Transapical perfusion for peri-arrest salvage during transcutaneous aortic valve implantation.

An 80-year-old man developed severe haemodynamic instability during a transapical aortic valve implantation. He was not suitable for a conventional surgical approach due to comorbidities and patent aortocoronary bypass grafts also limited further stabilizing actions. As a bail-out procedure, we demonstrate the feasibility of transapical arterial cannulation by crossing a newly implanted TAVI valve in order to establish an emergency bypass circuit.

Management options for aorto-oesophageal fistula: case histories and review of the literature.

OBJECTIVE: An aorto-oesophageal fistula is a rare clinical entity, leading to life-threatening gastrointestinal bleeding. Thoracic aortic aneurysms are the most common cause of aorto-oesophageal fistulae; further causes involve foreign body ingestion, trauma (in most cases iatrogenic), carcinoma or, very rarely, aortitis tuberculotica. METHODS: Due to its rarity, there are no large multicentre studies present to evaluate the efficacy of different therapeutic management options. Since it is associated with significant morbidity and mortality, we give a short summary of various treatment approaches performed in our clinical practice in the past three years. The most straightforward therapeutic option may be an endovascular aortic repair and subtotal oesophageal resection followed by gastro-oesophageal reconstruction, but other alternative treatment possibilities are also present, although with probable higher morbidity. CONCLUSIONS: Eliminating the source of bleeding as an emergency, resecting the oesophagus urgently to prevent sepsis and reconstructing the gastrointestinal continuity as an elective case after having the inflammatory processes settled seems to justify the endovascular aortic repair and subtotal oesophageal resection, followed by a gastro-oesophageal reconstruction, as an effective surgical approach.

Emergency intensive care admission following elective thoracic surgery.

AIM: The aim of this study was to analyse the outcomes of patients admitted to the intensive care unit (ICU) following initial recovery after elective thoracic surgery. METHODS: The case notes of all patients who underwent elective thoracic surgery over a one-year period were reviewed. Patients who were admitted to ICU following an initial recovery on the ward were identified and their postoperative course analysed. The clinical and demographic characteristics of these patients were recorded and their outcomes analysed. RESULTS: A total of 20 patients were admitted to ICU of whom 13 (65%) were admitted for respiratory complication, 5 with sepsis and 2 with cardiovascular instability. Sixteen (80%) patients required CPAP or BIPAP, of whom only 7 (35%) required mechanical ventilation. Renal support was required in 7 patients, with 2 (10%) requiring haemofiltration. ICU survival was 15 patients (75%), whilst overall three-month survival post ICU admission was 65%. Requirement for renal support was the only predictor of mortality on univariate and multivariate analysis. CONCLUSIONS: Salvage ICU admission following elective thoracic surgery is associated with significant mortality, however the outcome is far from hopeless. The majority of patients can be managed without recourse to mechanical ventilation or haemofiltration. The need for renal support is, however, a significant adverse prognostic indicator.

Retrograde cerebral perfusion: clinical experience in emergency and elective aortic operations.

We recently have used retrograde cerebral perfusion via the superior vena cava in association with hypothermic circulatory arrest as an adjunct to cerebral protection during aortic arch operations. Between April 1993 and March 1994, 23 patients (14 male; 9 female; median age, 64 years; age range, 25 to 76 years; 14 emergency, 9 elective) underwent operation on the ascending aorta, aortic arch, or both for acute dissection (11) or aneurysm (12). Aortic root replacement was performed in 13 patients (7 with arch replacement), ascending aortic replacement in 7 (4 with arch replacement), isolated aortic arch replacement in 2, and repair of sinus of Valsalva aneurysm in 1. Coronary artery bypass grafting was performed in 4 patients. Hypothermic circulatory arrest (15 degrees C) and retrograde cerebral perfusion were implemented in all cases (median circulatory arrest time, 21 minutes; range, 13 to 51 minutes; median retrograde cerebral perfusion time, 20 minutes; range, 12 to 50 minutes). Three hospital deaths occurred (atheromatous embolic stroke, sepsis, rupture of infrarenal aortic aneurysm). The remaining patients had no neurologic damage (median intensive therapy unit stay, 1 day; range, 1 to 5 days). Retrograde cerebral perfusion is easy to establish and safe, and may improve brain protection during hypothermic circulatory arrest.

Acute pulmonary thromboembolism complicating pneumonectomy: successful operative management.

Pulmonary thromboembolism after pneumonectomy carries high fatality. Here we present a case of acute embolism to the left pulmonary artery with thrombus in the right atrium and inferior vena cava following right pneumonectomy. Diagnosis was made clinically and radiologically before proceeding to emergency surgery. Thromboembolectomy was successfully performed on cardiopulmonary bypass and the patient was subsequently discharged home after uneventful recovery.

Anomalous aortic origin of the right coronary artery. An unusual cause of angina pectoris and its surgical correction.

A 45-year-old female presented with typical recent-onset exertional angina pectoris. Subsequent investigation showed that the likely cause was an aberrant origin of the right coronary artery arising from the left coronary sinus. This anomaly is uncommon and is not usually associated with angina pectoris. Surgical rerouting of the origin of the right coronary artery produced complete resolution of ischaemia.

The threshold for air leak: stapled versus sutured human bronchi, and experimental study.

BACKGROUND: Little is known about the integrity of staple-closure of the bronchus and its tolerance to normal mechanical stresses (cough, sneezing, etc.) in the immediate early post-operative period. There are few studies which tested the mechanical strength of stapled bronchial closure compared with manually closed bronchi using the threshold for fluid leak across the bronchial suture line which differs from air. MATERIAL AND METHODS: Intact cadaveric tracheobronchial tree (n = 40) were selected, age range from 55 to 70, of which 60% were males. They were divided into two groups: group A, 20 left bronchi were closed with RLV 30 Ethicon 4.8 mm bronchial stapler; group B, 20 were closed with 4 0 Prolene simple interrupted sutures. All specimens were intubated with endotracheal tube and submerged under water before testing the immediate air leak with the standard 40 mm Hg inflation pressure. Inflation pressure was increased until air leak was detected. The stapled closures were resected and subjected to radiological examination. RESULTS: No air leak was detected in any bronchus at 40 mmHg regardless of the closure technique. The median leakage pressure was significantly higher in the hand sutured bronchi compared to the stapled group (200 vs. 105 mmHg, respectively) and 50% (n = 10) leaked from multiple sites in the stapled group compared with leakage from one site only in group B, this difference was statistically significant P < 0.001. The radiological appearance of the staples maintained the B configuration, recommended by the manufacturer as a sign of sound application. CONCLUSION: Hand sutured bronchi tolerated higher inflation pressure compared with the stapled ones before leaking air. Air leak at high pressure occurs in the presence of intact staples.

von Willebrand factor and urinary albumin excretion are possible indicators of endothelial dysfunction in cardiopulmonary bypass.

OBJECTIVE: Experimental evidence suggests that cardiopulmonary bypass (CPB) associated inflammatory response leads to endothelial injury and increased permeability, but this has been difficult to show clinically. We have investigated the use of von Willebrand factor (vWF), and urinary albumin excretion, as measured by the urinary albumin creatinine ratio (ACR), to demonstrate this. METHODS: A total of 23 patients undergoing elective coronary artery bypass grafting were studied. Complement fragment C3a, leukotrienne B4 (LTB4), interleukin 6 (IL6), neutrophil elastase, vWF and ACR were measured on anaesthetic induction (baseline), 20 min after starting CPB, 5 min after cross-clamp removal, 5 min, 2, 6 and 24 h after termination of CPB. Anaesthetic, CPB and myocardial protection techniques were standardised. ANOVA was performed by using the distribution free Friedman test for each measured parameter. When significance differences were found (P < 0.05), post hoc analysis with Wilcoxon signed rank test was used for comparison of each time point with the base line level and differences were only accepted as significant following the Bonferroni correction (P < 0.008). Summary measures of peak versus peak and area under the cure were also analysed for ACR with vWF. RESULTS: Peak vs. baseline levels for C3a were 4.9 vs. 2.1 microg/ml (P < 0.0001), LTB4 was 800 vs. 20 pg/ml (P < 0.0001), neutrophil elastase was 250 vs. 115 ng/ml (P < 0.001), IL6 was 620 vs. 1.4 pg/ml (P < 0.0001), vWF was 2.2 vs. 1.3 IU/ml (P < 0.0001) and ACR was 17.6 vs. 2.0 mg/mmol (P < 0.0001). C3a, LTB4 and ACR peaked during the operation. Neutrophil elastase peaked at 2 h following CPB. IL6 and vWF peaked at 6 h following CPB. The correlation coefficient between vWF and ACR following peak versus peak analysis was 0.48 (P = 0.035), and area under the curve analysis was 0.6 (P < 0.01). CONCLUSION: These results demonstrate that endothelial permeability and injury, as measured by urinary albumin excretion and vWF, respectively, are related and the use of these easily detectable and sensitive biochemical markers warrants further investigation.

Pericardial mesothelioma following mantle field radiotherapy.

A 49-year-old female was referred with recurrent pericardial effusion following mantle field radiotherapy for Hodgkin s lymphoma. She underwent video-assisted thoracoscopy and resection of a pericardial window. Intraoperatively she suffered a cardiac arrest and subsequently died in the early postoperative period despite maximal therapy. Pathological examination revealed extensive myocardial fibrosis and multiple nodules of pericardial mesothelioma. The latter has hitherto not been recognised following mediastinal radiation. The cardiac complications of mantle field radiotherapy are discussed.

Pentoxifylline preloading reduces endothelial injury and permeability in cardiopulmonary bypass.

Pentoxifylline (PTX), a methyl xanthine derivative, reduces endothelial permeability. A double blind, prospective, randomized, placebo controlled, parallel study was undertaken to assess the effect of PTX on leukotriene B4, complement fragment C3a, interleukin 6 (IL6), endothelial injury as measured by von Willebrand factor (vWf), and endothelial permeability as measured by urinary albumin excretion (expressed as excreted urinary albumin to creatinine ratio [ACR]) in patients undergoing cardiopulmonary bypass (CPB) for elective coronary artery bypass grafting. Twenty patients were recruited into each treatment arm and given either PTX 400 mg or placebo three times daily for 1 week before surgery. Patients were well matched. All operations were performed using one anesthetic, CPB, and a myocardial protection technique. Blood and urine samples were taken after anesthetic induction (baseline); 20 min after the start of CPB; 5 min after removal of the cross clamp; and 5 min and 2, 6, and 24 hr after the end of CPB. Pentoxifylline did not reduce IL6, C3a, and LTB4 release but reduced Factor VIIIRAg and urinary albumin excretion preoperatively (PTX vs placebo, ACR 1q.0 vs 2.1 mg/mmol, vWf 0.8 vs 1.3 IU/ml, p < 0.05) and peak levels (PTX vs placebo, ACR 8.9 vs 16.2, vWf 1.2 vs 2.2, p < 0.05) after CPB. These results suggest that PTX may attenuate the endothelial injury and permeability seen in CPB.

Hemofiltration in a cardiac intensive care unit: time for a rational approach.

The typical annual expenditure for patients requiring continuous hemofiltration (CHF) is high. To audit the benefit of this expensive treatment, the outcome of 48 consecutive patients (34 men, 14 women; mean age, 65 years) requiring hemofiltration for acute renal failure was analyzed during a period of 24 months. The operations performed were 26 CABG, 8 AVR, 3 AVR/MVR, 2 post infarction VSD repairs, and 1 thoracoabdominal aneurysmectomy. Indications for hemofiltration were oliguria and fluid overload in 69%, uremia in 56%, acidosis in 33%, and hyperkemia in 13%. Twenty five patients (52%) died while in the hospital, and 10 more died within 9 months of discharge. Of the remaining 13 survivors, 6 (46%) were classified as III or IV according to the New York Heart Association classification system. The mean ITU and hospital stay per patient requiring CHF was 15.3 days and 25.4 days, respectively. There were no statistically significant differences between patients who did and did not survive in the hospital in age, pre-operative renal function, ejection fraction, duration of cardiopulmonary bypass, or urine output before CHF. However, there were no survivors when the cardiac index was less than 1.7 L/m2 and adrenalin requirement was more than 30 micrograms/min before CHF (seven patients). These results suggest that the short- and long-term outcome in patients requiring CHF after cardiac surgery is poor. Considering the large demand on resources, the use of CHF should be rationalized, particularly in patients with persistent low cardiac output.

The practice of cardiothoracic surgeons in the perioperative staging of non-small cell lung cancer.

BACKGROUND: The treatment and prognosis of non-small cell lung cancer, and assessment of the results of treatment, depend on accurate perioperative staging. The extent to which this is carried out in the United Kingdom is unknown. METHODS: A postal questionnaire survey was undertaken in 1990 to determine the perioperative staging practices of cardiothoracic surgeons in the United Kingdom. RESULTS: Replies from 77 surgeons, who between them performed about 4833 pulmonary resections a year for lung cancer, were analysed. Forty four per cent of surgeons, operating on 43% of the patients, do not perform computed tomography of the thorax or mediastinal exploration before surgery. They may therefore embark on a thoracotomy for stage III disease. At thoracotomy 45% of surgeons, operating on 40% of patients, do not sample macroscopically normal lymph nodes. They may therefore understage cases as N0/N1 when there is at least microscopic disease in mediastinal lymph nodes. CONCLUSIONS: The staging of lung cancer in the United Kingdom in 1990 appears in many instances to be inadequate. There should be a more organised approach to perioperative staging so that prognosis may be assessed and comparisons between groups of patients can be made.

Failed femorocrural reconstruction does not prejudice amputation level.

From January 1985 to December 1989, 500 consecutive patients presented to a single vascular unit with limb-threatening acute or critical ischaemia. Vascular reconstruction was attempted unless the patient had insufficient viable tissue to permit weight bearing or complete absence of run-off vessels in the calf. Fifty patients underwent a primary amputation and 450 patients underwent vascular reconstruction, of whom 265 had a femorocrural bypass. Sixty secondary amputations were performed following femorocrural bypass failure. The below-knee amputation to above-knee amputation ratio (BKA:AKA) was 2.0 in the primary amputation group and 1.1 in the secondary amputation group. Direct comparison between the two groups is not valid as they are clinically different. The combined BKA:AKA ratio was 1.4. This compares favourably with the BKA:AKA ratio of recent published series and figures from the National Amputation and Limb Fitting Services. It suggests that an unselective policy of vascular reconstruction for critical ischaemia does not lead to a higher proportion of above-knee amputations.

Iloprost reduces peripheral resistance during femoro-distal reconstruction.

A randomised placebo-controlled trial was conducted to investigate the effect of iloprost, a stable prostacyclin mimetic, on peripheral resistance during femoro-distal bypass. Patients undergoing femoro-distal long saphenous vein bypass for critical ischaemia received 3000 ng of iloprost or placebo infused into the graft via an unligated side branch over 2 min. Graft blood flow and peripheral resistance were measured for 20 min, using an operative Doppler flowmeter (OpDop 130, SciMed, U.K.) and a pressure transducer to record graft pressure. Postoperatively, graft blood flow was assessed by daily duplex ultrasound for 7 days. Iloprost produced an immediate drop in peripheral resistance in all cases (n = 18) by a mean (range) of 40% (4-80%) compared with controls (n = 15) in whom there was a 5.3% (-8 to +36%) increase in resistance (p less than 0.01, Wilcoxon test). Decreased peripheral resistance in iloprost-treated patients persisted to 20 min. The largest decreases in peripheral resistance occurred in patients with the highest initial resistances (r = 0.56, p less than 0.02). Graft flow during the same period increased by 52% (-7 to 294%) compared with controls in whom there was a 6% (-17 to 26%) increase in flow, (p less than 0.01). Flow remained elevated by 53% over baseline values at 1 week post-infusion in the iloprost-treated group but this did not achieve statistical significance compared to controls in whom flow also increased by 13%. Iloprost produces an immediate decrease in peripheral resistance associated with a prolonged increase in graft blood flow. This may reduce graft failure in the early postoperative period.

Reperfusion plasma contains a neutrophil activator.

Aortic aneurysm repair produces inflammatory mediators, neutrophil activation, and remote organ injury. Reperfusion plasma from these patients produces microvascular injury in an ex vivo chemotactic model. This study investigates the mechanism of this injury. Vena caval blood was obtained before and 15 minutes after aortic clamp removal (n = 16) or at laparotomy (n = 10). Plasma or saline solution was introduced into unit dose chambers fixed atop dermabrasions on the back of depilated anesthetized rabbits. Animals were treated with intravenous saline solution (n = 4); made neutropenic with nitrogen mustard (n = 4); pretreated with the xanthine oxidase inhibitor allopurinol (n = 4); or cotreated intravenously with the free radical scavengers superoxide dismutase (SOD) and catalase (n = 4). Three hours later neutrophil counts (polymorphonuclear cells [PMN]/mm3) and activity (free radical production by flow cytometry), protein leakage, and inflammatory mediators (thromboxane [TX] and leukotriene B4 [LTB4]) were measured. In contrast to control plasma in untreated rabbits, reperfusion plasma produced TX and LTB4 generation (1090 +/- 105 and 794 +/- 91 pg/ml, respectively, p < 0.01), PMN accumulation (1636 +/- 210/mm3, p < 0.01) and activation (276 +/- 31 mean fluorescent units), and microvascular permeability (554 +/- 90 micrograms/ml, p < 0.01). Neutropenia (3 +/- 1 PMN/mm3) and cotreatment with SOD and catalase abolished these responses, whereas pretreatment with allopurinol did not. Human reperfusion plasma contains a soluble factor that stimulates free radical generation by rabbit neutrophils to produce a microvascular injury characterized by de novo TX production, neutrophil accumulation and activation, and increased microvascular permeability to protein.

Adjuvant prostanoid treatment during femorodistal reconstruction.

A prospective randomized placebo-controlled trial was conducted to determine the effects of the stable prostacyclin analogue iloprost on early graft patency and hemodynamic parameters during femorodistal reconstruction for critical leg ischemia. Peripheral resistance and graft blood flow were measured using an operative Doppler flowmeter and graft pressure transducer. Postoperative graft surveillance was continued at 1-month and then at 3-month intervals by duplex Doppler ultrasonography, measurement of ankle-brachial pressure indices, and intravenous digital subtraction angiography when indicated. In patients receiving 3000 ng of iloprost (n = 45) infused into the graft on completion there was an immediate mean decrease in peripheral resistance of 44% that persisted to skin closure in comparison with controls (n = 38) in whom no such decrease in resistance occurred (p < 0.001, Wilcoxon test). During the same period, mean graft blood flow increased in iloprost-treated patients by 74.5% compared with controls in whom there was a 6% increase in flow (p < 0.001). Primary cumulative patencies at 1 month were significantly higher in iloprost-treated grafts, 98% compared to 83% for controls (p < 0.05, log-rank test). Cumulative primary patencies at 1 year and secondary patencies at 1 month and 1 year were also greater in the iloprost-treated group (67%, 98%, and 87.6%, respectively) compared to controls (65%, 86%, and 79.3%, respectively), but these did not achieve statistical significance. A single bolus infusion of iloprost has prolonged beneficial effects on graft blood flow and peripheral resistance during femorodistal reconstruction. This is reflected by improved early primary graft patencies.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic muscle stimulation improves ischaemic muscle performance in patients with peripheral vascular disease.

There is currently no established treatment for intermittent claudication with proven long term benefit. Exercise classes have been shown to improve walking distance. Chronic electromyostimulation (CEMS) a method of stimulating skeletal muscle has effects on normal muscle which may also benefit claudicants. We investigated the effects of one month of CEMS on claudicants in a single blind placebo controlled study. Patients were randomised to either CEMS (treatment) or transcutaneous nerve stimulation (TENS) placebo. The effects of the two modalities were assessed using the conventional measures of claudicating distance (CD), maximum walking distance (MWD), ankle-brachial pressure index (ABPI) and pressure recovery time (PRT). Muscle performance was assessed by the fatigue index (FI) a technique determining the decrease in ischaemic muscle response to repeated contraction. After 4 weeks treatment the CEMS group showed significant improvements in their median CD (88 to 111) and MWD (118 to 158); this was not seen in the control group. Muscle performance also increased significantly during the 4 weeks of treatment in the CEMS group but not in the control group. These changes were not maintained after CEMS was stopped. This pilot study suggests that CEMS may well have a role to play in the treatment of intermittent claudication though a number of further studies need to be undertaken.

Pharmacological reduction of the systemically damaging effects of local ischaemia.

Many patients with intermittent claudication are encouraged to exercise. However, transient exercise-induced muscle ischaemia results in systemic vascular endothelial injury associated with increased vascular permeability manifest as an increase in urinary albumin excretion. Repetitive systemic vascular endothelial injury leads to accelerated atherogenesis and may explain the high cardiovascular mortality rate of claudicants. Oxpentifylline, a haemorheological agent, has recently been shown to prevent vascular endothelial injury in animal models. A double-blind, placebo-controlled, cross-over trial was undertaken to determine the effect of oxpentifylline on exercise-induced systemic vascular endothelial injury in 20 claudicants. Urinary albumin, expressed as a creatinine ratio (ACR), was measured before and 1 and 2 hours after standardised exercise following 1 week treatment with either active drug or placebo. Oxpentifylline reduced the median (range) 1 hour post exercise increase in ACR from 0.35 (-0.46-12.72) to 0.02 (-6.00-14.10) mg/mmol. (p = 0.030, z = 2.2 Wilcoxon rank sign test). These results confirm that local ischaemia is associated with a potentially deleterious systemic effect and that it may be possible to attenuate this pharmacologically. The clinical significance of this is yet to be determined.