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.

Prevalence of Significant Tricuspid Regurgitation in Patients Planned for Mitral Valve Surgery in a Tertiary Center of Nepal

Background Tricuspid regurgitation is frequently present in patients with mitral valve disease and most of this tricuspid regurgitation present are significant. Objective To find out the prevalence of tricuspid regurgitation in adult patients present in our hospital who are planned for isolated mitral valve surgery for mitral stenosis, mitral regurgitation or both. Patients with moderate and severe tricuspid regurgitation were considered as significant. Method This was the retrospective cross-sectional study performed at Shahid Gangalal National Heart Center of Nepal. All cardiac surgical patients scheduled for isolated mitral valve surgery during the 3 years' period from 2017 to 2020 were enrolled in the study and presence or absence of significant tricuspid regurgitation were recorded and analysed. Result Out of total patients 65% (663) of the cases with mitral valve pathology had significant tricuspid regurgitation. Out of the total mitral stenosis cases 70% were associated with significant tricuspid regurgitation, 62.6% of the cases of mitral regurgitation had significant tricuspid regurgitation and 64.8% of patients with combined mitral stenosis and regurgitation were associated with significant tricuspid regurgitation. Conclusion Significant tricuspid regurgitation is present in most of the cases with isolated mitral valve pathology. So routine tricuspid valve evaluation and repair if needed during mitral valve surgeries is recommended.

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.

Sternal Fracture Fixation with a Steel Wire: The New “Timala” Technique

Purpose Traumatic sternal fractures are rare but quite disabling injuries. Timely fixation of sternal fractures reduces pain and prevents respiratory complications. However, the fixation technique should be simple, effective, and readily available in local circumstances. Methods From January 2014 to March 2020, seven patients with sternal fracture/ dislocation underwent steel wire fixation with the new “Timala” technique. In this technique, adjacent ribs are anchored with two steel wires to form an “X” in front of the fractured segment of the sternum. Patients were followed up clinically and radiologically. Results Six of the patients were men and one was a female. Five of them had injuries due to falls and two were injured in road traffic accidents. Their age ranged from 18 years to 76 years, with a median age of 41 years. All seven patients experienced immediate recovery from pain and showed evidence of fracture healing on postoperative chest X-rays and clinical examinations. Conclusions Anchoring ribs to fix the sternum with steel wire is a safe, effective, easily available, and reproducible method to fix sternal fractures or dislocations.

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.

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.

Clinical and epidemiological features of COVID-19 deaths in Nepal

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has taken more than 1 million lives globally. This study, based on the official media releases of the Government of Nepal, analyses the clinical and epidemiological features of the individuals who died as a result of COVID-19 in Nepal from 23 January to 10 August 2020. We found that nearly half of the deaths were among people less than 50 years of age and being female increased the risk of death. The majority of deaths were associated with co-morbidities, the most common being cardiovascular diseases and diabetes followed by respiratory diseases. With the approaching festive season and relaxed lockdown, both government and citizens need to be more cautious about the severity of COVID-19 and take appropriate action.

COVID-19: the current situation in Nepal

The recent global pandemic of novel coronavirus disease 2019 (COVID-19) is increasingly alarming. As of 21 June 2020, there are more than 8.7 million cases worldwide, with 460 000 deaths. Nepal is not an exception to COVID-19 and is currently facing a challenge to prevent the spread of infection. The analysis of the detected cases, severity and outcomes of the cases within a country is important to have a clear picture of where the pandemic is heading and what measures should be taken to curb the infection before it becomes uncontrollable. We collected data regarding all the cases, recoveries and deaths attributed to COVID-19 in Nepal starting from the first case on 23 January to 21 June 2020. At present, COVID-19 has spread all over Nepal, with a rapid increase in the number of new cases and deaths, which is alarming in a low-income country with an inadequate healthcare system like Nepal. Although the government implemented early school closure and lockdown, the management to contain COVID-19 does not appear to be adequate. Understanding the current situation regarding COVID-19 in Nepal is important for providing a direction towards proper management of the disease.

Multi-drug Resistant and Extended Spectrum β-lactamase Producing Salmonella Species Isolated from Fresh Chicken Liver Samples

Background Ductus arteriosus is a vascular structure which connects the roof of main pulmonary artery near the origin of the left branch pulmonary artery to the proximal descending aorta. Patent ductus arteriosus (PDA) closure is indicated for any patient who is symptomatic from left to right shunting. Objective To investigate the hospital outcomes of surgical closure of patent ductus arteriosus over last 19 years starting from the very first case of our center. Method This is a retrospective analysis of all patent ductus arteriosus treated surgically from August 2001 to July 2019. Patients who underwent isolated surgical closure of patent ductus arteriosus were included. Data have been presented in three different eras (Era 1: 2001-2007, Era 2: 2008-2013, and Era 3: 2014-2019) to see the trend of evolution of this surgery. Result A total of 901 patients aged 8.67±8.76 years under went patent ductus arteriosus surgical closure over last 19 years. Patients in the initial era 2001-2007 were significantly older compared with other 2 eras (p=0.000). Males accounted for 35.5% of all cases. Twenty percent had severe pulmonary artery hypertension.Duration of mechanical ventilation was 3.57±9.64 hours with ICU stay of 1.55±1.53 days, and hospital stay of 3.9±2.3 days. Overall in hospital mortality was 0.8%; for isolated patent ductus arteriosus diagnosis, mortality was 0.2%. Chylothorax was noted in 0.4%. Conclusion This is the first report to analyze surgical outcomes of patent ductus arteriosus ligation in our center. We have discussed the evolution of patent ductus arteriosus surgery in our center, and have shown favorable outcomes in terms of morbidity and mortality.

Predictors of in-hospital mortality following mitral or double valve replacement for rheumatic heart disease

Backgrounds and Aims: Factors affecting outcome of mitral valve replacement in rheumatic population of Nepal is unknown. The aim of this study was to identify the predictors of in-hospital mortality in patients undergoing mitral or double valve replacement in Nepal.Methods: A retrospective observational study was designed to evaluate the outcome of patients who underwent mitral valve replacement with or without concomitant other valvular surgery during a period of one year in a tertiary care cardiac centre in Nepal. Data were analysed to find the significant predictors of in-hospital mortality.Results: A total of 411 patients fulfilled the inclusion criteria. The overall in-hospital mortality was 4.1% (95% CI 2.18-6.02). A cutoff value for higher mortality obtained using ROC curve for age was 37.5 years; and for duration of mechanical ventilation was 8.5 hours. Multivariate logistic regression model identified increasing age (>37.5 years), OR 2.05 (95% CI 0.77-5.45), p=0.001; NYHA Class III and IV, OR 15.18 (95%CI 0.9-54.53), p<0.001; presence of left atrial thrombus, OR 4.96 (95% CI 1.49-16.43), p=0.003; tricuspid regurgitation grade III and IV, OR 2.62 (95% CI 0.95-7.24), p=0.004; re-exploration for bleeding, OR 8.62 (95% CI 1.60-46.32), p=0.03; left ventricular ejection fraction (≤40%), OR 8.22 (95% CI 2.62-25.72), p=0.001; inotrope score >20, OR 9.90 (95% CI 3.48-28.15), p<0.001; duration of mechanical ventilation >8.5 hours, OR 22.96 (95% CI 5.15-52.10), p<0.001; and stay in the intensive care unit > 2 days, OR 1.31 (95% CI 0.49-3.46), p<0.001 as predictors of mortality.Conclusion: Age, NYHA Class, severe tricuspid regurgitation, presence of left atrial clot, re-exploration for bleeding, decreasing left ventricular ejection fraction, high inotrope score, longer duration of mechanical ventilation, and longer stay in the intensive care unit were identified as the independent predictors of in-hospital mortality.  Nepalese Heart Journal 2016; 13(2): 19-24

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.

Fontan Failure and Thrombosis of Total Cavo-Pulmonary Connection Conduit

The immediate postoperative period of Fontan operation is frequently complicated by hemodynamic instability, sometimes requiring fenestration of the conduit. Thrombosis of total cavo-pulmonary connection conduit warrants early intervention to prevent systemic and pulmonary embolism. We report a case of Fontan failure requiring fenestration; which was further complicated by thrombosis of total cavo-pulmonary connection conduit and managed with anticoagulants.

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.

Fontan Failure and Thrombosis of Total Cavo-Pulmonary Connection Conduit

The immediate postoperative period of Fontan operation is frequently complicated by hemodynamic instability, sometimes requiring fenestration of the conduit. Thrombosis of total cavo-pulmonary connection conduit warrants early intervention to prevent systemic and pulmonary embolism. We report a case of Fontan failure requiring fenestration; which was further complicated by thrombosis of total cavo-pulmonary connection conduit and managed with anticoagulants.  Keywords: congenital heart disease; fontan procedure; thrombosis.