DWI scans. Mini-mental status examinations (MMSE) were performed on the same day with DWI. RESULTS: Mean age of participants was 57 ± 14 years. MMSE and DWI were performed 6 ± 3 days after surgery. New cerebral embolisms were evident in 35 of 50 patients (70%) and often occurred as multiple lesions (28/35, 80%; range 2-21). Among patients with multiple lesions, 23 (66%) were clinically silent. Pathological lesions at the origin of the arch vessels correlated with the number and volume of new DWI lesions (P < 0.05). Degree of neurocognitive dysfunction tested by MMSE was negatively associated with age (r = -0.48, P < 0.0001) and left-sided DWI lesion number and volume (r = -0.74, P < 0.0001; r = -0.707, P < 0.0001). CONCLUSIONS: DWI revealed new cerebral embolisms in 70% of patients following surgery for acute type A aortic dissection. Lesion number and volume significantly correlated with pathological status of arch vessels. MMSE was representative of left-sided lesions.

Histologic changes of pulmonary arteries in congenital heart disease with left-to-right shunt (part 1): correlated with preoperative pulmonary hemodynamics. Emphasizing the significance of pulmonary arterial concentration.

The hemodynamic findings related to the histologic changes in the small pulmonary arteries in congenital heart disease were analyzed with a left-to-right shunt. A lung biopsy was performed during the repair because of pulmonary arterial (PA) hypertension (mean PA pressure > or = 15 mmHg) in 38 patients. There were 13 patients whose age ranged from 2 years to 25 years old. A preoperative cardiac catheterization was performed to locate the site of the defect and to determine the preoperative hemodynamic findings. Among them, 29 patients had pulmonary vascular resistance (PVR) > 2.5 unit/m2. The lung biopsy specimens were investigated microscopically for the Heath- Edward grade, morphometric analysis of medial wall thickness (MWT) and the rate of the decrease in the pulmonary arteriolar concentration (PAC) obtained by the alvoelo-arterial ratio divided by patients' age. All patients were in the Heath-Edward grade I to III (29 patients in grade I). This grade correlated with the MWT, but did not correlate with a decrease in the PAC. The MWT and the rate of the decrease in the PAC did not accompany each other, but either one had the tendency dominate the pattern in individual patients. The MWT had a close correlation with the mean PA pressure and PVR, and an even closer correlation in patients with a high PVR and those older than 2 years of age. The rate of the decreased in the PAC showed a weak correlation with the shunt volume in patients over 2 years of age or with a large shunt. In the high flow group (PVR < 2.5 unit/m(2), Qp/Qs > 2.0, n=14) the MWT was significantly thinner and the rate of the decrease in the PAC was significantly higher than the high resistance group (PVR > 2.5 unit/m2, Qp/Qs2 < 2.0, n=13). The rate of the decrease in the PAC correlated with the patients' age, but the MWT did not. The lung biopsy results in patients who had both left-to-right shunts and pulmonary hypertension showed that the rate of the decrease in the PAC was weakly related to the shunt volume and the MWT was related to the PA pressure and PVR. Either an increased MWT or the rate of the decrease in the PAC tended to dominate. These phenomena were prominent in patients older than 2 in whom a wide range of individual variations were noted in the morphometric pattern. The medial hypertrophy and the rate of the decrease in the PAC may be induced by different stimuli or that medial hypertrophy may play a role in preventing PAC decrease.

Evaluation of the post-shunt status with electron beam computed tomography in cyanotic congenital heart disease.

The assessment of the accuracy of Electron Beam Computed Tomography (EBCT) for the follow-up of pulmonary vascular system after the shunt operation in cyanotic congenital heart diseases was purpose of the study. The study group consists of 16 consecutive patients with cyanotic congenital heart disease who had Blalock-Taussig (BT) shunt (n=7), bi- directional cavo-pulmonary shunt (BCPS, n=7) and unifocalization (n=2). EBT images were obtained on systolic phase under EKG gating and after intravenous administration of contrast agent. We evaluated the shunt patency, anatomy of intrapericardial pulmonary artery, parenchymal pulmonary vessels and background lung attenuation for the pulmonary blood flow, and the presence of systemic arterial and venous collaterals. Angiography (n=12) and echocardiography (n=16) were used as the gold standards. EBCT was consistent with angiogram in detecting the shunt patency and in depicting the anatomy of the intrapericardial pulmonary artery. Occlusion of the BT shunts was not detected in 2 patients by echocardiography. Diffuse or focally decreased pulmonary flow on EBCT in 8 patients was consistent with the pulmonary hemodynamics pattern revealed by cardiac catheterization. Uneven attenuation between lobes was related with multifocal supply of pulmonary flow or occlusion of lobar pulmonary arteries. Systemic collateral arteries were observed in 5 at the corresponding site of the decreased pulmonary flow. Systemic venous collaterals seen in all patients following BCPS were eventually draining to the inferior vena cava in 5 and to the left atrium in 2. EBCT provided accurate information of the pulmonary vascular system after shunt and has unique advantage over echocardiography in assessing patency of BT shunt or unifocalization tubes within the pleural space, the estimation of regional difference in pulmonary hemodynamics, and the detection of systemic collateral vessels. Therefore EBCT may provide useful information about the timing of definitive correction and the need for a second shunt or an interventional procedure prior to total repair.

Histologic changes of pulmonary arteries in congenital heart disease with left-to-right shunt (part 2): emphasis on the significance of pulmonary arterial concentration in the correlation with pulmonary hemodynamics after repair Ed-- the above is an alternative title for your consideration.

We performed this study to assess the correlation of residual pulmonary hypertension in the immediate postoperative period with that in the late follow-up period, to assess the histologic changes of pulmonary arteries (PA) at the time of repair for patients with congenital heart disease consisting of left-to-right shunt, and to clarify the role of lung biopsy in determining the operability and reversibility of pulmonary vascular changes. Lung biopsy was performed during repair in 38 patients, with a wide range of age, who had congenital left to right shunt and pulmonary hypertension. All were Heath-Edward grade III or less. Morphometric study included measurement of medial wall thickness (MWT) and decrease rate of pulmonary arterial concentration (PAC). Mean PA pressure in the immediate postoperative period was measured in all 38 patients. Follow-up cardiac catheterization was performed in 15 patients (average 3.8 years after repair). At operation, 5 patients of this late follow-up group were under 2 years of age and the other 10 were 2 or more. During catheterization, pulmonary hemodynamic reaction was observed both under room air inhalation and after inhalation of hypoxic gas FiO2 0.15. Mean PA pressure and pulmonary vascular resistance (PVR) in the immediate postoperative period had a significant correlation with PA pressure and PVR values before the operation, but not with morphometry, Heath-Edward grade, or with pulmonary hemodynamics in late follow-up. During the late follow-up study, 5 of the 15 patients had pulmonary hypertension (defined as mean PA pressure > or = 15 mmHg) under room air inhalation, and PA hypertension was induced in 4 additional patients after hypoxic gas inhalation. There was no incidence of PA pressure or PVR values registering above the preoperative level. The degree of PA hypertension showed a correlation with the rate of PAC decrease and also with patients' age-at-operation. Multiple regression analysis showed that both the rate of PAC decrease and the age-at-operation contributed significantly to the degree of PA hypertension. Some of the patients over age 2 had a decreased rate of PAC above the regression line, which none of the patients under age 2 experienced. In patients with Heath-Edward grade III or less, residual pulmonary hypertension in the immediate postoperative period was not correlated with histology, but in late follow-up, it was with PAC and the age-at-operation. Therefore, a decrease of PAC is assumed to be a totally or partially irreversible pulmonary vascular change depending on the patient's age-at-operation, while medial hypertrophy is thought to be a reversible pulmonary vascular change. Lung biopsy could play an important role in determining the reversibility of pulmonary vascular obstruction, particularly in patients older than 2 years. Ed- re highlights above: such hyphenation is optional, but if used then it should be applied consistently throughout the paper. As 3 of the 4 entries in the abstract use it, I have maintained it consistently below.

Characterization of the pulmonary circulation according to hemodynamic changes by computed tomography.

Increased or decreased pulmonary blood flow (PBF) and an increased pulmonary vascular resistance (PVR), represent common and important change in pulmonary hemodynamics. In this study, we constructed 3 hemodynamic models in 5 dogs, that is, an increased and a decreased PBF model, and an increased PVR model. A CT perfusion scan was performed in each hemodynamic model. Perfusion parameters including blood flow (BF), blood volume (BV), mean transit time (MTT), and maximal slope (MS) were calculated automatically by specialized software and analyzed for changes according to hemodynamic status. In terms of the normal state, blood flow was affected by gravity and dependent area showed higher BF and BV and lower MS and MTT than the non-dependent area. The decreased PBF model showed a significant increase in BF and MS (p=0.046, 0.005) but no significant change in BV (p > 0.05), and a slight elongation of MTT (p > 0.05) versus the normal state. The increased PBF model showed a slightly increased BV and a slightly decreased MTT (p > 0.05). The increased PVR model showed significant reduction in BF, BV, and MS (p < 0.000, 0.007, 0.000) and a slight increase in MTT, but without statistical significance (p > 0.05). However, it was noticeable that the distribution of MTT with respect to gravity in the normal lung was completely reversed in the increased PVR model. In conclusion, based on our understanding of perfusion characteristic in normal state, abnormal regional hemodynamic changes in the lung can be detected and evaluated. Predicting changes in pulmonary vascular resistance should be possible by a thorough analysis of CT perfusion parameters.

Prognostic factors for aorta remodeling after thoracic endovascular aortic repair of complicated chronic DeBakey IIIb aneurysms.

OBJECTIVES: The use of thoracic endovascular aortic repair (TEVAR) for chronic DeBakey III type b (CDIIIb) aneurysms is controversial. We analyzed the potential prognostic factors affecting aorta remodeling after this procedure. METHODS: A total of 20 patients with CDIIIb aneurysms underwent TEVAR, with full coverage of reentry tears at the descending thoracic aorta. The potential factors affecting false lumen (FL) remodeling were analyzed, including reentry tears (communicating channels visible on the computed tomography angiogram), large intimal tears below the stent graft (≥ 2 consecutive axial cuts on the computed tomography angiogram), visceral branches arising from the FL, and intercostal arteries (ICAs) arising from the FL. RESULTS: All the patients had uneventful in-hospital courses; 2 patients (10%) required reintervention during the follow-up period. Thirteen patients (65%) had complete thrombosis of the FL at stent graft segment. Compared with the complete thrombosis group, the partial thrombosis group had more reentry tears (1.8 vs 2.3, P = .48), large intimal tears (0.8 vs 1.7, P < .05), visceral branches arising from the FL (1.2 vs 2.3, P < .05), and ICAs arising from the FL (3.8 vs 5.1, P = .35). Reentry tears, visceral branches, and ICAs from the FL were significant negative prognostic factors for FL shrinkage (P < .05). CONCLUSIONS: Although reentry tears above the celiac trunk were fully covered, the visceral branches and ICAs from the FL and all communicating channels below the celiac trunk kept the FL pressurized and were unfavorable prognostic factors for aorta remodeling after TEVAR for CDIIIb aneurysms.

Effects of intermittent lower body perfusion on end-organ function during repair of acute DeBakey type I aortic dissection under moderate hypothermic circulatory arrest.

OBJECTIVES: To avoid deep hypothermia-related side effects, moderate hypothermic circulatory arrest (HCA) is commonly employed during aortic arch repair, thereby jeopardizing end-organ protection. We sought to analyse the effect of intermittent lower body perfusion (ILBP) on end-organ function during repair of acute DeBakey type I aortic dissection (AIAD). METHODS: Between May 2008 and May 2011, 107 patients underwent surgical repair for AIAD. All operations were performed with selective cerebral perfusion (SCP) under either moderate HCA only (n = 57) or moderate HCA with ILBP (n = 50). Adverse outcomes, including operative mortality, permanent neurological deficit, temporary neurological deficit, renal failure requiring dialysis and hepatic dysfunction, were compared between the two groups. RESULTS: The mean body temperature at the initiation of SCP was 28.7 ± 1.9 °C. Overall operative mortality occurred in 6 (5.6%) patients. The incidences of permanent neurological deficit and temporary neurological deficit were 1.9 and 4.7%, respectively. None of the 9 (8.4%) patients who suffered postoperative renal failure requiring dialysis received ILBP. The laboratory data showed significantly lower levels of hepatic and kidney enzymes in the ILBP group (P < 0.05). CONCLUSIONS: Significantly lower levels of hepatic and kidney enzymes indicate more effective end-organ protection with the use of ILBP. Our data suggest that ILBP provides more effective end-organ protection during repair of aortic arch under moderate HCA.

Effects of early anticoagulation on the degree of thrombosis After repair of acute DeBakey type I aortic dissection.

BACKGROUND: The degree of false lumen thrombosis after surgical repair of acute DeBakey type I aortic dissection can predict long-term outcomes. However, there are currently no evidence-based recommendations for anticoagulation. We analyzed the effect of early anticoagulation on the residual false lumen and long-term outcomes. METHODS: This was a retrospective observational study of 136 patients with acute DeBakey type I aortic dissection who underwent surgical repair between 1997 and 2007. We assessed the effect of early anticoagulation on the degree of thrombosis of the false lumen, segmental growth rates, repeat distal procedures, and long-term survival. RESULTS: Among the 136 patients who underwent operations, imaging data in 103 were sufficient for analyzing the degree of thrombosis of the false lumen. Of those, 56 (54%) received anticoagulation therapy immediately postoperatively. The early-anticoagulation group had a higher proportion of completely patent false lumens and lower partial thrombosis than the no-anticoagulation group. Mean segmental aortic growth rate was significantly lower in the early-anticoagulation group than in the no-anticoagulation group (2.9 ± 1.3 and 4.5 ± 2.8 mm/year, p = 0.0184). Overall survival and aorta-related repeat procedure-free survival were significantly better with early anticoagulation than with no anticoagulation (p < 0.05). CONCLUSIONS: Early anticoagulation after surgical repair of acute DeBakey type I aortic dissection might have a favorable effect on the onset or extension of thrombosis, aortic growth rate, the need for repeat distal procedures, overall survival, and thrombosis-related complications during long-term follow-up.