Minimally invasive versus conventional sternotomy for Mitral valve repair: protocol for a multicentre randomised controlled trial (UK Mini Mitral)

INTRODUCTION

Numbers of patients undergoing mitral valve repair (MVr) surgery for severe mitral regurgitation have grown and will continue to rise. MVr is routinely performed via median sternotomy; however, there is a move towards less invasive surgical approaches.There is debate within the clinical and National Health Service (NHS) commissioning community about widespread adoption of minimally invasive MVr surgery in the absence of robust research evidence; implementation requires investment in staff and infrastructure.The UK Mini Mitral trial will provide definitive evidence comparing patient, NHS and clinical outcomes in adult patients undergoing MVr surgery. It will establish the best surgical approach for MVr, setting a standard against which emerging percutaneous techniques can be measured. Findings will inform optimisation of cost-effective practice.

METHODS AND ANALYSIS

UK Mini Mitral is a multicentre, expertise based randomised controlled trial of minimally invasive thoracoscopically guided right minithoracotomy versus conventional sternotomy for MVr. The trial is taking place in NHS cardiothoracic centres in the UK with established minimally invasive mitral valve surgery programmes. In each centre, consenting and eligible patients are randomised to receive surgery performed by consultant surgeons who meet protocol-defined surgical expertise criteria. Patients are followed for 1 year, and consent to longer term follow-up.Primary outcome is physical functioning 12 weeks following surgery, measured by change in Short Form Health Survey (SF-36v2) physical functioning scale. Early and 1 year echo data will be reported by a core laboratory. Estimates of key clinical and health economic outcomes will be reported up to 5 years.The primary economic outcome is cost effectiveness, measured as incremental cost per quality-adjusted life year gained over 52 weeks following index surgery.

ETHICS AND DISSEMINATION

A favourable opinion was given by Wales REC 6 (16/WA/0156). Trial findings will be disseminated to patients, clinicians, commissioning groups and through peer reviewed publication.

TRIAL REGISTRATION NUMBER

ISRCTN13930454.

Outcomes in minimally invasive double valve surgery

OBJECTIVE

To review current literature evidence on outcomes of minimally invasive double valve surgeries (MIS).

METHODS

A comprehensive electronic literature search was done from inception to 20th June 2020 identifying articles that discussed outcomes of minimally invasive approach in double valve surgeries either as a solo cohort or as comparative to conventional sternotomies. No limit was placed on time and place of publication and the evidence has been summarized in narrative manner within the manuscript.

RESULTS

Majority of current literature reported similar perioperative and clinical outcomes between MIS and conventional median sternotomy; except that MIS has better cosmetic effects and pain control. Nevertheless, minimal invasive techniques are associated with longer cardiopulmonary bypass and aortic cross-clamp times which may have impact on the reported outcomes and overall morbidity and mortality rates.

CONCLUSION

Minimally invasive double valve surgery continues to develop, but scarcity in the literature suggests uptake is slow, possibly due to the learning curve associated with MIS. Many outcomes appear to be comparable to conventional sternotomy. There is need for larger, multi-center, and randomized trial to fully evaluate and establish the early, mid- and long-term morbidity and mortality rates associated with both techniques.

Endoscopic Tricuspid Valve Surgery is a Safe and Effective Option

OBJECTIVE

Isolated tricuspid surgery through median sternotomy can be associated with a high morbidity and mortality. Reports of minimally invasive isolated tricuspid valve operations are rare, but the outcomes are encouraging. We present our experience of endoscopic isolated tricuspid valve surgery.

METHODS

In our institution, 452 patients underwent endoscopic minimal access cardiac surgery between August 2008 and December 2018. A total of 90 patients underwent tricuspid valve surgery whether isolated or with other cardiac procedure. We further selected patients who had isolated tricuspid valve surgery (n = 24). Of these patients, 13 (54%) had more than one previous sternotomy.

RESULTS

Tricuspid repair was performed in 18 patients (75%) with the remaining 6 (25%) having bioprosthetic tricuspid replacement. Three (12.5%) were performed with a beating heart, the remaining with endoaortic clamping and cardioplegia. There were no conversions to sternotomy. None of the patients had reoperation for bleeding, tamponade, or valve issues. Three patients (12.5%) required blood transfusion, 3 patients (12.5%) required renal dialysis, and 7 patients (29%) had respiratory complications such as chest infection, requiring continuous positive airway pressure (CPAP) with 2 being re-intubated. One patient (4.1%) died within 30 days from chest sepsis leading to multi-organ failure. Mean hospital stay was 11.1 ± 8.9 days (median of 8). All patients had mild or less regurgitation on follow-up echo at 6 months.

CONCLUSIONS

Isolated tricuspid valve surgery can be performed through an endoscopic minimally access approach, with good results. It appears to provide better results than a sternotomy approach. A high repair rate can be achieved, and the procedure is particularly valuable in redo-surgery with low mortality and morbidity compared to historical sternotomy case series.

Urinary 8-hydroxydeoxyguanosine as a marker of oxidative stress induced genetic toxicity in oral cancer patients

CONTEXT

Recently, non-communicable diseases have snatched the lead from infectious diseases in causing mortality. Of these, oral cancer accounts for a significant proportion of deaths. Every year in India significant percentage of newly diagnosed malignancy is oral cancer attributed to various reasons.

AIMS

The aim of this study was to assess the extent of oxidative stress and its effect on modification of DNA by urinary nucleoside 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in oral cancer subjects. To see the relationship between the nucleoside 8-OHdG and antioxidant capacity ferric reducing ability plasma (FRAP) in oral cancer subjects.

SETTINGS AND DESIGN

Case-control study included three groups with 60 volunteers, who were divided into 30 controls, and equal number of clinically diagnosed oral cancer male patients: (Subdivided into newly diagnosed [n = 15] and 1-year treatment follow-up oral cancer subjects [n = 15]).

MATERIALS AND METHODS

A random urine sample was used for analysis of 8-OHdG concentration. Serum triglycerides, lipid peroxidation, protein thiols, and FRAP assay were performed by spectrophotometric technique.

STATISTICAL ANALYSIS USED

Student's t-test and one-way analysis of variance were performed for group comparison and Pearson's correlation analysis were used. A P < 0.05 was considered the optimum level of significance.

RESULTS

The urinary 8-OHdG and serum malondialdehyde levels were significantly elevated in newly diagnosed oral cancer subjects in their 1-year treatment compared to the control group (P < 0.05). A significant correlation was observed between urinary 8-OHdG and FRAP in both groups of oral cancer subjects.

CONCLUSIONS

Urinary 8-OHdG can be a useful diagnostic marker of oxidative DNA damage in oral cancer subjects.

Bridging to lung transplantation for severe pulmonary hypertension using dual central Novalung lung assist devices

This case describes the technique of using dual Novalungs (a pumpless extracorporeal system) to bridge a patient with idiopathic pulmonary hypertension to bilateral lung transplantation. A 41-year old lady with idiopathic pulmonary hypertension (with a possible veno-occlusive element) presented with symptoms of end-stage heart and lung failure. This was refractory to medical management with iloprost, sildenafil and bosentan. The patient was placed on the urgent waiting list for lung transplantation and central pulmonary artery to left atrial Novalung insertion was performed. Local anaesthetic was given before performing peripheral cardiopulmonary bypass due to the high risk of cardiac arrest. Two days later, donor organs became available and the patient was taken for double-lung transplantation. The pulmonary artery cannula was removed leaving a large defect. This was then closed using a bovine pericardial patch. Due to the damaged right superior pulmonary vein from Novalung cannulation, cardioplegia was given to facilitate an open atrial anastomosis. After 13 days in the intensive therapy unit, she was transferred to the ward. There were no further complications and she has been discharged home.

Association of inflammatory sialoproteins, lipid peroxides and serum magnesium levels with cardiometabolic risk factors in obese children of South Indian population

The Incidence of childhood obesity and metabolic syndrome is increasing even in rural and semi-urban regions of India. Adipose tissue mass secretes several inflammatory proteins, which could potentially alter the metabolic processes, leading to several complications at the later stages of life. With limited studies on protein bound sialic acid (PBSA) as a marker of oxidative stress mediated inflammation in obese children, this study was aimed to assess and correlate PBSA with lipid peroxidation and other cardiometabolic risk factors like Insulin Resistance (IR), serum magnesium, and high sensitive C reactive Protein (hsCRP) levels in order to provide an insight into the degree of systemic inflammation and oxidative stress. This study included 62 obese children (≥95% percentile of the CDC chart) and 60 non obese controls. This study documents significant higher levels of PBSA, IR, Malondialdehyde (MDA), hsCRP and uric acid in obese children (p<0.001). PBSA was associated with IR, hsCRP, uric acid, hypomagnesaemia. Higher degrees of oxidative stress, Insulin resistance and low serum magnesium levels were noted in obese children. PBSA and hsCRP levels were elevated and were associated with Insulin resistance in obese children of South Indian population.

A Comparative Study of Serum Uric Acid levels and Lipid Ratios in Coronary Artery Disease Patients

INTRODUCTION

Coronary Artery Disease (CAD) appears to be common in the Indian population of different geographical origins, religions and languages. Measurement of lipid fractions and ratios are widely recommended for risk assessment. A few studies have shown that serum uric acid plays a role in the development of cardiovascular morbidity. Very few reports are cited linking serum uric acid with the lipid fraction in CAD.

OBJECTIVES

To find the significance of non-HDL cholesterol, LDL-c/HDL-c ratio, TC/HDL ratio and serum uric acid level in CAD patients.

SUBJECTS AND METHODOLOGY

In this study, we included fifty CAD patients as subjects and an equal number of controls. Both subjects and controls were assessed for anthropometric, physiological and biochemical parameters.

RESULTS

The present study showed significant increased levels of total cholesterol (p=0.002), TAGs (p<0.001), HDL (p=0.005), LDL (p<0.006) and non-HDL cholesterol (p<0.001). LDL-c/HDL-c ratio (p<0.001) and TC/HDL ratio (p<0.001) in CAD patients (subjects) were also significant when compared to controls. Uric acid level in CAD patients was increased (p<0.001).

CONCLUSION

Serum Uric Acid, TC/HDL and LDL/HDL ratios could be regarded as objective markers, in association with existing atherogenic dyslipidemia in patients with CAD.

Identification of mistakes and their correction by a small group discussion as a revision exercise at the end of a teaching module in biochemistry

BACKGROUND

Graduate medical students often get less opportunity for clarifying their doubts and to reinforce their concepts after lecture classes. The Medical Council of India (MCI) encourages group discussions among students. We evaluated the effect of identifying mistakes in a given set of wrong statements and their correction by a small group discussion by graduate medical students as a revision exercise.

METHODS

At the end of a module, a pre-test consisting of multiple-choice questions (MCQs) was conducted. Later, a set of incorrect statements related to the topic was given to the students and they were asked to identify the mistakes and correct them in a small group discussion. The effects on low, medium and high achievers were evaluated by a post-test and delayed post-tests with the same set of MCQs.

RESULTS

The mean post-test marks were significantly higher among all the three groups compared to the pre-test marks. The gain from the small group discussion was equal among low, medium and high achievers. The gain from the exercise was retained among low, medium and high achievers after 15 days.

CONCLUSION

Identification of mistakes in statements and their correction by a small group discussion is an effective, but unconventional revision exercise in biochemistry.

Serum lipid peroxides and magnesium levels following three months of treatment with pioglitazone in patients with type-2 diabetes mellitus

BACKGROUND

Higher levels of lipid peroxidation and hypomagnesaemia are frequently associated with Type 2 Diabetes mellitus (T2DM). Addressing these issues would definitely help us in preventing or prolonging the onset of pathogenesis of micro and macrovascular complications. Pioglitazone is used as a trusted insulin sensitizer and an adjuvant to the conventional oral hypoglycemic agents. This study was planned to explore the effects of pioglitazone on oxidative stress, serum magnesium, blood pressure, hepato-biliary and renal systems in addition to its effects on glycemic control.

METHODS

Sixty-three T2DM cases, who were started on pioglitazone were included in this study. All the physiological and biochemical parameters were estimated prior to and following three months of therapy with pioglitazone.

RESULTS

There was significant improvement in the glycemic control, serum magnesium and MDA levels with p values of 0.000, 0.023 and 0.000 respectively. Pioglitazone did not have any significant effects on the serum lipids and blood pressure in T2DM cases following three months of treatment. We did not observe any pronounced changes in hepato-biliary enzymes, serum urea and creatinine levels reaffirming safety of pioglitazone in T2DM.

CONCLUSION

Three-month duration of treatment with Pioglitazone in T2DM cases helps in alleviating the levels of lipid peroxides, besides being associated with improved serum magnesium status and glycemic control.

Status of serum magnesium in type 2 diabetes mellitus with particular reference to serum triacylglycerol levels

Magnesium (Mg) is the fourth most abundant cation in the body and the second most common intracellular cation. The association between hypomagnesemia and insulin resistance (IR) in diabetes mellitus has been documented earlier. However, we wanted to study whether the extracellular status of magnesium (Mg) could be a biochemical mediator between hypertriacylglycerolemia and diabetes mellitus.

AIMS

To find out the probable association among HbA1c, triacylglycerol (TG) and magnesium levels - a predictor of vascular complications in T(2)DM.

MATERIALS AND METHODS

Thirty patients who had attended the diabetic clinics during the period of this study were included. All the samples were analysed for glucose, TG, Mg, and HbA1c. For statistical analysis, SPSS 17 package was used.

RESULTS

Serum TG (236.67*, 195.06) and HbA1C (9.97*, 8.57) levels were independently compared between the two groups and were significantly high in group A subjects (Mg<1.2mg/dl) as compared to group B subjects (Mg>1.2mg/dl) (*p-value<0.05), respectively.

DISCUSSION AND CONCLUSION

Hypertriacylglycerolemia was pronounced in type 2 diabetes mellitus patients with accompanying hypomagnesemia. This compared well with that of the glycemic control. Low Mg levels, high TG levels in association with enhanced HbA1c levels could thus serve as a reliable biochemical indicator of insulin status and action without resorting to the usage of criteria for insulin sensitivity and resistance.

Successful Graft Patency After Factor VIIa Use for Bleeding in Coronary Artery Surgery

There is a growing literature regarding the use of recombinant activated factor VII (rFVIIa) (NovoSeven, NovoNordisk, Copenhagen, Denmark) to control refractory hemorrhage after cardiopulmonary bypass in cardiac surgery. This supporting evidence is mostly documented as case reports on patients, of which only six involve coronary artery grafting. We present our experience of a patient undergoing coronary artery bypass grafting, who suffered an anaphylactic reaction to protamine preventing safe reversal of systemic heparinization. Subsequent management of postoperative bleeding was successfully achieved only after rFVIIa administration.

How safe is it to train residents to perform off-pump coronary artery bypass surgery?

BACKGROUND

The technique of off-pump coronary artery bypass graft (OPCABG) surgery differs considerably from on-pump CABG. This study investigates the impact of surgical training on clinical outcome in patients undergoing OPCABG.

METHODS

All 251 OPCABG cases performed by one service over an 18-month period were analyzed. The 83 operations (33%) performed by two trainees under supervision were compared with the 168 operations (67%) performed by an experienced consultant surgeon. Patient and disease characteristics, intraoperative and postoperative data, morbidity and mortality were analyzed using univariate and multivariate analysis. Data were extracted from a prospective database.

RESULTS

Patients operated on by the consultant were more likely to have had unstable angina (p = 0.003, odds ratio [OR] = 3.5), impaired left ventricular function (ejection fraction < 0.3; p = 0.005, OR = 2.4), or previous cardiac surgery (p = 0.03). They were more likely to receive three or more grafts (p = 0.017, OR = 2.0). Operative mortality was 2.4% (consultant) and 0% (trainees; p = 0.31). Postoperative morbidity, such as reoperation for bleeding (consultant 3% versus trainees 1.2%), stroke (0.6% versus 1.2%), and hemofiltration (3.6% versus 0%) was similar between the two patient groups. Stay in the intensive care unit was not significantly different in the two groups.

CONCLUSIONS

In our experience, trainee surgeons are less likely to operate on patients with unstable angina or cardiac dysfunction. Operative morbidity and mortality are, however, similar in patients operated on by either an experienced consultant surgeon or trainees. We believe OPCABG can be taught safely to trainees under supervision.

Effects of cell saver autologous blood transfusion on blood loss and homologous blood transfusion requirements in patients undergoing cardiac surgery on- versus off-cardiopulmonary bypass: a randomised trial

OBJECTIVE

Off-pump CABG is potentially associated with reduced intraoperative blood loss and homologous blood transfusion in comparison to on-pump CABG. In this randomised controlled study we investigated the effects of autologous cell saver blood transfusion on blood loss and homologous blood transfusion requirements in patients undergoing CABG on- versus off-CPB.

METHODS

Eighty patients were randomised into one of four groups: (A) on-CPB with cell saver blood transfusion (CSBT), (B) on-CPB without CSBT, (C) off-pump with CSBT and (D) off-pump without CSBT. Volume of intraoperative autologous blood transfusion, postoperative mediastinal blood loss and homologous blood transfusion requirements were measured. Homologous blood was transfused when haemoglobin concentration fell below 8 g/dl postoperatively. Pre- and postoperatively prothrombin time and partial thromboplastin time were measured.

RESULTS

Preoperative patient characteristics were well matched among the four groups. The amount of salvaged mediastinal blood available for autologous transfusion was significantly higher in the on-pump group (A) compared to the off-CPB group (C) (433+/-155 ml vs 271+/-144 ml, P=0.001). Volume of homologous blood transfusion was significantly higher in group B vs groups A, C and D (595+/-438 ml vs 179+/-214, 141+/-183 and 230+/-240 ml, respectively, P<0.005). The cell saver groups (A and C) received significantly less homologous blood than the groups without cell saver (160+/-197 ml vs 413+/-394 ml, respectively, P<0.005). Patients undergoing off-CPB surgery received significantly less homologous blood than those undergoing on-CPB CABG irrespective of cell saver blood transfusion (184+/-214 ml vs 382+/-397 ml, P<0.05). Postoperative blood loss was similar in the four groups (842+/-276, 1023+/-291, 869+/-286 and 903+/-315 ml in groups A to D, respectively, P>0.05). Clotting test results revealed no significant difference between the groups. There was no significant difference in postoperative morbidity between groups.

CONCLUSION

Off-pump CABG is associated with significant reduction in intraoperative mediastinal blood loss and homologous transfusion requirements. Autologous transfusion of salvaged washed mediastinal blood reduced homologous transfusion significantly in the on-CPB group. Cell saver caused no significant adverse impact on coagulation parameters in on- or off-CPB CABG. Postoperative morbidity and blood loss were not affected by the use of CPB or autologous blood transfusion. We recommend the use of autologous blood transfusion in both on- and off-pump CABG surgery.

Complex off-pump coronary artery bypass surgery can be safely taught to cardiothoracic trainees

OBJECTIVES

Off-pump coronary revascularisation is demanding technically as the surgeon is faced with a beating heart and not a bloodless field. The potential clinical advantages of off-pump coronary revascularisation have made this procedure an essential part of a cardiothoracic training program. The aim of this study is to investigate the impact of teaching trainees complex off-pump coronary artery surgery (arterial grafting, 'Y' grafts, sequential grafting and minimally invasive direct coronary artery bypass) on clinical outcomes.

METHODS

All 323 off-pump coronary revascularisation cases performed by one service over a 24-month period were analysed. The 125 (39%) operations performed by two trainees with previous exposure in on-pump surgery were compared with the 198 (61%) performed by an experienced consultant surgeon. Patient and disease characteristics, intra- and post-operative data, morbidity and mortality were analysed using uni- and multivariate analysis.

RESULTS

The trainees performed 51% of the MIDCABs, 36% of the 'Y' grafts and 27.5% of the sequential grafts. The internal thoracic artery was used in 96% of the cases, radial artery in 49% and bilateral internal thoracic arteries in 11% equally distributed between trainees and consultant. The average number of grafts per case was 3.7 for the consultant and 3.3 for the trainees. Patients operated by the consultants were more likely to have unstable angina (P=0.008), ejection fraction <30% (P=0.01) previous cardiac surgery (P=0.027) and more likely to receive over 4 grafts (P=0.01). Operative mortality was 1.5% for the consultant and 0 for the trainees (P=0.17). Post-operative morbidity, such as re-operation for bleeding (consultant 1% vs. trainee 0.8%), stroke (0.5% vs. 0.8%), haemofiltration (3.5% vs. 0.8%) was similar between the two groups. Hospital stay was also similar.

CONCLUSIONS

The results of this study suggest that trainees under supervision perform complex off-pump coronary artery surgery safely with low rate of mortality and complications. These findings are in agreement with previous literature reports. Trainees should be allowed to operate on sufficient number of patients undergoing off-pump surgery according to their skills and abilities. Patients should be reassured that safety is not compromised by the presence of a trainee as a primary surgeon.