Pre-clinical assessment of a prototype non-invasive diagnostic device to detect aortic aneurysms.

We have developed a non-invasive diagnostic device for treating thoracic aortic aneurysm that can be applied at a peripheral artery. This study aimed to examine how configuration and size of an aneurysm as well as endoluminal pressure affect our diagnostic device's ability to detect an aneurysm, using a pulsatile mock circulation. We created three different-sized (12, 16, and 20 mm) saccular and fusiform aneurysm models using silicone and incorporated them in a pulsatile perfusion circuit to evaluate vertical vessel wall velocity wave form at a location apart from the aneurysm. We also varied the pressure condition to evaluate the changes in the detected wave forms. In both fusiform and saccular aneurysm models, biphasic wave forms indicating the presence of aneurysm within the circuit were observed. Regarding aneurysm diameter, biphasic wave forms were observed in all aneurysm models. However, in the 12-mm model, which is relevant to the minimum diameter of clinical diagnostic criteria for an aneurysm relative to normal size, no biphasic waveform was detected when the endoluminal pressure was relatively low. In the 16- and 20-mm models, biphasic waveform was detected without being affected by the configuration and endoluminal pressure. The detectability of aneurysms within a pulsatile mock circulation using our non-invasive diagnostic device was not affected by the clinically relevant configuration and size of the aneurysm under slightly hypertensive endoluminal pressure condition. Low endoluminal pressure may lower the diagnostic sensitivity for relatively small saccular aneurysm.

[Splenic Injury during Replacement of the Thoracoabdominal Aorta].

Extraperitoneal approach is commonly employed for thoracoabdominal aortic repair via Stoney incision. It is supposedly rare to encounter abdominal visceral bleeding during that procedure. However, the spleen may spontaneously adhere to the adjacent peritoneum, which could induce incidental injury to the spleen by its anterior mobilization during extraperitoneal approach. Unless we bare its potential risk in mind, bleeding from the spleen may be overlooked, which results in hemodynamic deterioration. We have experienced 3 cases of splenic injury that necessitated hemostatic maneuvers for bleeding during and just after the thoracoabdominal aortic repair.

[Clinical Results of Thoracic Endovascular Aortic Repair (TEVAR) for the Treatment of Aortic Arch Aneruysm].

Thoracic endovascular aortic repair( TEVAR) combined of neck branch reconstruction( debranching TEVAR:dTEVAR) is applied to aortic arch aneurysm for minimally invasive reduction and improvement of treatment results. We report the initial and long-term results of dTEVAR for the treatment of aortic arch aneurysm. TEVAR for zone 0-2 area was applied in 49 cases (Zone 0:1:2;8:5:36 cases). Total dTEVAR was applied in zone 1 cases and 2 dTEVAR was performed in zone 2 cases. One dTEVAR or TEVAR with simple coverage of left subclavian artery was applied in zone 2 cases. Operative mortality within 30 days was 0% and there was 1 case in hospital death due to coronary arterial rupture after percutaneous coronary intervention. Perioperative morbidity included 1 case(2.0%) spinal cord ischemia, 4( 8.2%)arm claudication. In long-term follow-up, 5 cases died during the observation period (stroke in 1 case, heart failure in 1, neoplasma in 2, unknown in 1), but not in aortic rupture. Secondary type1 endoleak occurred in 2 cases(4.1%). Graft occlusion for neck branch reconstruction was complicated with 3 cases(6.1%), however no complications related to the graft occlusion. Our strategy of TEVAR provided durable results in patients treated for aortic arch aneurysm, with few adverse events.

Frequency and chaotic analysis of pulsatile motion of blood vessel wall related to aneurysm.

BACKGROUND/OBJECTIVE: In this research, using our proposed method, clinical measurements on the pulsatile velocity of blood vessel wall were conducted for cases with aneurysm. Furthermore, detailed analyses of frequency and attracter of trajectories of velocity of blood vessel wall were conducted. On the basis of these analyses, we tried to conduct unified clarification of the change and disturbance of frequency and wave form of pulsatile velocity of blood vessel wall caused by blood vessel diseases such as aneurysm. RESULTS: In the pulsation motion of blood vessel wall, vasomotion, which is a regular long periodic fluctuation of amplitude of the pulsatile velocity of blood vessel wall, was found to exist. Furthermore, the shift of its frequency into low frequency region was found to correspond well with an increase in I∗, an indicator of progressive degree of visco elasticity of blood vessel wall and it reflects the mechanical deterioration of blood vessel wall. This long periodic fluctuation of amplitude of the pulsatile velocity of blood vessel wall exists in the low frequency region that composes the frequency of the pulsatile velocity of blood vessel wall. On the other hand, wave forms in high frequency region that compose the frequency of pulsatile velocity of blood vessel wall were found to correspond well with each pulsatile velocity wave form of blood vessel wall itself and their disturbances caused by the existence of aneurysm was typically reflected in these wave forms. CONCLUSION: By dividing frequencies that compose the frequency of the pulsatile velocity of blood vessel wall into low and high frequency regions and conducting analyses at each region, the possibility of accurate selective detection of blood vessel diseases such as mechanical deterioration of blood vessel wall (low frequency region) and morphological change of blood vessel wall that is aneurysm (high frequency region) was indicated.

A novel diagnostic system for Doppler ultrasound of the peripheral arteries to detect the presence of thoracic aortic aneurysm.

OBJECTIVE: We aimed to develop a novel ultrasound system and examine its feasibility for noninvasively detecting thoracic aortic aneurysm (TAA) in clinical settings. METHODS: We developed a novel ultrasound system consisting of a modified console and data analysis algorithm. The exploratory study included 100 patients hospitalized for elective cardiovascular surgery. After admission, the arterial pulse waveform at the left carotid artery was acquired using the novel system. Based on these data, we inferred the presence of TAA based on arterial viscoelasticity and instability, which are reflected into the time-averaged trajectory of deformation of the blood vessel wall caused by disturbance of blood flow. Meanwhile, all patients underwent computed tomography as preoperative screening to confirm the presence of TAA. The sensitivity and specificity of TAA detection using the novel ultrasound system were calculated. RESULTS: The datasets from 37 patients were not suitable for analysis and were thus discarded. Based on computed tomography findings, 40 patients were categorized into the aneurysm group while 23 were judged not to have and aortic aneurysm. On the other hand, 44 patients were diagnosed as having TAA based on ultrasound findings obtained using the novel system. The overall sensitivity and specificity of the ultrasound system were 0.83 and 0.52, respectively. CONCLUSION: We successfully developed a novel system for noninvasive, ultrasound-based evaluation of the left carotid artery to detect TAA. Although improvements to the probe and diagnostic algorithm are warranted, this device has potential utility for mass screening to detect asymptomatic TAA as part of community-level healthcare programs.

Differential selective hypothermic intercostal artery perfusion: a new method to probe spinal cord perfusion during thoracoabdominal aortic aneurysm repair.

OBJECTIVE: To prevent paraplegia in patients undergoing thoracoabdominal aortic aneurysm repair, the importance of preoperative identification of the Adamkiewicz artery and reconstruction of critical intercostal artery have been advocated. Conversely, significance of collateral network for spinal cord perfusion has been recognized. We invented a new system consisting of a direct monitoring of cerebrospinal fluid temperature (CSFT) and differential selective hypothermic intercostal artery perfusion (D-HIAP). METHODS: After exposing a critical intercostal artery, a 10-mm prosthetic graft was anastomosed in an end to side fashion. A balloon-tipped catheter was inserted into the graft to perfuse with 15 °C blood. Neighboring intercostal arteries were also perfused in the same fashion. Serial monitoring of CSFT was performed. Between January 2011 and January 2015, D-HIAP was employed in 50 patients with Adamkiewicz artery that located within a reconstructed area. RESULTS: Significant CSFT drop was recorded after initiation of D-HIAP in 42 (84%) patients. Of those, 34 (68%) patients showed significantly lowered CSFT with D-HIAP into a single critical intercostal artery. Perfusion into plural intercostal arteries was necessary for CSFT drop in 2 cases (4%), and plural intercostal artery perfusion further enhanced CSFT drop that had been modestly achieved by single intercostal artery perfusion in 6 cases (12%). Eight (16%) patients did not exhibit a significant drop in CSFT even when D-HIAP was employed for the critical and neighboring intercostal arteries. CONCLUSIONS: The detection of a disparity in temperature between the intrathecal space and blood generated by D-HIAP revealed individual variability in CSFT changes, which may imply a complexity in spinal cord perfusion. Intraoperative D-HIAP may help to identify a major blood supply for spinal cord perfusion and underlying collateral network.

Safety and durability of the biodegradable felt in aortic surgery: a propensity score-matched study.

OBJECTIVES: Suture line disruption is a serious complication after aortic surgery. We previously reported in a canine model that basic fibroblast growth factor-incorporated biodegradable polyglycolic acid (PGA) felt prevented tissue derangement at the anastomotic site. This study sought to evaluate the safety and durability of this biodegradable felt. METHODS: Between January 2007 and December 2011, 67 patients who consented to undergo aortic surgery with the basic fibroblast growth factor-incorporated PGA felt were enrolled (Group P). As a control, we retrospectively reviewed the charts of 129 patients who underwent aortic surgery using a polytetrafluoroethylene felt during the same registration period (Group N). On the basis of 18 preoperative covariates, 60 well-matched patient pairs were identified using propensity matching, and their clinical indices were compared. RESULTS: Among the matched pairs, in-hospital mortality and postoperative complication rates did not statistically differ between the groups. During a median follow-up of 4.8 years, the rate of anastomotic aneurysm was 1.7% (1 patient) in both groups. The rates of overall survival and freedom from aortic events did not differ between the groups. In total, 65 anastomoses in Group P and 54 anastomoses in Group N were monitored via computed tomography, and the diameters of the juxta-anastomotic sites in Group N were more likely to be increased than those in Group P {dilatation ratio [(post-discharge diameter - predischarge diameter)/predischarge diameter × 100 (%)]: 4.3% ± 0.6% vs 2.5% ± 0.5%, P = 0.01}. CONCLUSIONS: The basic fibroblast growth factor-incorporated PGA felt was as safe and durable as conventional felt for reinforcement in aortic surgery. The attenuation of juxta-anastomotic aortic dilatation by PGA felt reinforcement may provide more beneficial effects on long-term outcomes.