Acute Effect in Mechanical Efficiency by Pressure-Volume Loop Analysis after Transcatheter Aortic Valve Implantation.

Background: This study aimed to evaluate the immediate effect of transcatheter aortic valve implantation (TAVI) on mechanical efficiency. Methods: A total of 46 patients (25 females) with an average age of 83 ± 6.4 years underwent TAVI using the CoreValve system. During the same hospitalization, we conducted a comprehensive comparison of the patients before and after TAVI without inotropic support using echocardiography. The parameters encompassed left ventricular (LV) geometry, valvular load, global LV afterload and ventricular hemodynamics. The analysis using pressure-volume loops enabled the determination of load-independent contractility (Ees) and afterload, in addition to assessing potential energy, stroke work, and mechanical efficiency. Results: The immediate effect was an augmented aortic valve area accompanied by a reduction in the transvalvular pressure gradient. We observed reductions in left ventricular end-systolic volume and end-diastolic volume, and also reductions in global afterload and end-systolic meridional wall stress. The Ea index decreased, while the Ees index remained relatively stable. We noted increases in stroke volume and systemic arterial compliance, indicating more efficient blood transfer from the ventricle to aorta. These changes contributed to the normalization of ventricular-arterial coupling. In terms of mechanical work of the chamber, we observed significant decreases in potential energy, stroke work, and pressure-volume area. There was an increase in the mechanical efficiency of the chamber. Conclusions: The TAVI procedure immediately reduced global afterload and improved diastolic compliance of the chamber, resulting in enhanced ventricular function and mechanical efficiency.

Endovascular Aortic Arch Reconstruction with Parallel Grafts: A Dilemma of Excessive Endograft Oversizing.

BACKGROUND: Preservation of supra-aortic branches in thoracic endovascular aortic repair plays a role in associated neurological outcomes, and the strategy varies. OBJECTIVES: This study aimed to evaluate the safety and efficacy of a parallel graft technique to reconstruct the aortic arch. METHODS: From August 2014 to July 2018, a total of 25 patients with thoracic aortic pathologies requiring arch reconstruction were included. All patients underwent thoracic aortic endovascular repair (TEVAR) with a zone 1 landing aortic stent graft, a chimney graft to preserve the left common carotid artery, and a periscope graft to preserve the left subclavian artery. The associated outcomes and complications were reported. RESULTS: Eighteen patients presented with aortic dissection, 4 with a thoracic aortic aneurysm, 1 with a penetrating aortic ulcer, 1 with a traumatic aortic injury, and 1 case of re-TEVAR. The technical success rate was 96% (24/25), but the case of immediate failure died of retrograde type A dissection. Over a mean follow-up of 32.33 months, another retrograde type A aortic dissection was detected in 1 month, and a case of early failure (< 1 year) and 3 cases of late failure (> 1 year) whose primary aortic problems recurred were detected. CONCLUSIONS: This study demonstrates a total endovascular approach to preserve supra-aortic branches with a parallel graft technique. However, the dilemma of excessive graft oversizing was disclosed due to the risk of retrograde type A dissections and an unsatisfactory durability in this small series.

The Sandwich Technique with Body Flossing Wire to Revascularize Left Subclavian Artery in Thoracic Endovascular Aortic Repair.

BACKGROUND: To evaluate the safety and efficacy of the sandwich technique with the body flossing wire to revascularize the left subclavian artery (LSA) in thoracic endovascular aortic repair (TEVAR). METHODS: From April 2014 to April 2015, 20 consecutive patients with a variety of thoracic aortic pathologies who underwent LSA revascularization with the sandwich technique and body flossing wire during TEVAR were included. Outcomes including technical success, endoleaks, perioperative mortality and morbidity, and graft patency were analyzed. RESULTS: There were 13 patients (65.0%) who presented with aortic dissection, 3 (15.0%) with thoracic aortic aneurysm, 3 (15.0%) with penetrating aortic ulcer, and 1 (5.0%) with traumatic aortic disruption. Technical success rate was 100%. But one type Ia endoleak (5.0%) was noted and treated with extended endografting. One sandwiched gutter leak (5.0%) resolved spontaneously at 6 months. One sandwiched graft (5.0%) was occluded but not treated because no related complications were found. At a mean follow-up of 9.7 months (range 4-17), all the patients with aortic aneurysm, penetrating aortic ulcer, or traumatic aortic disruption had complete thrombosis of the aortic pathologies. Patients with aortic dissection had thrombosed false lumen down to the distal aortic endograft edge (12/13, 92.3%) or the celiac artery level (8/13, 61.5%). There was no neurological deficit but 2 non-procedure-related late deaths during the study period. CONCLUSIONS: Our early experience showed that the sandwich technique with the body flossing wire to maintain blood flow to the LSA is a safe and effective method. This technique can be applied in various clinical situations with a high technique success rate. However, outcomes are preliminary and larger studies are required.

Intraoperative Measurement of Fractional Flow Reserve in Off-Pump Coronary Artery Bypass: A Pilot Study.

BACKGROUNDS: Fractional flow reserve of myocardium (FFRmyo) is a functional study of significant coronary artery stenosis, defined as the ratio of the pressure distal to the stenosis (poststenosis) divided by the pressure of aortic root (prestenosis). Instead of cath laboratory, we could measure it in operating room for off-pump coronary artery bypass (OPCAB) surgery and here shared our methods in the pilot study. METHODS AND RESULTS: We used needles, catheters, and pressure tracing but without guidewires or fluoroscopy to measure FFRmyo during OPCAB. In February 2010, we conducted the pilot study and collected 32 anastomosis data from 10 patients. Without revising the anastomosis plans based on coronary angiographies, 24 FFRmyo of the 32 anastomoses (75%) were less than 0.75, which represented significant functional stenosis. The FFRmyo measurements did not lead to any adverse events. CONCLUSION: The measurement of fractional flow reserve in OPCAB is safe and feasible. It can serve as a functional assessment of coronary artery stenosis in adjuvant to conventional coronary angiography.

Reducing Left Ventricular Wall Stress through Aortic Valve Enlargement via Transcatheter Aortic Valve Implantation in Severe Aortic Stenosis.

Background: In aortic stenosis, the left ventricle exerts additional force to pump blood through the narrowed aortic valve into the downstream arterial vasculature. Adaptive hypertrophy helps to maintain wall stress homeostasis but at the expense of impaired compliance. Advanced ventricular deformation impacts the extent of functional recovery benefits achieved through transcatheter aortic valve implantation. Methods and Results: Subgroups were stratified based on output, with low-flow severe aortic stenosis defined as stroke volume index <35 mL· m-2. Before intervention, the low-flow subgroup exhibited worse effective orifice area index and arterial and global impedance, along with thinner wall thickness and larger chamber volume marginally. LV performance, including stroke volume index, ventricular elastance, and ventricular-arterial coupling, were notably inferior, consistent with worse adverse remodeling. Although the effective orifice area index was similarly augmented after TAVI, inferior recovery benefits were noted. Persistently higher wall stress and energy consumption were observed, along with poorer ventricular-arterial coupling. These changes in wall stress showed an inverse relationship with alterations in wall thickness and were proportional to changes in dimension and volume. Additionally, they were proportional to changes in left ventricular end-systolic pressure, pressure-volume area, and ventricular-arterial coupling but inversely related to ventricular end-systolic elastance. Conclusions: The study revealed that aortic valve enlargement through transcatheter aortic valve implantation reduces left ventricular wall stress in severe aortic stenosis. The reduced recovery benefits in the low-flow subgroup were evident. Wall stress could serve as a marker of mechanical benefit after the intervention.

Impact of Recurrent Mitral Regurgitation on Left Ventricular Mass Regression and Cardiac Events following Mitral Valve Repair.

BACKGROUND: Mitral valve regurgitation results in volume overload, followed by left ventricular remodeling. Variation of reverse remodeling following mitral repair influences the clinical outcomes. We aimed to evaluate the association between recurrent mitral regurgitation and mass regression following mitral valve repair and the impact on major adverse cardiovascular events. METHODS: A retrospective cohort study was conducted on 164 consecutive patients with severe mitral regurgitation who underwent elective mitral valve repair. Subgroups were classified based on the presence of recurrent mitral regurgitation exceeding moderate severity. The hemodynamic parameters were evaluated according to geometry, mass, and function with Doppler echocardiography before and after surgery. Cox regression analysis was performed to evaluate the association between hemodynamics and mass regression and clinical outcomes. RESULTS: The results for MR indicated 110 cases with non-recurrent MR and 54 with recurrent MR, along with 31 major adverse cardiovascular events. The tracked echocardiographic results revealed less reduction in dimension and volume, along with less mass regression in the recurrent MR subgroup. Significant differences were revealed in the relative change of the LV end-diastolic volume index and relative mass regression between subgroups. The relative change in the LVEDVI was proportionally correlated with relative mass regression. Cox regression analysis identified correlations with major adverse cardiovascular events, including suture annuloplasty, recurrent mitral regurgitation, tracked LV mass, relative LV mass regression, and systolic dysfunction. CONCLUSION: LV mass regression and relative change of the LV end-diastolic volume could be risk predictors of recurrent mitral regurgitation. The extent of LV mass regression is correlated with adverse cardiac events.

Extent of Left Ventricular Mass Regression and Impact of Global Left Ventricular Afterload on Cardiac Events and Mortality after Aortic Valve Replacement.

Patient-prosthesis mismatch (PPM) causes a high transvalvular pressure gradient and residual left ventricular (LV) hypertrophy, consequently influencing long-term results. This study aimed to find the relationships between hemodynamic parameters and LV mass regression and determine the risk predictors of major adverse cardiovascular and cerebral events (MACCE) after aortic valve replacement (AVR) for aortic stenosis. Methods and Results: Preoperative and postoperative Doppler echocardiography data were evaluated for 120 patients after AVR. The patients' mean age was 67.7 years; 55% of the patients were male. Forty-four (37%) patients suffered from MACCE during a mean follow-up period of 3.6 ± 2 years. The following hemodynamic parameters at follow-up were associated with lower relative indexed LV mass (LVMI) regression: lower postoperative indexed effective orifice area, greater mean transvalvular pressure gradient (MPG), greater stroke work loss (SWL), and concentric or eccentric LV remodeling mode. The following hemodynamic parameters at follow-up were associated with a higher risk of MACCE: higher valvuloarterial impedance (ZVA), greater SWL, greater MPG, greater relative wall thickness, greater LVMI, and hypertrophic LV remodeling mode. Lower relative LVMI regression was associated with a higher risk of MACCE (hazard ratio, 1.01: 95% confidence interval, 1.003-1.03). The corresponding cutoff of relative LVMI regression was -14%. Conclusions: Changes in hemodynamic parameters were independently associated with relative LVMI regression. Impaired reverse remodeling and persistent residual LV hypertrophy were independent risk predictors of MACCE. An LVMI regression lower than 14% indicated higher MACCE. A postoperative ZVA greater than 3.5 mmHg/mL/m2 was an independent risk predictor of cardiac events and mortality after AVR. Preventive strategies should be used at the time of the operation to avoid PPM.

Recurrent cervical carcinoma presenting as a primary aortoduodenal fistula.

Aortoduodenal fistula is a rare cause of gastrointestinal (GI) bleeding, and carries high morbidity and mortality even in modern practice. Cervical carcinoma is a major health threat among adult women, and its recurrence is not uncommon. We herein present a case of primary aortoduodenal fistula because of recurrent cervical carcinoma. Our case demonstrated that diagnosis of primary aortoenteric fistula requires a high index of suspicion and a combination of diagnostic modalities to establish the diagnosis. Prompt diagnosis and rapid treatment are critical in reducing mortality and morbidity. Although rare, metastatic carcinoma can lead to aortoenteric fistula.

Handmade fenestrated stent grafts to preserve all supra-aortic branches in thoracic endovascular aortic repair.

OBJECTIVE: To evaluate the efficacy and safety of a zone 0 landing aortic stent graft with handmade fenestrations for the preservation of all supra-aortic branches in thoracic endovascular aortic repair (TEVAR). METHODS: This study included 13 consecutive patients who underwent TEVAR using zone 0 landing handmade fenestrated stent grafts to preserve all supra-aortic branches from July 2016 to April 2017. Technical success was defined as the resolution of the primary aortic pathology as well as the preservation of all supra-aortic branches through the accurate alignment of the fenestration. Outcomes including technical success, perioperative morbidity and mortality, requirement of secondary interventions, and graft patency were analyzed. RESULTS: In this study, 11 patients presented with aortic dissection, 1 presented with thoracic aortic aneurysm with impending rupture, and 1 presented with penetrating aortic ulcer of the thoracic aorta. The technical success rate of the primary procedure was 100%. Over a mean follow-up of 20 months, secondary endovascular procedures were performed in 6 patients to resolve 3 cases of stent graft-induced new entry, 2 cases of type Ib endoleak, and 1 case of new false lumen formation. During the study period, no complication resulting from proximal landing and fenestration occurred. CONCLUSIONS: Our experience of using handmade fenestrated stent grafts revealed preliminary results of using the grafts to preserve all supra-aortic branches in TEVAR, and results demonstrated the feasibility of this technique for achieving total arch replacement endovascularly in selective patients. Further technical advancement is anticipated, and larger studies with long-term follow-up are required.

Reverse-loop upper arm arteriovenous graft for chronic hemodialysis.

Options for an upper arm arteriovenous graft (AVG) commonly include the placement of a straight prosthetic graft connecting the brachial artery to the axillary vein. However, such configuration leads to underutilization of the upper arm veins, resulting in the loss of venous capital in the upper arm for future secondary fistula creation. In this retrospective analysis, we evaluated seven patients who had upper-arm AVGs created in a reverse-loop configuration. The prosthetic graft was created by connecting the brachial artery close to the cubital fossa and tunneled subcutaneously in a looped fashion distally thereby connecting the basilic or deep brachial vein just above the elbow. Endpoints were interventions, thrombosis, and loss of access at the last examination. The brachial vein was used in two patients and the basilic vein in the other five. The median duration of follow-up with 100% patency of the AVGs was 10.0 (range, 3.0-25.0) months. Patients were able to achieve a target hemodialysis dose with a (K(urea) x t(d))/V(urea) value of 1.4 (range, 1.2-1.5). The median flow rates achieved were 205.0 (range, 203.3-236.7) and 266.7 (range, 203.3-276.7) ml/minute at the first and 3-month dialysis sessions, respectively. The median dialysis venous pressures were 128.0 (range, 108.3-178.0) and 131.0 (range, 116.7-148.7) mmHg at the first and third month after operation, respectively. The median peak systolic velocity ratios of artery-graft and vein-graft junctions were 2.1 (range, 1.4-2.4) and 3.0 (range, 2.3-3.8) cm/second, respectively. In conclusion, this is a logical approach for patients who have exhausted their forearm vessels for AVG creation. In addition, it also provides a platform for future creation of a secondary fistula in the upper arm.

Handmade stent graft fenestration to preserve left subclavian artery in thoracic endovascular aortic repair†.

OBJECTIVES: This study aimed to evaluate the efficacy and safety of a handmade fenestrated stent graft over an aortic stent graft for preserving the left subclavian artery (LSA) in thoracic endovascular aortic repair (TEVAR). METHODS: From July 2015 to October 2018, a total of 32 consecutive patients with various thoracic aortic pathologies who underwent TEVAR in which handmade fenestration over a thoracic aortic stent graft was used for LSA were included. Outcomes including technical success, procedure-related complications, perioperative mortality and morbidity and graft patency were analysed. RESULTS: Twenty-four patients (75.00%) presented with aortic dissection, 5 patients (15.63%) with thoracic aortic aneurysm and 2 patients (6.25%) with penetrating aortic ulcer; 1 patient (3.13%) required re-TEVAR due to endoleak and sac expansion from previous TEVAR for thoraco-abdominal aneurysm. TEVAR was performed in a zone 2 landing with single fenestration for LSA (26 patients, 81.25%), zone 1 landing with double fenestration for both LSA and left common carotid artery (5 patients, 15.63%) or zone 1 landing with single fenestration for LSA and a chimney graft for left common carotid artery (1 patient, 3.13%). The technical success rate, defined as the successful alignment of fenestration to LSA, was 93.75%. At a mean follow-up of 17.3 months, 4 cases of endoleak and 2 cases of stent graft-induced new entry were noted, 3 of which were treated endovascularly. CONCLUSIONS: Our preliminary results demonstrate the viability of preserving LSA blood flow in TEVAR using a handmade stent graft fenestration to treat various aortic pathologies in various clinical situations and the technical feasibility and short-term results that may justify the use of this method in emergency cases.

Total laparoscopic repair for abdominal aortic aneurysm.

Surgical resection and grafting have long been the standard treatment for abdominal aortic aneurysm and provide an excellent long-term outcome. However, there is tremendous impact on patients due to the surgical invasiveness. Endovascular aortic repair using stent graft was introduced in 1991. After refinement of the techniques and technology, endovascular aortic repair was approved by most health authorities and is associated with less periprocedural morbidities. In between these two extremes, some surgeons endeavored to create an alternative and perform less invasive surgeries. Hand-assisted laparoscopic aortic surgery and laparoscopic-assisted aortic surgery were introduced in 1996. In 2001, total laparoscopic abdominal aortic aneurysm resection with tube graft interposition was first performed in Canada. Till now, only a few vascular units in North America and Europe perform these delicate techniques. We report our first case of total laparoscopic abdominal aortic aneurysm repair. Laparoscopic aortic surgery provides better visualization of the aneurysm neck, less bowel manipulation and avoidance of hypothermia. The minimal invasiveness could translate to better perioperative outcome. To our knowledge, this is also the first case report in Asia. The detailed techniques are described.

Spiral saphenous vein graft for portal vein reconstruction in pancreatic cancer surgery.

The curative strategy for most pancreatic cancer is surgical resection. Extensive resection with lymph node dissection is the key to providing long-term survival. However, early diagnosis of pancreatic cancer is not always possible (ie, resectability is limited). One reason for such a nonresectable condition is vascular invasion or encasement. Portal vein involvement has been a contraindication for pancreatic cancer surgery for most general surgeons. Combining oncologic and vascular surgeons in the procedure has been a good solution. A multidisciplinary approach that includes general and vascular surgeons is appropriate in selected patients requiring vascular reconstruction at the time of pancreatectomy. The objective of this paper is to report a case in which spiral saphenous vein was used for portal vein reconstruction during pancreatic cancer resection.

Less invasive mitral valve surgery via right minithoracotomy.

BACKGROUND/PURPOSE: Current trends in cardiac surgical intervention are moving toward less invasiveness, with smaller wound or sternum-sparing, less pump time or off-pump, and beating rather than arrested heart. Data on the efficacy and safety of these newer less invasive techniques, as well as their cosmetic results, are limited. This study analyzed the results of a sternum-sparing mitral valve operation. METHODS: Thirty patients with mitral valve diseases, including 20 who underwent mitral valve repair and 10 mitral valve replacement, were enrolled. Cardiopulmonary bypass was established via femoral cannulation, and blood cardioplegic arrest was induced by using a percutaneous, transthoracic cross-clamp. The main surgical wound was made over the lateral border of the right breast. Two additional small wounds were required for the transthoracic aortic clamp and the mitral retractor. RESULTS: There was no operative mortality, and all patients had an uneventful recovery. Two patients underwent redo mitral surgery. Nine associated procedures were performed including tricuspid valve annuloplasty in six patients, tricuspid valve replacement in two patients and atrial septal defect repair in one patient. The length of the main wound was between 5.8 and 7.8 cm (mean, 7.1 cm). The mean cardiopulmonary bypass time and cross-clamp time were 91.1 and 43.7 minutes, respectively. Although the length of stay was not significantly reduced compared with traditional median sternotomy, all patients had satisfactory results with good cosmesis. CONCLUSION: Sternum-sparing mitral valve surgery appears to be a safe and effective alternative to conventional mitral valve surgery; it is less invasive and provides superior cosmetic results for patients.

Endoscopic radial artery harvest for coronary artery bypass surgery.

BACKGROUND/PURPOSE: Coronary artery bypass grafting (CABG) provides better long-term patency than percutaneous intervention in patients with significant coronary artery disease. The radial artery is the second most common arterial conduit used for CABG in Western countries. However, radial artery harvesting necessitates a large surgical wound and has gained few patients' acceptance in subtropical areas. This study investigated the use of the minimally invasive approach of endoscopic radial artery harvest for CABG, and the surgical results at the harvest site. METHODS: An endoscopic harvest program for radial arteries was implemented in this hospital in September 2003. During the first 12 months of the program until September 2004, 122 patients underwent the procedure. Preoperative evaluation included Allen's test and the modified palmar arch perfusion test. The age of patients ranged from 32 to 88 years old. Patients were excluded from participation if they had undergone recent transradial catheterization, had end-stage renal disease or documented peripheral artery occlusive disease. The VasoView system was utilized for the procedure. Details of the surgical techniques used were recorded and analyzed. RESULTS: Using the endoscopic technique, 122 radial arteries were harvested successfully. The mean resting length of the harvested radial artery was 15.7 cm. No obvious arterial injury was visually confirmed. All radial arteries were used for CABG, except for two which were noted to have atherosclerotic plaques causing stenoses. Forty-seven patients presented with mild numbness over the dorsum of the thumb base, which improved significantly during the 3-month follow-up. No arterial insufficiency in the forearms or hands was noted. CONCLUSION: Endoscopic harvest of the radial artery is technically demanding, but excellent results can be achieved. The endoscopic approach can provide suitable conduits in a less invasive way than the open harvest technique.