Review of current status of cardiovascular and thoracic surgery in Nepal: An analysis from collection of institutional database.

OBJECTIVE: Data collected from various institutions around the country was analyzed to assess the current status of cardiovascular and thoracic surgery in the country. METHODS: We collected data from institutions performing cardiovascular and thoracic surgery from all over the country through direct correspondence for the year 2019. Individual institution data on the number of surgeries performed for cardiac, vascular, and thoracic surgery and its outcome in terms of mortality were compiled. The data were further evaluated depending on the type of procedures performed. RESULTS: Overall, a total of 2264 cardiac surgeries were performed in the country in the year 2019. The majority of the surgeries were for valvular heart surgery accounting for 34.3%, followed by congenital surgeries (32.8%) and surgeries for coronary artery disease (25.9%). A total of 649 thoracic surgeries were documented, which is probably marginally less than the actual numbers because we were unable to include an additional few institutions performing low-volume or isolated thoracic procedures in this report. A total of 852 vascular procedures were performed in the country, which is probably underreported. The mortality rates for complex congenital procedures were higher than those reported in the literature and that of adult procedures such as valvular heart disease and coronary artery disease similar to literature. CONCLUSION: We evaluated the recent status of cardiovascular and thoracic surgery in the country with respect to the type of procedures and the postoperative outcomes.

Pericardial cyst in a one-year-old boy with ventricular septal defect and patent ductus arteriosus.

BACKGROUND: Pericardial cysts are rare, with the most common etiology being congenital. Ventricular septal defect is the most common congenital heart disease in children. However, the combination of pericardial cyst, ventricular septal defect, and patent ductus arteriosus is extremely rare. CASE PRESENTATION: A one-year-old boy with ventricular septal defect and patent ductus arteriosus was planned for surgical correction. Intraoperatively, we made an additional diagnosis of a large pericardial cyst; and the cyst was excised along with ventricular septal defect closure and patent ductus arteriosus ligation. CONCLUSIONS: Pericardial cysts can sometimes be missed with transthoracic echocardiography. Excision of the cyst can safely be done during concomitant cardiac surgery.

Elective re-intubation to treat complete left lung collapse following Tetralogy of Fallot repair in a very young child.

An 18-month-old boy weighing 6 kilograms developed complete collapse of left lung following total correction of Tetralogy of Fallot on the next day of extubation. He received extensive chest physiotherapy, along with lung recruitment maneuver by using bubble CPAP, which failed to show any improvement in lung expansion in 2 days. He was then electively intubated on 3rd postoperative day (POD3) for the purpose of suctioning tracheobronchial secretions and maintaining positive airway pressure to open up the left lung. Good results were obtained immediately after intubation, and he was extubated 9 h later. His lung showed complete aeration afterward. He was transferred out of ICU on POD5 and discharged home on POD10.

Evaluation of spinal cord protective threshold of serum memantine, an NMDA receptor antagonist, in a rabbit model of paraplegia.

PURPOSE: To evaluate the threshold of serum memantine for prevention of spinal cord injury (SCI) in a rabbit paraplegic model. METHODS: Forty-two New Zealand white rabbits were divided into 7 groups. Preoperatively, oral memantine was given starting from 60 mg OD for 7 days in the initial group, then reducing the dose and/or duration to 60 mg OD for 5 days, 30 mg OD for 5 days, 30 mg OD for 3 days, 15 mg OD for 3 days, 30 mg single dose, and 60 mg single dose, in subsequent 6 groups. A paraplegic model was created by clamping both infrarenal aorta and inferior vena cava (IVC) for 45 min. Motor evoked potentials (MEPs), modified Tarlov score (0-5), serum memantine concentration, and histopathology of the spinal cord were evaluated. RESULTS: Half of all rabbits (21/42) showed spinal protection. Receiver operating characteristic (ROC) curve analysis showed serum level of 4.5 ng/ml as a cutoff value for spinal protection (sensitivity 86%, specificity 62%, area under the curve (AUC) 0.785, P = .002). Sixteen rabbits had serum level ≥ 4.5 ng/ml (group A), with 26 rabbits having < 4.5 ng/ml (group B). Further comparison was done between groups A and B. The mean modified Tarlov score at 6, 24, 48, and 72 h was 4.5 ± 0.9 and 2.4 ± 1.6, in groups A and B, respectively (P < .001). The modified Tarlov score showed positive correlation with serum memantine level (Spearman's rho = 0.618, P = .01). Results of MEP and histopathology were significantly better for group A. CONCLUSIONS: We showed that memantine is protective against SCI at serum levels ≥ 4.5 ng/ml in a rabbit model; thus, it can be a potential adjunct for spinal protection during thoracic/thoracoabdominal aortic surgeries.

Thrombus straddling patent foramen ovale and massive pulmonary embolism.

A thrombus straddling the foramen ovale is rare; and optimal management is controversial. Most of the literature on this topic is available only in the form of case reports. Here, we present a case of 30-year-old female with recent history of fibular fracture and thrombus in transit through patent foramen ovale and massive pulmonary embolism who was successfully managed with pulmonary embolectomy, extraction of serpentine thrombus straddling patent foramen ovale, and closure of patent foramen ovale.

Deceiving spindle cell sarcoma of the heart.

Primary cardiac tumors are rare and when they occur, 75% are benign. Atrial myxomas having a good prognosis compromise 50% of all primary cardiac tumors. Only 25% of the primary cardiac tumors are malignant and 75% of these malignant tumors are sarcomas. Sarcomas often occur in young patients without any predisposing factors and tend to have very poor prognosis. We present an unfortunate case of a young female with high-grade spindle cell sarcoma. She was initially diagnosed to have mitral valve pathology and hypertrophic cardiomyopathy but confirmation of diagnosis was made only after a second operation and patient's demise.

Negative pressure wound therapy induces early wound healing by increased and accelerated expression of vascular endothelial growth factor receptors.

BACKGROUND: Negative pressure wound therapy (NPWT) is commonly used to accelerate wound healing, especially following thoracic surgery; however, the mechanism remains elusive. Given the important role of vasculogenesis in wound healing, we evaluated whether NPWT might accelerate vasculogenesis in the wound area. Toward this end, we investigated the temporal expression of vascular endothelial growth factor receptors (VEGFRs) in an NPWT-wound healing rabbit model. METHODS: Rabbits were divided into an NPWT group and a non-NPWT control group, and tissue samples were collected around wounds made in the skin of each rabbit at five time points: 0, 7, 14, 21, and 28 days after wound creation. Cryopreserved samples were then immunostained and subject to image analysis to evaluate the temporal changes in VEGFR1, VEGFR2, and VEGFR3 expression in the wound-healing process. RESULTS: Results of histological analysis of the temporal changes in VEGFR expression throughout the healing process showed that compared to the control group, VEGFR2 and VEGFR3 were abundantly and rapidly expressed in the NPWT group, and were expressed earlier than VEGFR1. CONCLUSIONS: NPWT promotes the expression of VEGFR2 and VEGFR3, which provides insight into the mechanism by which NPWT accelerates wound healing. Level of Evidence: Not ratable.

A New Suturing Device for Small Arteries.

Endoscope-assisted surgery and robot-assisted surgery are not common in cardiac surgery, particularly coronary artery bypass grafting, because of the complex nature of the procedures. We developed a new suturing device that allows for easy performance of such cardiac surgeries in comparison with conventional suturing methods. A total of 63 rabbits were used in this study. The right carotid artery was bypassed using the same side of the jugular vein under endoscopic guidance. Of these, 48 rabbits were operated on using the new devices and 15 rabbits were operated on using conventional polypropylene sutures. The proximal suturing time was 16.6 ± 5.3 minutes in the group that underwent surgery using the new device (group D) and 22.8 ± 7.6 minutes in the control group (group C; P < 0.05). The distal suture time was 16.3 ± 4.2 minutes in group D and 22.8 ± 6.0 minutes in group C (P < 0.05). The operation time was 113.0 ± 15.8 minutes in group D and 136.7 ± 20.6 minutes in group C (P < 0.05). Graft flow was 19.9 ± 12.8 mL/minute in group D and 12.1 ± 11.3 mL/minute in group C (P < 0.05). Thus, the operation time and the suture time differed significantly between the groups. This device provides advantages in endoscopic surgery compared to the conventional suture method.

Tailor-made heart simulation predicts the effect of cardiac resynchronization therapy in a canine model of heart failure.

Despite extensive studies on clinical indices for the selection of patient candidates for cardiac resynchronization therapy (CRT), approximately 30% of selected patients do not respond to this therapy. Herein, we examined whether CRT simulations based on individualized realistic three-dimensional heart models can predict the therapeutic effect of CRT in a canine model of heart failure with left bundle branch block. In four canine models of failing heart with dyssynchrony, individualized three-dimensional heart models reproducing the electromechanical activity of each animal were created based on the computer tomographic images. CRT simulations were performed for 25 patterns of three ventricular pacing lead positions. Lead positions producing the best and the worst therapeutic effects were selected in each model. The validity of predictions was tested in acute experiments in which hearts were paced from the sites identified by simulations. We found significant correlations between the experimentally observed improvement in ejection fraction (EF) and the predicted improvements in ejection fraction (P<0.01) or the maximum value of the derivative of left ventricular pressure (P<0.01). The optimal lead positions produced better outcomes compared with the worst positioning in all dogs studied, although there were significant variations in responses. Variations in ventricular wall thickness among the dogs may have contributed to these responses. Thus CRT simulations using the individualized three-dimensional heart models can predict acute hemodynamic improvement, and help determine the optimal positions of the pacing lead.

Novel Anastomotic Device for Distal Coronary Anastomosis: Preclinical Results From Swine Off-Pump Coronary Artery Bypass Model.

PURPOSE: We evaluated the safety and feasibility of a new anastomotic device that simplifies coronary distal anastomosis during minimally invasive and robotically assisted coronary artery bypass graft surgery (CABG). DESCRIPTION: Fourteen miniature pigs underwent off-pump CABG using bilateral internal thoracic arteries (ITA), namely, left ITA to left anterior descending artery and right ITA to right coronary artery. The device was used for distal anastomosis in a device group (n = 11), and conventional 7-0 polypropylene suture in a control group (n = 3). Graft flow was measured intraoperatively. One-month, 3-month, and 6-month postoperative angiography evaluations were done. Histopathologic examination of the anastomosis was also done. EVALUATION: Baseline and intraoperative characteristics were similar in the two groups. There was no difference of anastomotic time between groups (p = 0.59). Graft flows were also similar (p = 0.55), with good diastolic pattern in both groups. Angiography demonstrated FitzGibbon A patency in all anastomoses of both groups at each evaluation period. Histopathologic examination showed nonspecific inflammatory changes in the device group. CONCLUSIONS: The safety and feasibility of this anastomotic device for distal coronary anastomosis were shown in the swine model.

Spinal cord injury following thoracic and thoracoabdominal aortic repairs.

OBJECTIVE: To discuss the currently available approaches to prevent spinal cord injury during thoracic and thoracoabdominal aortic repairs. METHODS: We carried out a PubMed search up to 2013 using the Medical Subject Headings: "aortic aneurysm/surgery" and "spinal cord ischemia"; "aortic aneurysm, thoracic/surgery" and "spinal cord ischemia"; "aneurysm/surgery" and "spinal cord ischemia/cerebrospinal fluid"; "aortic aneurysm/surgery" and "paraplegia". All 190 original articles satisfying our inclusion criteria were analyzed for incidence, predictors, and other pertinent variables related to spinal cord injury, and we compared the results in recent publications with those in earlier reports. RESULTS: The mean age of the 38,491 patients was 65.3 ± 4.9 years. The overall incidence of paraplegia and/or paraparesis was 7.1% ± 6.1% (range 0%-32%). The incidence of spinal cord injury before 2000, from 2001 to 2007, and 2008-2013 was 9.0% ± 6.7%, 7.0% ± 6.1%, and 5.9% ± 5.2%, respectively (p = 0.019). Various predictors of spinal cord injury were identified, extent of disease being the most common. Modification of surgical techniques, use of adjuncts, and better understanding of spinal cord perfusion physiology were attributed to the decrease in postoperative spinal cord injury in recent years. CONCLUSIONS: Spinal cord injury after thoracic and thoracoabdominal aortic repair poses a real challenge to cardiovascular surgeons. However, with evolving surgical strategies, identification of predictors, and use of various adjuncts over the years, the incidence of spinal cord injury after thoracic/thoracoabdominal aortic repair has declined. Embracing a multimodality approach offers a good insight into combating this grave complication.

Paraplegia prevention by oral pretreatment with memantine in a rabbit model.

OBJECTIVE: To evaluate the role of memantine (N-methyl-d-aspartate receptor antagonist) pretreatment for the prevention of spinal cord ischemia after infrarenal aortic clamping in a rabbit model. METHODS: Thirty New Zealand White rabbits were divided into 5 different groups of 6 rabbits. Groups 60-7 and 60-5 received oral memantine 60 mg once a day for 7 and 5 days, respectively, and groups 30-5 and 30-3 received oral memantine 30 mg once a day for 5 and 3 days, respectively, all before surgery. Group C (control) received normal feeds without memantine. A paraplegic model was created by clamping both the aorta and the inferior vena cava infrarenally and just proximal to their bifurcations for 45 minutes. The modified Tarlov score, motor evoked potential (MEP), serum memantine concentration, and histopathology of the spinal cord were evaluated. RESULTS: The mean modified Tarlov scores were 4.2±1.3, 4.3±1.0, 4.2±1.3, 4.3±1.2, and 0.8±1.6 in groups 60-7, 60-5, 30-5, 30-3, and C, respectively at 6, 24, 48, and 72 hours (P<.009 for individual groups vs control). Percentage amplitude loss of MEP by the end of surgery was 29.5%±46.3%, 11.9%±28.0%, 30.0%±46.8%, 16.7%±40.8%, and 81.8%±40.3% for the 5 groups, respectively (P=.049). After declamping, MEP reappeared in 83%, 100%, 83%, 83%, and 33% of cases in the 5 groups, respectively (P=.073). The serum memantine level was similar in the 4 memantine groups. Spinal cords were normal in most of the rabbits in groups 60-7, 60-5, 30-5, and 30-3, but severely ischemic in most of the rabbits in group C (P=.041). CONCLUSIONS: Oral memantine pretreatment is protective against spinal cord ischemia, and can be an additional strategy for the prevention of paraplegia during thoracoabdominal aortic surgeries.

Development of a suturing device for anastomosis for small caliber arteries.

The use of minimally invasive and robotic operations has been increasing for coronary artery bypass surgery; however, no suturing devices have been universally adopted for use in these procedures. We developed a new suturing device that enables omission of manual ligation after a running suture. Twenty-two rabbits were used in this study. In 22 rabbits, the right carotid artery was bypassed using an autologous jugular vein graft. Half of the animals were operated on using the new device and the other half using conventional suturing methods. Postoperative evaluations were performed at 1, 3, and 6 months. Suturing time was 15.6 ± 2.4 min in the device group and 16.6 ± 4.4 min in the control group (p = 0.34). Graft patency and blood flow measurements were not significantly different between the two groups. Histopathological examination of the anastomotic site showed common inflammatory responses in both groups. No particular histopathological change was seen related to the device. In conclusion, the safety of the new suturing device was confirmed, and its efficacy was equal to that of the conventional suturing technique.

Aortic valve replacement for aortic stenosis caused by alkaptonuria.

We report a case of aortic stenosis associated with ochronosis in a 70-year-old man who underwent biologic aortic valve replacement. Intraoperative findings included ochronosis of a severely calcified pigmented aortic valve along with pigmentation of the intima of the aorta.

Nepalese pharmacy students' perceptions regarding mental disorders and pharmacy education.

OBJECTIVE: To determine Nepalese pharmacy students' perceptions of whether mental disorders impact performance in pharmacy school. METHOD: All first- and third-year undergraduate pharmacy students (n=226) in Nepal were invited to complete a modified version of the Mental Illness Performance Scale. RESULTS: Among the 200 respondents (response rate 88.5%), 14% reported that they had a mental disorder. The majority (92%) of third-year students agreed or strongly agreed that depression would interfere with a student's academic performance. Almost half of first-year students agreed or strongly agreed that alcohol or drug abuse would be grounds for both rejecting an applicant from pharmacy school (49%) and dismissal of a student from pharmacy school (46%). CONCLUSIONS: Students perceived a high level of academic impairment associated with mental disorders, but the majority did not perceive that mental disorders were grounds for dismissal from or rejection of entry to pharmacy school. Students' attitudes may discourage them from seeking help or providing mental health support to others.