Use of transoesophageal echocardiography in management of penetrating cardiac injury.

A 53-year-old man who sustained an accidental cardiac nail gun injury presented to us in haemodynamically stable condition. He had an urgent plain radiograph film and contrast CT scan to determine the exact position of the nail. CT showed the nail to be in juxtacardiac position but did not give any conclusive information about breach of pericardium or myocardial wall. An intra-operative transoesophageal echocardiography was done to determine the exact position of the nail. It clearly delineated the position of the nail and guided us towards median sternotomy and removal of nail under direct vision safely.

Effect of experimental cardiopulmonary bypass on systemic and transcardiac thromboxane B2 levels.

Systemic and cardiac metabolism of thromboxane was studied in a canine model (n = 13) of standard cardiopulmonary bypass and surgical cardioplegia. Sterile techniques were applied and no donor blood was used. Systemic samples (thoracic aorta) and transcardiac gradients (coronary sinus - aortic root) were obtained (1) 5 minutes after cannulation, (2) 20 minutes after the onset of partial bypass, (3) 5 seconds after the first administration of cardioplegic solution (CP-1), and (4) 5 seconds after the second administration of cardioplegic solution (CP-2). Cardioplegic doses were administered 30 minutes apart and consisted of 500 ml of hypothermic (8 degrees C), hyperkalemic (25 mEq potassium chloride) solution infused into the aortic root at 60 to 70 mm Hg. Thromboxane B2 was determined by a double-antibody radioimmunoassay (picograms per milliliter +/- standard error of the mean). Onset of partial bypass was followed by a significant rise in systemic arterial thromboxane B2 levels: after cannulation, 115 +/- 21 pg/ml; after the onset of partial bypass, 596 +/- 141 pg/ml; p less than 0.01). Significant transcardiac thromboxane B2 gradients were found during the first and second cardioplegic washouts (CP-1: aortic root 73 +/- 12 pg/ml, coronary sinus 306 +/- 86 pg/ml, p less than 0.01; CP-2: aortic root 65 +/- 11 pg/ml, coronary sinus 355 +/- 98 pg/ml, p less than 0.01). Transcardiac gradients of 6-keto-prostaglandin F1 alpha and thromboxane B2 were obtained at CP-1 and CP-2. Gradients of 6-keto-prostaglandin F1 alpha were not different from thromboxane B2 gradients during CP-1 but were significantly higher than thromboxane B2 gradients during CP-2. In a subgroup of five dogs, transcardiac thromboxane B2, lactate, and platelet gradients were measured simultaneously. Cardiac thromboxane B2 generation was found only in the presence of cardiac lactate production. Transcardiac platelet gradients were significantly higher at CP-1 (13,900 +/- 3,000/mm3) than at CP-2 (4,000 +/- 1,230/mm3) (p less than 0.05), whereas thromboxane B2 gradients were similar at CP-1 and CP-2. Our study demonstrates that thromboxane B2 is released into the coronary circulation during surgical cardioplegic arrest with anaerobiosis.

Subcutaneous technique for saphenous vein harvest.

A subcutaneous technique of saphenous vein harvesting is described, and the results of its use in 37 consecutive patients requiring two or more grafts are presented. The technique minimizes the handling of the vein and reduces leg wound complications and patient discomfort.

Hard-shell cardiotomy reservoir for reinfusion of shed mediastinal blood.

We conducted a prospective, randomized, controlled trial comparing homologous blood consumption between groups of patients receiving conventional mediastinal drainage (group 1) or reinfusion of shed mediastinal blood (group 2) using hard-shell cardiotomy reservoir. One hundred consecutive patients who had elective coronary artery or valvular operations were studied. The two groups were comparable with regard to age, sex, weight, preoperative and postoperative hemoglobin levels, and surgical procedure. Group 2 patients had their shed mediastinal blood reinfused for up to 18 hours postoperatively; otherwise, the two groups were treated identically. For groups 1 and 2, average mediastinal blood losses were 705 +/- 522 and 822 +/- 445 mL and homologous blood consumption was 3.83 +/- 2.58 and 3.15 +/- 2.05 U, respectively (neither measure was significantly different). However, if blood losses exceeded 500 mL, there was a statistically significant reduction in homologous blood requirements in group 2 as compared with matched controls in group 1. This difference was most significant in patients with the greatest mediastinal losses.

Early rupture of a saphenous vein graft.

Early rupture of a saphenous vein graft used for coronary artery surgery has not been previously reported. In a 69-year-old man having a third coronary by-pass procedure, one of the saphenous vein grafts ruptured on the 8th postoperative day. The other vein graft showed marked aneurysm formation at two sites. Histological examination of the ruptured graft revealed that this was due to a bacterial infection within the wall of the vein. Although he survived an emergency operation to control the haemorrhage and replace the ruptured graft, he died some days later of mediastinitis. It appeared that both the rupture of the graft and the ensuing mediastinitis were due to a primary infective process within the saphenous vein used for the graft.

Left ventricular free wall rupture after coronary artery surgery.

A patient who had undergone urgent coronary artery bypass grafting for unstable angina developed a fatal left ventricular free wall rupture in the early postoperative period. Heart rupture following surgical revascularisation has not been reported before.

Systolic and diastolic interaction in the assessment of left ventricular function following surgical cardioplegia.

Using regionally implanted sonomicrometry crystals, we have evaluated a new index of regional function (normalised systolic shortening [NSS]) which integrates the systolic and diastolic properties of the left ventricle. Eight dogs (group I) were subjected to standard cardiopulmonary bypass and 45 min of hypothermic (10 degrees C), hyperkalaemic (25 mEq) crystalloid cardioplegia. Seven dogs (group II) underwent occlusion of the left anterior descending (LAD) coronary artery 5 min prior to initiation of cardiac arrest. The occlusion was released after 20 min, before the second cardioplegia infusion. Sarnoff left ventricular (LV) function curves were performed pre-arrest and 20, 40 and 60 min after removal of the cross-clamp. Regional assessment of myocardial function showed 55% +/- 3%, 70% +/- 3% and 70% +/- 5% recovery in the LAD region and 52% +/- 2%, 83% +/- 3% and 88% +/- 4% recovery in the circumflex (Cx) region of group I. In group II the LAD region recovered 27% +/- 1%, 31% +/- 3% and 38% +/- 3% and the Cx region showed 61% +/- 3%, 55% +/- 1% and 65% +/- 5% recovery. Comparison of the new index of ventricular function to standard indices of regional and global function demonstrate that the latter underestimate the degree of myocardial dysfunction after cardioplegic arrest, particularly in situations of acute regional myocardial ischaemia and uneven myocardial protection. The utilization of this index should provide a better standard for the more accurate assessment of interventions designed to decrease myocardial injury during cardioplegic arrest.

Normothermic arrest with continuous hyperkalaemic blood: initial experience.

The requirement for hypothermia in myocardial protection has recently been questioned. Between October 1990 and May 1991, diastolic arrest was achieved using continuous perfusion with normothermic, hyperkalaemic blood in 257 consecutive patients undergoing cardiac surgery. The mean age was 59.8 +/- 9.3 years (range 28-84 years). Coronary artery surgery was performed in 210 patients, valve replacements in 18, combined procedures in 22, and 7 patients had miscellaneous procedures. Eleven patients (4.3%) had undergone previous cardiac surgery, and 65 (25.3%) required urgent or emergency operations. Hyperkalaemic blood (7-20 mmol/l) was delivered antegradely in 190 (72.8%) patients (mean aortic root pressure 60-80 mmHg), retrogradely in 62 (25.3%) patients (mean coronary sinus pressure less than 40 mmHg), and by a combined route in 5 (1.9%). Sinus rhythm returned immediately after removal of the aortic clamp in 235 (91.4%) patients. Weaning from bypass was achieved without circulatory support in 207 (82.5%) patients. Of 233 patients undergoing non-emergency coronary artery surgery, single valve or combined procedures, 11 died, giving an operative mortality of 4.7%. Of 155 patients with good left ventricular function requiring coronary artery surgery, 3 (1.9%) died. The in-hospital mortality for the group as a whole was 7.3%. Sixteen (6.2%) patients sustained perioperative myocardial infarctions; of these 6 died. We conclude that continuous, normothermic, hyperkalaemic arrest is a simple and safe method of myocardial protection. It may avoid the damage associated with hypothermia, ischaemia and reperfusion.

Continuous warm versus intermittent cold blood cardioplegia for coronary bypass surgery in patients with left ventricular dysfunction.

Between October 1991 and March 1994, 108 consecutive patients with moderate to severe left ventricular dysfunction underwent non-emergency isolated coronary artery surgery under the care of one surgeon (A.R.). They were prospectively randomised to receiving either intermittent cold (Group 1-50 patients) or continuous warm (Group 2-58 patients) blood cardioplegia for myocardial protection. There were no significant differences in clinical outcome between the two groups, as judged by operative mortality, rates of perioperative myocardial infarction, the serum CKMB isoenzyme level at 2 and 18 h after operation, need for circulatory support, postoperative neurological deficit, or duration of hospital stay. Group 2 patients required significantly more potassium (68 vs 29 mmol, P < 0.001) to maintain diastolic arrest and also had higher serum potassium levels after removal of the cross-clamp (P < 0.001). However, sinus rhythm returned spontaneously with greater frequency (91.2% vs 45.8%, P < 0.001) in Group 2 patients. In conclusion this report suggests that retrograde continuous warm blood cardioplegia provides comparable myocardial protection to that achieved with retrograde intermittent cold blood cardioplegia in patients with moderate to severe left ventricular dysfunction undergoing isolated coronary artery surgery.

A prospective randomised study of continuous warm versus intermittent cold blood cardioplegia for coronary artery surgery: preliminary report.

Between October 1991 and March 1993, 281 consecutive patients underwent non-emergency isolated coronary artery surgery under the care of one surgeon (A.R.). They were prospectively randomised to receive either intermittent cold (Group I-144 patients) or continuous warm (Group II-137 patients) blood cardioplegia for myocardial protection. There were no significant differences in clinical outcome between the two groups, as judged by operative mortality, rates of peri-operative myocardial infarction, blood loss, need for circulatory support, post-operative neurological deficit, or duration of intensive care or hospital stay. However, sinus rhythm returned spontaneously with greater frequency (91.2% vs 45.8%, P < 0.001) in Group II patients. There was greater transmyocardial oxidative stress in Group I patients, as evidenced by a significant rise in oxidised glutathione in coronary sinus blood on myocardial reperfusion. Also, the serum CKMb isoenzyme level 2 h post-operatively was significantly raised in Group I patients, although this difference had disappeared by the day after surgery. In conclusion this preliminary report suggests that continuous warm blood cardioplegia provides comparable myocardial protection to that achieved with standard hypothermic techniques in patients undergoing coronary artery surgery.

Repair of post-infarct ventricular septal defect with or without coronary artery bypass grafting in the northwest of England: a 5-year multi-institutional experience.

OBJECTIVE: To present the 5-year experience of the northwest of England's surgical repair of post myocardial infarction (MI) ventricular septal defects (VSD). Our primary aim was to evaluate the effect of concomitant coronary artery bypass grafting (CABG) on mid-term survival and also to identify prognostic indicators. METHODS: A multi-centre regional observational study involving clinical data from 65 consecutive patients who underwent post MI VSD repair in the northwest of England between April 1997 and March 2002. Both prospective and retrospective collection of preoperative, operative and postoperative information was performed. Patient follow-up was performed by linking their records to the National Strategic Tracing Service database. Multivariate logistic regression and Cox proportional hazards analyses were used to identify independent risk factors for poor prognosis. RESULTS: Of the 65 patients included in the study, 42 (64.6%) underwent concomitant CABG with a median of two grafts. The majority of patients who had their coronary arteries grafted had multivessel disease (92.9%). Overall 30-day mortality was 23.1%. Predictors of poor prognosis included preoperative inotropes (P<0.001) and total occlusion of infarct related artery (P=0.03). The crude hazard ratio (HR) of mid-term mortality for concomitant CABG patients was 0.82 [95% confidence interval (CI) 0.38-1.78; P=0.62]. After adjustment for differences in patient and disease characteristics, the adjusted HR of mid-term mortality for concomitant CABG patients was 0.17 (95% CI 0.04-0.74; P=0.019). The adjusted freedom from death in the concomitant CABG patients at 30 days, 1, 2, and 4 years was 96.2%, 91.6%, 88.8%, and 82.8%, respectively, compared with 79.1%, 58.8%, 49.1%, and 32.2% for the non-concomitant CABG patients. CONCLUSION: These data provide evidence that concomitant CABG is significantly beneficial to mid-term mortality rates. We recommend that patients who present with post MI VSD who have multivessel disease should be routinely revascularised.

The effect off-pump coronary artery bypass surgery on in-hospital mortality and morbidity.

OBJECTIVE: Off-pump coronary artery bypass (OPCAB) surgery is being increasingly reported to show better outcomes compared to conventional on bypass grafting. We examined the effect of OPCAB on in-hospital mortality and morbidity, while adjusting for patient and disease characteristics, in four institutions in the North West of England. METHODS: Between April 1997 and March 2001, 10,941 consecutive patients underwent isolated coronary artery bypass surgery at these four institutions. Of these, 7.7% were performed off-pump. We used logistic regression to examine the effect of OPCAB on in-hospital mortality and morbidity after adjusting for potentially confounding variables. RESULTS: The crude odds ratio (OR) for death (off-pump versus on-pump coronary bypass grafting) was 0.48 (95% confidence interval, CI 0.26-0.92; P=0.023). After adjustment for all major risk factors, the OR for death was 0.59 (95% CI 0.31-1.12; P=0.105). Off-pump patients had a substantially reduced risk of post-operative stroke (0.6 versus 2.3%, respectively; adjusted OR 0.26 (95% CI 0.09-0.70; P=0.008) and a significant reduction in post-operative hospital stay. Other morbidity outcomes were similar in both groups. CONCLUSIONS: Off-pump coronary artery bypass incurs no increased risk of in-hospital mortality. In contrast, there is a significant reduction in morbidity in patients undergoing off-pump coronary bypass grafting when compared to that performed on cardiopulmonary bypass.

Predicting blood pressure reactivity and heart rate variability from mood state following coronary artery bypass surgery.

STUDY OBJECTIVES: Coronary Artery Bypass Graft (CABG) surgery is a common and successful procedure for revascularisation. However, the experience can induce emotional reactions prior to and following surgery. This study aimed to document changes in blood pressure (BP) reactivity and heart rate variability (HRV) following CABG surgery, and to determine the impact of mood state, particularly anxiety and depression upon cardiovascular functioning. METHOD: Twenty-two patients preparing to receive elective, first time CABG surgery were recruited from The Cardiothoracic Centre, Liverpool, UK and psychologically assessed using the Hospital Anxiety and Depression Scale (HAD), Global Mood Scale (GMS) and the Dispositional Resilience Scale (DRI). BP and heart rate responses were also measured during four conditions: baseline response; laboratory session; ambulatory monitoring; and self-initialised recordings during the ambulatory period. In addition, HRV was measured for 12 h in conjunction with the ambulatory monitoring period. All measures were assessed 1 week prior to surgery and 2 months following surgery. RESULTS: A significant decrease in negative mood and an increase in positive mood were reported following surgery. Forty percent of patients were clinically anxious and depressed prior to surgery although this was reduced to 27% after surgery. Depression was the strongest independent predictor of pre-operative BP and HRV whilst anxiety was most significantly related to follow-up BP reactivity. DBP was most strongly predicted by mood state. CONCLUSIONS: These results suggest that patients with higher levels of anxiety and depression are at risk of reduced HRV and increased BP reactivity in response to mental stressors. The study also strongly suggests that current patient services should be expanded to acknowledge the role of psychological factors within clinical prognosis after CABG surgery.

A survey of current myocardial protection practices during coronary artery bypass grafting.

OBJECTIVE: To identify current myocardial protection strategies for coronary artery bypass grafting (CABG) across the UK and Ireland. METHODS: A questionnaire survey of 15 questions was sent to practising cardiac surgeons between June and October 2002. The list of surgeons was obtained from the Society of Cardiothoracic Surgeons of Great Britain and Ireland database and they were contacted by postal and electronic mail. RESULTS: 118 (73.7%) out of 160 surgeons responded to the survey. 61 (51.7%) perform CABG on-pump (ONCAB) while 10 (8.5%) practice off-pump CABG (OPCAB). 47 (39.8%) perform either depending on individual cases. Of the 108 surgeons performing ONCAB, 91 (84.3%) use cardioplegia while 17 (15.7%) use cross-clamp and fibrillation techniques. Of those using cardioplegia, 76 (83.5%) use blood cardioplegia, 15 (19.7%) use warm-blood and 60 (78.9%) use cold-blood cardioplegia. 15(16.5%) use crystalloid cardioplegia. Retrograde cardioplegia is used by 23 (25.2%). We find an interesting variation of practice in relation to specifics like warm induction, graft cardioplegia, hot-shot, single cross-clamp, hypothermia and venting procedures. An overwhelming majority of surgeons performing OPCAB use the Octopus stabiliser (n=44, 77.2%) with some others preferring the Genzyme system. Supplementary stabilisation is not commonly used. While most OPCAB surgeons use intracoronary shunts (n=51), some prefer blockers (n=9) and others use coronary sloops (n=36). Ischaemic preconditioning is not commonly practised. Several surgeons have changed their practice of myocardial protection in the last 5 years (n=45). CONCLUSIONS: This survey gives us an interesting insight into current myocardial protection practices in the UK and Ireland and may be useful for future reference.

Cervical thymectomy in the treatment of myasthenia gravis.

A retrospective review of 22 patients undergoing cervical thymectomy for myasthenia gravis is presented. Their ages ranged from 19 to 67 years. The male and female ratio as well as the severity of illness prior to operation were similar to other reported series. All patients were evaluated from the standpoint of clinical response to thymectomy, and the number and dosage of anti-myasthenic drugs required after operation. There was a statistically significant improvement in clinical status in the immediate postoperative period (P less than 0.05) and a further significant improvement was noted at six months (P less than 0.05). In addition, significant reductions in postoperative drug therapy were noted (P less than 0.05). Complications from cervical thymectomy were minimal and mortality was zero. An attempt was made to correlate histological findings with clinical results. Comparison is made to other series in the literature and the advantages of the cervical technique as the initial surgical approach are described. The data presented support a useful role for cervical thymectomy in the treatment of myasthenia gravis.

Transmitral Doppler assessment of left ventricular diastolic function during coronary artery bypass surgery.

OBJECTIVE: To evaluate which Doppler transmitral velocity indices of left ventricular diastolic function change with alteration of left ventricular filling pressure. METHODS: Twenty-two patients undergoing coronary artery bypass surgery. The effect of fluid loading on indices derived from the transmitral Doppler waveform, recorded by a trans-oesophageal echocardiography, was evaluated using a generalised linear statistical model. RESULTS: E-wave maximum velocity, E-wave acceleration time and slope, E-wave deceleration slope, A-wave maximum velocity and E/A wave maximum velocity ratio showed significant changes after alterations in left ventricular filling pressure. E-wave deceleration time and E-wave maximum velocity/time velocity integral showed no significant change after fluid loading. CONCLUSION: Several commonly used Doppler derived indices of left ventricular diastolic function are significantly affected by changes in filling pressure of the left ventricle. This may limit the usefulness of the Doppler method for serial assessment of diastolic function when the left ventricular filling pressure has changed between assessments. Only the E-wave deceleration time did not show significant changes and might be a useful Doppler index for the serial measurement of left ventricular compliance but this needs to be confirmed with haemodynamic measurements.