Laparoscopic right hemicolectomy for an ascending colon cancer patient with an implantable left ventricular assist device: a case report.

BACKGROUND: Left ventricular assist devices (LVADs) currently play an important role in the treatment of patients with end-stage heart failure who require a bridge to heart transplantation or destination therapy. With the development and improvement of the LVADs, the morbidity and mortality rates are declining and life expectancies increasing, and the number of patients with LVADs requiring non-cardiac surgery is likely to increase. We present the case of a patient with implantable LVAD who underwent laparoscopic right hemicolectomy for ascending colon cancer. CASE DESCRIPTION: The patient was a 66-year-old man who underwent LVAD implantation as a BTT 3 years prior. He suffered from severe anemia at follow-up, and a colonoscopy revealed ascending colon cancer. The LVAD pump was implanted in the epigastrium. The long C-shaped subfascial driveline tunnel was made, and driveline exit site was located on the left lateral abdominal wall. We assessed the positional relationship between the tumor and the driveline using X-ray and three-dimensional computed tomography (3D CT) images. 3D CT image allowed us to easily identify the location of the driveline, and we determined to perform laparoscopic right hemicolectomy. The port sites were decided upon carefully to avoid the driveline injury, and the driveline was marked on the skin before surgery. There were no adhesions in the abdominal cavity, and both the LVAD and the driveline were observable. The trocars were in nearly the same positions as in a standard laparoscopic right hemicolectomy. During the operation, the LVAD and the driveline did not interfere with the trocars. We successfully completed a standard laparoscopic right hemicolectomy despite hemorrhagic tendency. The patient was discharged without any bleeding complications during the postoperative course. CONCLUSION: Laparoscopic surgery is feasible and safe for patients with LVADs with intensive preoperative simulation and perioperative prevention of infection.

[Effects of Olmesartan Medoxomil on Patients with Thoracic and Thoracoabdominal Aortic Aneurysm;Evaluation of Anti-hypertensive Effect and Possible Suppression of Aneurysmal Dilation( OLM 40 Study)].

We evaluated the blood pressure( BP) lowering effect and possible suppression of aortic enlargement by olmesartan (OLM) in patients with thoracic and thoracoabdominal aortic aneurysm. In this single center prospective, forced titration study, 50 patients were registered between 2008 and 2011. After all patients received any of OLM 10, 20, and 40 mg/day as an initial dose, the dosage of OLM was titrated up to 40 mg as needed during follow-up period. Home BP (HBPs), aortic aneurysm size assessed by computed tomography (CT) scan, indices of renal function were recorded at 3- and 6-months follow-up. Depending on whether 40 mg/day of prescription was continued for more than 4 months or not, the patients were divided into 2 groups:less than 40 mg (<40 mg) and 40 mg groups. Morning HBPs tended to decrease in both groups, and the percent changes in BPs were essentially the same regardless of dosage. The absolute value of aortic diameter tended to slightly enlarge only in <40 mg group. Also in the <40 mg group, the absolute differences in aortic diameter between those at the time of study registration and each follow-up were 0.5±1.8 mm at 3-month and 1.2±2.3 mm at 6-month (p=0.047),whereas the percent changes were 0.9±3.3% and 2.2±4.5% at 3 and 6 months, respectively( p=0.058). As for 40 mg group, the absolute differences and percent changes did not reach statistically significant increase during the follow-up period. No severe renal dysfunction related to OLM 40 mg prescription was observed. Our results imply that OLM 40 mg may suppress aortic aneurysmal dilation independently of blood pressure lowering effect. Further study with larger number of sample size is warranted to assure this observation.

Preventive effect of low-dose landiolol on postoperative atrial fibrillation study (PELTA study).

OBJECTIVE: To investigate the efficacy of prophylactic administration of low-dose landiolol on postoperative atrial fibrillation (POAF) in patients after cardiovascular surgery. METHODS: Consecutive 150 patients over 70 years of age who underwent cardiovascular surgery for valvular, ischemic heart, and aortic diseases were enrolled in this single-center prospective randomized control study from 2010 to 2014. They were assigned to three treatment groups: 1γ group (landiolol at 1 µg/kg/min), 2γ group (landiolol at 2 µg/kg/min), or control group (no landiolol). In the two landiolol groups, landiolol hydrochloride was intravenously administered for a period of 4 days postoperatively. Electrocardiography was continuously monitored during the study period, and cardiologists eventually assessed whether POAF occurred or not. RESULTS: POAF occurred in 24.4% of patients in the control group, 18.2% in 1γ group, and 11.1% in 2γ group (p = 0.256). Multivariate logistic regression analysis showed that the incidence of POAF tended to decrease depending on the dose of landiolol (trend-p = 0.120; 1γ group: OR = 0.786, 95% CI 0.257-2.404; 2γ group: OR = 0.379, 95% CI 0.112-1.287). Subgroup analysis showed a significant dose-dependent reduction in POAF among categories of female sex, non-use of angiotensin II receptor blockers (ARBs) before surgery, and valve surgery (each trend-p = 0.02, 0.03, and 0.004). CONCLUSIONS: These findings indicate that prophylactic administration of low-dose landiolol may not be effective for preventing the occurrence of POAF in overall patients after cardiovascular surgery, but the administration could be beneficial to female patients, patients not using ARBs preoperatively, and those after valvular surgery.

Nanobubble technology to treat spinal cord ischemic injury.

Background: Spinal cord ischemic injury is a severe complication of aortic surgery. We hypothesized that cerebrospinal fluid (CSF) oxygenation with nanobubbles after reperfusion could ameliorate spinal cord ischemic injury. Methods: Twenty white Japanese rabbits were categorized into 4 groups of 5 rabbits each: sham group, with balloon catheter insertion into the aorta; ischemia group, with spinal cord ischemic injury by abdominal aortic occlusion; nonoxygenated group, with nonoxygenated artificial CSF irrigation after spinal cord ischemic injury; and oxygenated group, with oxygenated artificial CSF irrigation after spinal cord ischemic injury. At 48 hours after spinal cord ischemic injury, the modified Tarlov score to reflect hind limb movement was evaluated. The spinal cord was histopathologically examined by counting anterior horn cells, and microarray and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analyses were performed. Results: The oxygenated group showed improved neurologic function compared with the ischemia and nonoxygenated groups (P < .01 and P = .019, respectively). Anterior horn neuron prevention in the sham, nonoxygenated, and oxygenated groups was confirmed (mean modified Tarlov score: sham, 9.2 ± 1.9; nonoxygenated, 10.2 ± 2.2; oxygenated, 10.4 ± 2.2; ischemia, 2.7 ± 2.7). Microarray analysis identified 644 genes with twofold or greater increased signals between the ischemia and sham groups. Thirty-three genes related to inflammatory response were enriched among genes differentially expressed between the oxygenated and ischemia groups. Interleukin (IL)-6 and tumor necrosis factor (TNF) expression levels were significantly lower in the oxygenated group compared with the ischemia group, while qRT-PCR showed lower IL-6 and TNF expression levels in the oxygenated group compared with the ischemia group (P < .05). Conclusions: CSF oxygenation with nanobubbles after reperfusion can ameliorate spinal cord ischemic injury and suppress inflammatory responses in the spinal cord.

Maximization of the sealing effect of fibrin glue in aortic surgery.

OBJECTIVES: Fibrin glue is used to reinforce anastomosis in aortic surgery. There has not yet been a consensus on how it should be applied optimally. This study aimed to define the optimal condition of applying fibrin glue. METHODS: In experiment 1, we determined the optimal condition for spraying fibrin glue using an expanded polytetrafluoroethylene graft within a needle hole. The length and area of the fibrin cap within the hole were measured. In experiment 2, methods for applying fibrinogen were assessed by comparing brushing and spraying. In experiment 3, swine aorta segments sutured with a Dacron graft were divided into the following three groups: nothing was applied; fibrinogen was sprayed and rubbed using brush. The aorta was clamped and blood was infused from an occlusion catheter inserted into the graft. The pressure at the first appearance of blood leak was recorded. RESULTS: In experiment 1, among the four groups divided by the pressure and distance of spraying, the fibrin cap area in the group with 0.075 MPa and 2-cm spray distance was significantly larger than that in the group with 0.15 MPa and 2 cm (P < 0.01). In experiment 2, the fibrin cap area in the brushing group was significantly larger than that in the spraying group (P < 0.05). In experiment 3, the capacity to resist endoluminal pressure was higher in the brushing and combined spraying group compared with that in the sequential combined spraying group (P < 0.01). CONCLUSIONS: The brush and spray methods showed excellent hemostatic outcomes.

Temporary ventricular assist device implantation by sternotomy-avoiding technique for bridge-to-decision therapy: a comparison with conventional implantation.

OBJECTIVE: Temporary ventricular assist device (VAD) is a commonly used therapeutic option for cardiogenic shock. Patients requiring this treatment are often critical, and clinical outcomes remain unsatisfactory. This study evaluated the feasibility and efficacy of a sternotomy-avoiding technique for temporary VAD implantation to improve patient outcomes. METHODS: Between December 2012 and November 2018, seven patients underwent temporary VAD implantation by sternotomy-avoiding technique (SA group) and eight by median sternotomy technique (MS group). Pre- and intraoperative characteristics, postoperative 7-day hemodynamic parameters, 30-day mortality, and adverse events were compared between the groups. RESULTS: More than 50% of the patients were mechanically supported before temporary VAD implantation. Cardiopulmonary bypass time was significantly shorter in the SA than in the MS group (84 min vs 215 min; p = 0.011); surgical time tended to be shorter in the SA group (385 min vs 461 min; p = 0.064). Pump index, cardiac index, mixed venous oxygen saturation, and central venous pressure did not differ significantly during the first seven days of support. The 30-day incidence of any adverse event was not significantly different between the groups. No patients in the SA group needed re-exploration for surgical bleeding. Thirty-day all-cause mortality rates were 29% in the SA group and 0% in the MS group (p = 0.11). CONCLUSIONS: The sternotomy-avoiding and conventional techniques resulted in comparable short-term hemodynamic support. The sternotomy-avoiding technique was associated with a potential reduction in risk of re-exploration for bleeding. These results support the usefulness of the sternotomy-avoiding procedure for selected patients.

[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.

Concomitant Valve-Sparing Aortic Root Replacement With Repair of Tetralogy of Fallot.

Valve-sparing aortic root replacement is one of the effective repairs for aortic regurgitation resulting from progressive dilatation of the aortic root late after surgical correction of conotruncal anomaly. However, feasibility and effectiveness of this procedure are unknown for unrepaired physiology. A 32-year-old man presented with unrepaired tetralogy of Fallot (TOF) and moderate aortic regurgitation with severe left ventricular dysfunction. Valve-sparing aortic root replacement and TOF repair were simultaneously performed. Six months after the surgical procedure, aortic regurgitation remained trivial. Concomitant valve-sparing aortic root replacement with TOF repair can be feasible and effective for unrepaired TOF with aortic regurgitation.

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.

[Preliminary Results with Implantation of Extracorporeal Ventricular Assist System without Sternotomy Incision].

Temporary mechanical circulatory support device has been highly advocated for severe cardiogenic shock patient. However, standard ventricular assist device (VAD) implantation is invasive procedure for these sick patients. Less-invasive cardiac procedures are known to be generally associated with many beneficial effects such as reduction of trauma, blood loss and risk of infection, and relatively short intensive care unit stay. Here we describe an alternative technique for less invasive extracorporeal VAD implantation.

Morphometrical and biomechanical analyses of a stentless bioprosthetic valve: an implication to avoid potential primary tissue failure.

OBJECTIVES: Stentless bioprosthetic valves provide hemodynamic advantages over stented valves as well as excellent durability. However, some primary tissue failures in bioprostheses have been reported. This study was conducted to evaluate the morphometrical and biomechanical properties of the stentless Medtronic Freestyle™ aortic root bioprosthesis, to identify any arising problem areas, and to speculate on a potential solution. METHODS: The three-dimensional heterogeneity of the stentless bioprosthesis wall was investigated using computed tomography. The ascending aorta and the right, left, and non-coronary sinuses of Valsalva were resected and examined by an indentation test to evaluate their biomechanical properties. RESULTS: The non-coronary sinus of Valsalva was significantly thinner than the right sinus of Valsalva (p < 0.01). Young's modulus, calculated as an indicator of elasticity, was significantly greater at the non-coronary sinus of Valsalva (430.7 ± 374.2 kPa) than at either the left (190.6 ± 70.6 kPa, p < 0.01) or right sinuses of Valsalva (240.0 ± 56.5 kPa, p < 0.05). CONCLUSIONS: Based on the morphometrical and biomechanical analyses of the stentless bioprosthesis, we demonstrated that there are differences in wall thickness and elasticity between each sinus of Valsalva. These differences suggest that the non-coronary sinus of Valsalva is the most vulnerable and at greater risk of tissue failure. The exclusion of the non-coronary sinus of Valsalva may be beneficial to mitigate the long-term risks of tissue failure in the stentless bioprosthesis.

Association between the severity of acquired von Willebrand syndrome and gastrointestinal bleeding after continuous-flow left ventricular assist device implantation.

OBJECTIVES: Acquired von Willebrand syndrome, characterized by the reduction in von Willebrand factor (vWF) large multimers, has recently been considered as one of the causes of gastrointestinal bleeding (GIB). It remains unclear whether its haematological severity is linked with susceptibility to bleeding because the definition of the haematological severity of acquired von Willebrand syndrome has not been precisely determined. This study sought to establish a quantitative methodology to assess the haematological severity of acquired von Willebrand syndrome and to define the threshold for occurrence of GIB in patients implanted with left ventricular assist devices (LVADs). METHODS: In total, 41 patients treated with continuous-flow LVAD implanted between 2011 and 2017 at Tohoku University Hospital were investigated. vWF large multimers were quantitatively evaluated using the 'vWF large multimer index' defined as the ratio of a large multimer proportion in total vWF derived from a patient to that from a normal control. Using this index, the amount of vWF large multimers was expressed as a percentage of its normal control value obtained with a simultaneous analysis of each time measurement. RESULTS: Twelve (29%) patients developed GIB events during follow-up periods (median 591 days) after an LVAD implantation. The vWF large multimer index in patients with GIB was significantly lower than that in those without GIB (25.0 ± 10.3% vs 37.5 ± 17.8%, P = 0.008). Most importantly, all patients experiencing GIB exhibited a vWF large multimer index below 40%. CONCLUSIONS: Patients with GIB exhibited a more severe loss of vWF large multimers. The vWF large multimer index may dictate the risk of GIB after an LVAD implantation. Clinical trial registration number: UMIN000018135.

Suppressive effect of pitavastatin on aortic arch dilatation in acute stanford type B aortic dissection: analysis of STANP trial.

OBJECTIVES: Medical therapy for patients with uncomplicated acute type B aortic dissection (ABAD) is essentially accepted for its excellent early outcome; however, long-term outcomes have not been satisfactory due to aorta-related complications. This trial was performed to investigate the efficacy of a statin as an additive that may enhance the effectiveness of conventional medical treatment in patients with ABAD. METHODS: This was a multi-center, prospective, and randomized comparative investigation of patients with uncomplicated ABAD. Fifty patients with ABAD compatible with inclusion criteria were randomly assigned to two groups and then received administration of pitavastatin (group P) or not (group C). We followed up the patients for 1 year from study onset. RESULTS: Two patients demised during the follow-up period (both were in group C). In addition, aorta-related interventions were performed in two patients (entry closure for aortic dissection by endovascular repair in one patient in each group). Aortic arch diameters at 1 year in group P tended to be smaller than in group C (P = 0.17), and the rate of change of the aortic arch diameters from onset to 1 year was significantly lower in group P (P = 0.046). Multivariate analysis identified patency of the false lumen was detected as a risk factor for aortic arch dilatation (P = 0.02), and pitavastatin intake was a negative risk factor (P = 0.03). CONCLUSIONS: Pitavastatin treatment, in addition to the standard antihypertensive therapy, may have a suppressive effect on aortic arch dilatation in patients with ABAD.

Predictors of Heparin Resistance Before Cardiovascular Operations in Adults.

BACKGROUND: Heparin resistance (HR) is often encountered during cardiovascular operations that require cardiopulmonary bypass. Clinical risk factors and the mechanism underlying heparin resistance are yet to be determined. The aim of this study was to elucidate the clinically valid preoperative predictors related to HR. METHODS: The study evaluated 489 patients undergoing cardiovascular operations. Of these, 25 patients presented with HR and received antithrombin III for the initiation of cardiopulmonary bypass with an effective activated coagulation time. The remaining 464 patients, who did not receive antithrombin III, served as controls (NHR). Preoperative patient demographic and laboratory data were analyzed to identify risk factors for HR. RESULTS: The preoperative laboratory data showed platelet count, fibrinogen, D-dimer, creatinine, and C-reactive protein were significantly higher in the HR group than in the NHR group. As expected, the antithrombin III level was significantly lower overall in the HR group (86.0% vs 95.5%, p = 0.009); however, 80% of the patients in the HR group showed normal antithrombin III levels preoperatively. Multivariable logistic regression analysis identified chronic aortic dissection, chronic obstructive pulmonary disease, smoking, and elevated fibrinogen levels as independent predictors for HR. CONCLUSIONS: HR was shown to be associated with preoperative high fibrinogen levels, a smoking habit, and a preoperative diagnosis of chronic, but not acute, aortic dissection, with chronic obstructive pulmonary disease as comorbidity. Administration of antithrombin III resolved HR in all of the affected patients, even when their preoperative antithrombin III level was within the normal limit.

Is Trisomy 21 a Risk Factor for Rapid Progression of Pulmonary Arteriopathy?　- Revisiting Histopathological Characteristics Using 282 Lung Biopsy Specimens.

BACKGROUND: Pulmonary hypertension (PH) is more progressive in trisomy 21 patients. However, pulmonary arteriopathic lesions in these patients have not been fully characterized histopathologically.Methods and Results:A retrospective review of a lung biopsy registry identified 282 patients: 188 patients with trisomy 21 (Group D) and 94 without (Group N). The mean age at lung biopsy was 3 and 7 months (P<0.0001). Pulmonary arterial pressure (PAP) and pulmonary vascular resistance were similar between the 2 groups. There were no significant differences in the proportion of patients with irreversible intimal lesions or the index of pulmonary vascular disease (IPVD; a measure of the degree of pulmonary arteriopathy progression) between the 2 groups. In addition, after propensity score matching for patient background (n=43 in each group), there were no significant differences in IPVD (P=0.29) or the ratio of irreversible intimal changes between the D and N groups (P=0.39). Multivariate analysis identified age (P<0.0001) and PAP (P=0.03) as the only risk factors for progression of pulmonary arteriopathy. CONCLUSIONS: Histopathologically, early progression of pulmonary arteriopathy in patients with trisomy 21 was not proved compared with patients without trisomy 21. Although we cannot exclude the possibility of bias in the Group D and N patients who were slated for lung biopsy, factors other than pulmonary arteriopathy may affect the marked progression of clinical PH in trisomy 21 patients.

Selective Cerebral Perfusion with the Open Proximal Technique during Descending Thoracic or Thoracoabdominal Aortic Repair: An Option of Choice to Reduce Neurologic Complications.

PURPOSE: Selective cerebral perfusion with the open proximal technique for thoracoabdominal aortic repair has not been conclusively validated because of its procedural complexity and unreliability. We report the clinical outcomes, particularly the cerebroneurological complications, of an open proximal procedure using selective cerebral perfusion. METHODS: A retrospective chart review identified 30 patients between 2007 and 2015 who underwent aortic repair through left lateral thoracotomy with selective cerebral perfusion, established through endoluminal brachiocephalic and left carotid artery and retrograde left axillary artery. RESULTS: The mean durations of the open proximal procedure and cerebral ischemia (the duration of the open proximal procedure minus the duration of selective cerebral perfusion) were 110.3 ± 40.1 min and 24.8 ± 13.0 min, respectively. There were two cases (7%) of permanent neurologic dysfunction (PND) but no in-hospital deaths. Multivariate analysis identified the duration of cerebral ischemia as an independent risk factor for neurologic complications including temporary neurologic dysfunction (TND; odds ratio (OR): 1.13; p = 0.007), but no correlation was found between selective cerebral perfusion duration and neurologic complications. CONCLUSION: Despite the relatively long duration of the open proximal procedure, selective cerebral perfusion has a potential to protect against cerebral complications during thoracic aortic repair through a left lateral thoracotomy.

Predictors of the need for pacemaker implantation after the Cox maze IV procedure for atrial fibrillation.

PURPOSE: The Cox maze IV (CMIV) procedure is being used increasingly frequently for surgical ablation of atrial fibrillation (AF). This study aimed to identify the risk factors of the need for postoperative pacemaker implantation (PMI) after CMIV. METHODS: Preoperative, intraoperative, and postoperative data were retrospectively collected from 67 consecutive patients who underwent CMIV at our institution; 7 (10.4%) required PMI (as a treatment of brady AF or sick sinus syndrome). RESULTS: Patients who needed PMI tended to have lower preoperative heart rates than those who did not on a 12-lead electrocardiogram (ECG; 68.7 ± 11.6 vs. 79.1 ± 18.5 bpm, p = 0.07) and a 24-h ECG (94,772 ± 9800 vs. 109,854 ± 19,078 beats/day, p = 0.03). A multivariate analysis identified a low amplitude of the fibrillatory wave on preoperative ECG as a risk factor of PMI necessity after CMIV [odds ratio = 14.7; 95% confidence interval (CI) 1.9-324.7; p = 0.007] and internal use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEIs/ARBs) as a negative risk factor (odds ratio = 0.16; 95% CI 0.02-0.99; p = 0.049). CONCLUSIONS: A low amplitude of the fibrillatory wave was identified as a risk factor of PMI necessity, whereas the internal use of ACEIs/ARBs diminished the need for PMI. These factors should be considered before CMIV is performed.

Evidence of Pulmonary Vascular Reverse Remodeling After Pulmonary Artery Banding Performed in Early Infancy in Patients With Congenital Heart Defects.

BACKGROUND: Histomorphometric evidence of the effect of pulmonary artery banding (PAB) in infancy on pulmonary vascular reverse remodeling has not been fully described.Methods and Results:We retrospectively reviewed 34 patients who underwent serial lung biopsies before and after PAB.Index of pulmonary vascular disease (IPVD) as a measure of the degree of progression of pulmonary arteriopathy significantly decreased after PAB (1.22±0.25 at 1st and 1.13±0.21 at 2nd biopsy, P=0.04). Additionally,DR=100 µmas an indicator of medial thickness of pulmonary arteries significantly decreased after PAB (15.6±3.7 at 1st and 11.4±2.6 at 2nd biopsy, P<0.0001). Patients were divided into 3 groups by age at PAB: <3 months (Group 1), between 3 and 6 months (Group 2), and >6 months (Group 3). The average secondDR=100 µmof groups 1 and 2 was significantly lower than that of group 3 (11.1±2.2 and 9.8±2.0 vs. 14.9±2.8, respectively; P<0.0001). Additionally, the second IPVD was also significantly lower in groups 1 and 2 than in group 3 (1.1±0.2 and 1.1±0.2 vs. 1.3±0.4, respectively; P=0.02). CONCLUSIONS: Histomorphometric evidence of post-PAB pulmonary vascular reverse remodeling is robust. The magnitude of vascular reversibility is pronounced when PAB is performed before 6 months of age.

Application of actuator-driven pulsed water jet for coronary artery bypass grafting: assessment in a swine model.

Actuator-driven pulsed water-jet (ADPJ) dissection is an emerging surgical method for dissecting tissue without heat and mechanical injury to vessels. We elucidated the mechanical properties of the piezo ADPJ and evaluated its usefulness and safety in coronary artery bypass grafting procedures. The relationship between the input voltage (10-100 V) and peak pressure of the pulsed water jet was evaluated. The tissue strengths of swine internal thoracic and coronary arteries and the surrounding tissues were measured to assure tissue-selective dissection. Internal thoracic arteries were harvested by conventional electric cautery and the water jet in four swine, and eight coronary arteries surrounded by myocardium were attempted to be exposed with the water jet. The dissected specimens were histologically evaluated. The peak pressure of the pulsed water jet was positively correlated with the input voltage (R 2 = 0.9984, P < 0.001). The breaking strengths of the target vessels (internal thoracic and coronary arteries) and the surrounding tissues were significantly different (P = 0.002 and P < 0.001, respectively). Histologic examination revealed that internal thoracic arteries were isolated with less heat damage using the pulsed water jet (P = 0.002) compared with electric cautery, and coronary arteries also were dissected without apparent histologic damage. ADPJ has the possibility of assuring tissue selectivity among the internal thoracic and coronary arteries. The results also indicated that the use of ADPJ may enhance safe procedures to harvest grafts during coronary artery bypass grafting.