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.

Reliability of different body temperature measurement sites during aortic surgery.

OBJECTIVE: We retrospectively performed a comparative analysis of temperature measurement sites during surgical repair of the thoracic aorta. METHODS: Between January 2004 and May 2006, 22 patients (mean age: 63 ± 12 years) underwent operations on the thoracic aorta with arterial cannulation of the aortic arch concavity and selective antegrade cerebral perfusion (ACP) during deep hypothermic circulatory arrest (HCA). Indications for surgical intervention were acute type A dissection in 14 (64%) patients, degenerative aneurysm in 6 (27%), aortic infiltration of thymic carcinoma in 1 (4.5%) and intra-aortic stent refixation in 1 (4.5%). Rectal, tympanic and bladder temperatures were evaluated to identify the best reference to arterial blood temperature during HCA and ACP. RESULTS: There were no operative deaths and the 30-day mortality rate was 13% (three patients). Permanent neurological deficits were not observed and transient changes occurred in two patients (9%). During re-warming, there was strong correlation between tympanic and arterial blood temperatures (r = 0.9541, p<0.001), in contrast to the rectal and bladder temperature (r = 0.7654, p = n.s; r = 0.7939, p = n.s., respectively). CONCLUSION: We conclude that tympanic temperature measurements correlate with arterial blood temperature monitoring during aortic surgery with HCA and ACP and, therefore, should replace bladder and rectal measurements.

Long-term statin administration to dams on high-fat diet protects not only them but also their offspring from cardiovascular risk.

We aimed to study the effects of long-term statin administration to high fat (HF)-fed female mice from the time they were weaned through to pregnancy and lactation on cardiovascular and metabolic risk factors in their HF-fed offspring. Female C57 mice on HF (45% kcal fat) were given pravastatin in their drinking water from the time they were weaned, during pregnancy and lactation. Weaned offspring were then fed an HF diet until adulthood generating the dam/offspring dietary groups HF/HF and HF plus pravastatin from the time dams were weaned, during pregnancy and lactation/HF (HF+S/HF). These groups were compared with offspring from mothers fed standard chow (control) which were then fed a control diet up to adulthood (control/control; C/C). HF+S dams showed significantly reduced total cholesterol concentrations and systolic blood pressure (SBP) versus HF dams. The reduction in total cholesterol and SBP in the HF+S dams did not restore values to those observed in the C group. Both male and female HF+S/HF offspring were significantly lighter in weight, and had lower SBP and serum cholesterol concentrations versus HF/HF. HF/HF offspring had elevated C-reactive protein levels but HF+S/HF animals of both sexes had reduced levels similar to those found in the C/C group. Long-term pravastatin administration to dams not only protects them from the deleterious effects of an HF diet, but this long-term maternal statin protection also has an equal and permanent effect in both male and female offspring up to their adult life, which is a novel finding.

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.

Left ventricular true and false aneurysms identified by cardiovascular magnetic resonance.

Left ventricular aneurysms are uncommon complications of myocardial infarction. However, it is important to identify them because they are associated with increased morbidity and mortality. True aneurysms tend to be managed conservatively whereas false aneurysms, because of the risk of rupture, are usually treated with urgent surgery. Distinguishing these two subtypes is therefore critical and cardiovascular magnetic resonance (MR) is being used more frequently to characterise the type of aneurysm as well as to provide clear three-dimensional images of aneurysm morphology. We present a very rare case of a true and a false aneurysm of the left ventricle in the same patient. MR enabled accurate delineation of both aneurysms and the late gadolinium-enhancement images provided evidence confirming both true and false aneurysms to be present.

Unidentified retained inferior vena cava myxoma detected by intra-operative trans-oesophageal echocardiography.

We report a unilateral right atrial familial myxoma with a multicentric nature discovered during cardiac surgery. After the patient was weaned off cardiopulmonary bypass, an inferior vena cava myxoma was discovered with intra-operative trans-oesophageal echocardiogram (TOE) which had been missed preoperatively and during surgery.

Effect of a low-protein diet during pregnancy on expression of genes involved in cardiac hypertrophy in fetal and adult mouse offspring.

Gene markers for cardiomyocyte growth, proliferation and remodeling were examined in mouse fetuses and adult male offspring exposed to maternal low-protein (LP) diet during pregnancy. Whole heart volume, measured by magnetic resonance imaging, was smaller in day 15 LP fetuses v. those from chow-fed dams (C), whereas heart volume was greater in adult LP v. C offspring. These LP offspring were hypertensive and had larger cardiomyocytes v. C animals. The mRNA levels of cyclin G1, a marker for cell growth, were lower in LP fetal hearts v. C hearts, but similar in the left ventricle of adult LP and C offspring. Opposite trends were found in brain natriuretic peptide levels (a marker of cardiac hypertrophy). Thus, maternal LP during pregnancy results in smaller fetal hearts and is accompanied by changes in expression of genes involved in cardiomyocyte growth, which are associated with cardiac hypertrophy and hypertension in adulthood.

A prospective randomized study to evaluate the renoprotective action of beating heart coronary surgery in low risk patients.

OBJECTIVES: Cardiopulmonary bypass (CPB) is widely regarded as an important contributor to renal failure, a well recognized complication following coronary artery surgery (coronary artery bypass grafting (CABG)). Anecdotally off-pump coronary surgery (OPCAB) is considered renoprotective. We examine the extent of renal glomerular and tubular injury in low-risk patients undergoing either OPCAB or on-pump coronary artery bypass (ONCAB). METHODS: Forty low-risk patients with normal preoperative cardiac and renal functions awaiting elective CABG were prospectively randomized into those undergoing OPCAB (n=20) and ONCAB (n=20). Glomerular and tubular injury were measured respectively by urinary excretion of microalbumin and retinol binding protein (RBP) indexed to creatinine (Cr). Daily measurements were taken from admission to postoperative day 5. Fluid balance, serum Cr and blood urea were also monitored. RESULTS: No mortality or renal complication were observed. Both groups had similar demographic makeup, Parsonnet score, functional status and extent of coronary revascularization (2.1+/-1.0 vs. 2.5+/-0.7 grafts; P=0.08). Serum Cr and blood urea remained normal in both groups throughout the study. A significant and similar rise in urinary RBP:Cr occurred in both groups peaking on day 1 (3183+/-2534 vs. 4035+/-4079; P=0.43) before reapproximating baseline levels. These trends were also observed with urinary microalbumin:Cr (5.05+/-2.66 vs. 6.77+/-5.76; P=0.22). Group B patients had a significantly more negative fluid balance on postoperative day 2 (-183+/-1118 vs. 637+/-847 ml; P=0.03). CONCLUSIONS: Although renal complication or serum markers of kidney dysfunction were absent, sensitive indicators revealed significant and similar injury to renal tubules and glomeruli following either OPCAB or ONCAB. These results suggest that avoidance of CPB does not offer additional renoprotection to patients at low risk of perioperative renal insult during CABG.

Off-pump coronary artery surgery.

Cardiopulmonary bypass has several associated deleterious effects that include a systemic inflammatory response, coagulopathy, central nervous system complications and a variable degree of end-organ damage. The recent upsurge in interest in "beating-heart" surgery attempts to avoid these deleterious effects. Advances in surgical technique, such as the use of intracoronary shunts and the Octopus retractor, have made beating-heart surgery a reality. The challenges for the anaesthetist are greater than for coronary artery surgery using cardiopulmonary bypass, and whilst some advantages are proven, such as the lack of the inflammatory response and the decreased need for blood or blood products, others have yet to be proved and there is a need for further research. The advantages and disadvantages need to be evaluated in randomised studies in order to confirm the safety and efficacy of these new techniques in terms of long-term graft patency and decreased morbidity.

A genetically engineered human Kunitz protease inhibitor with increased kallikrein inhibition in an ovine model of cardiopulmonary bypass.

A recombinant human serine protease inhibitor known as Kunitz protease inhibitor (KPI) wild type has functional similarities to the bovine Kunitz inhibitor, aprotinin, and had shown a potential to reduce bleeding in an ovine model of cardiopulmonary bypass (CPB). The aim of this study was to assess KPI-185, a modification of KPI-wild type that differs from KPI-wild type in two amino acid residues and which enhances anti-kallikrein activity in a further double-blind, randomized study in an ovine model of CPB, and to compare with our previous study of KPI-wild type and aprotinin in the same ovine model. Post-operative drain losses and subjective assessment of wound 'dryness' showed no significant differences between KPI-185 and KPI-wild type, despite the significant enhancement of kallikrein inhibition using KPI-185 seen in serial kallikrein inhibition assays. These preliminary findings support the hypothesis that kallikrein inhibition is not the major mechanism by which Kunitz inhibitors such as aprotinin reduce perioperative bleeding.

Transventricular cannulation of the aorta: a useful technique in acute aortic dissection.

A 39-year-old morbidly obese man suffered type-A acute aortic dissection. At operation, both external iliac and common femoral arteries were thrombosed. Transventricular cannulation of the ascending aorta provided the only means of maintaining adequate flow on cardiopulmonary bypass (CPB) to support an unusually high body mass index. This method of arterial cannulation for CPB was initially described in paediatric patients. We review the application of this technique in the adult population.

Autotransfusion decreases blood usage following cardiac surgery -- a prospective randomized trial.

INTRODUCTION: 10% of blood issued by the National Blood Service (220,000) is utilised in cardiac procedures. Transfusion reactions, infection risk and cost should stimulate us to decrease this transfusion rate. We tested the efficacy of autotransfusion of washed postoperative mediastinal fluid in a prospective randomized trial. PATIENTS AND METHODS: 166 patients undergoing coronary artery bypass grafting (CABG), valve or CABG + valve procedures were randomized into three groups. The indication for transfusion was a postoperative haemoglobin (Hb) < 10 g/l or a packed cell volume (PCV) < 30. When applicable, group A patients received washed post-operative drainage fluid. Group B all received blood processed from the cardiopulmonary bypass (CPB) circuit following separation from CPB and if appropriate washed post-operative drainage fluid. Group C were controls. Groups were compared using analysis of variance. RESULTS: There was no significant difference in age, sex, type of operation, CPB time and preoperative Hb and PCV between the groups. Blood requirements were as shown. [table - see text] Twelve patients in group A and 10 in group B did not require a homologous transfusion following processing of the mediastinal drainage fluid. CONCLUSION: Autotransfusion of washed postoperative mediastinal fluid can decrease the amount of homologous blood transfused following cardiac surgery. There was no demonstrable benefit in processing blood from the CPB circuit as well as mediastinal drainage fluid.

Endoscopic vein harvesting with the aid of carbon dioxide insufflation.

Endoscopic harvesting of the long saphenous vein has been introduced to decrease the morbidity of obtaining venous conduit for coronary artery bypass grafting. Herein is described an endoscopic method using carbon dioxide insufflation into the tissues around the vein. This has several advantages; improved vision, no physical retraction required, easier development of tissue planes, and improved hemostasis.

Novel approach to bleeding in patients undergoing cardiac surgery with liver dysfunction.

We describe two patients with significant liver dysfunction (Child--Pugh class B) who underwent cardiac surgery at our institution facilitated by the use of a prothrombin complex concentrate for the management of postoperative bleeding.

Retropericardial hematoma: pitfall in beating heart coronary surgery.

Beating heart coronary surgery, now an accepted technique of myocardial revascularization, is perceived to have fewer complications than the conventional on-pump approach. However, little attention has been paid to complications that may be specific to the off-pump method. We describe the unusual development of a large retropericardial hematoma following otherwise uneventful beating heart coronary surgery that resulted in global cardiac displacement. This was recognized and investigated promptly, and led ultimately to complete resolution without morbidity with expectant treatment alone. The implication of this observation is discussed along with other reports of perioperative complications following beating heart coronary surgery.

Novel application of vacuum assisted closure technique to the treatment of sternotomy wound infection.

Infection of the sternotomy wound is a potentially devastating and sometimes lethal complication following cardiac surgery. Established treatment may involve a combination of debridement, packing, delayed closure, plastic reconstruction, re-wiring and irrigation dependent on the severity of infection. Vacuum assisted closure, originally adopted for the treatment of non-healing wounds, has recently gained popularity among various surgical specialities in managing complex wound infection. Here we describe this novel technique of managing postoperative sternal wound infection.

Autotransfusion of washed shed mediastinal fluid decreases the requirement for autologous blood transfusion following cardiac surgery: a prospective randomized trial.

OBJECTIVES: The National Blood Service issues 2.2 million units of blood per year, 10% of these (220000) are utilized in cardiac procedures. Transfusion reactions, infection risk and cost should stimulate us to decrease this transfusion rate. We test the efficacy of autotransfusion following surgery in a prospective randomized trial. METHODS: One hundred and twelve patients undergoing CABG, valve or CABG + valve procedures were randomized into two groups. Group A received washed postoperative drainage fluid and group C were controls. The indication for transfusion was a postoperative haemoglobin (Hb) < 10 g/l or a PCV < 30. There was no significant difference in preoperative and operative variables between the groups. RESULTS: Twenty-eight patients in group A and 46 in group C required homologous transfusion (P = 0.0008). Group A patients required 298+/-49 ml of banked blood per patient, group C 508+/-49 ml (P = 0.003). There was no difference in total blood required (volume autotransfused + volume banked blood transfused) between the groups (group A 404+/-50 ml, group C 508+/-50 ml) or in mean total mediastinal fluid drainage (group A 652+/-51 ml, group C 686+/-50ml). The mean Hb concentration was significantly higher in group A on day 1 (11.2 g/dl+/-51 vs. 10.6 g/dl+/-13 (P = 0.002)). No morbidity was associated with autotransfusion. CONCLUSION: Autotransfusion can decrease the amount of homologous blood transfused following cardiac surgery. This represents a benefit to the patient and a decrease in cost to the health service.