John Kneeshaw

Mitral repair best practice: proposed standards

Objectives: To define best practice standards for mitral valve repair surgery. Design: Development of standards for process and outcome by consensus. Setting: Multidisciplinary panel of surgeons, anaesthetists, and cardiologists with interests and expertise in caring for patients with severe mitral regurgitation. Main outcome measures: Standards for best practice were defined including the full spectrum of multidisciplinary aspects of care. Results: 19 criteria for best practice were defined including recommendations on surgical training, intraoperative transoesophageal echocardiography, surgery for atrial fibrillation, audit, and cardiology and imaging issues. Conclusions: Standards for best practice in mitral valve repair were defined by multidisciplinary consensus. This study gives centres undertaking mitral valve repair an opportunity to benchmark their care against agreed standards that are challenging but achievable. Working towards these standards should act as a stimulus towards improvements in care.

Successful Extracorporeal Membrane Oxygenation Support After Pulmonary Thromboendarterectomy

BACKGROUND Pulmonary thromboendarterectomy (PTE) is the treatment of choice for patients with chronic thromboembolic pulmonary hypertension. However, some patients develop severe cardiorespiratory compromise soon after separating from cardiopulmonary bypass, either from early reperfusion pulmonary edema or right ventricular failure secondary to residual pulmonary hypertension. Since 2005 we have used venoarterial extracorporeal membrane oxygenation (ECMO) support in this group that has no other therapeutic option. We review our experience of early ECMO support in the severely compromised patients post-PTE. METHODS We conducted a retrospective review of all patients undergoing PTE from a single national referral center between August 2005 and August 2007. RESULTS One hundred twenty-seven consecutive patients underwent PTE surgery. Seven patients (5.5%) had extreme cardiorespiratory compromise in the immediate postoperative period and required venoarterial ECMO support. Their mean age was 51.3 years with 3 males. When compared with patients not requiring ECMO, these patients had significantly poorer hemodynamic indices before the operation with mean pulmonary artery pressure of 62 mm Hg versus 51 mm Hg (p = 0.02) and pulmonary vascular resistance of 907 dynes/sec/cm(-5) versus 724 dynes/s(-1)/cm(-5) (p < 0.02). Mean duration of support was 119 hours (49 to 359 hours). Five patients were successfully weaned from ECMO support (73%) and 4 left the hospital alive, giving a salvage rate of 57%. For those who did not require ECMO support, hospital mortality was 4.2%. CONCLUSIONS Early venoarterial ECMO support has a role as rescue therapy post-PTE in patients with severe compromise who would probably otherwise die.

Circulatory arrest versus cerebral perfusion during pulmonary endarterectomy surgery (PEACOG): a randomised controlled trial

BACKGROUND For some surgical procedures to be done, a patients blood circulation needs to be stopped. In such situations, the maintenance of blood flow to the brain is perceived beneficial even in the presence of deep hypothermia. We aimed to assess the benefits of the maintenance of antegrade cerebral perfusion (ACP) compared with deep hypothermic circulatory arrest (DHCA). METHODS Patients aged 18-80 years undergoing pulmonary endarterectomy surgery in a UK centre (Papworth Hospital, Cambridge) were randomly assigned with a computer generated sequence to receive either DHCA for periods of up to 20 min at 20°C or ACP (1:1 ratio). The primary endpoint was change in cognitive function at 12 weeks after surgery, as assessed by the trail-making A and B tests, the Rey auditory verbal learning test, and the grooved pegboard test. Patients and assessors were masked to treatment allocation. Primary analysis was by intention to treat. The trial is registered with Current Controlled Trials, number ISRCTN84972261. FINDINGS We enrolled 74 of 196 screened patients (35 to receive DHCA and 39 to receive ACP). Nine patients crossed over from ACP to DHCA to allow complete endarterectomy. At 12 weeks, the mean difference between the two groups in Z scores (the change in cognitive function score from baseline divided by the baseline SD) for the three main cognitive tests was 0·14 (95% CI -0·14 to 0·42; p=0·33) for the trail-making A and B tests, -0·06 (-0·38 to 0·25; p=0·69) for the Rey auditory verbal learning test, and 0·01 (-0·26 to 0·29; p=0·92) for the grooved pegboard test. All patients showed improvement in cognitive function at 12 weeks. We recorded no significant difference in adverse events between the two groups. At 12 weeks, two patients had died (one in each group) [corrected]. INTERPRETATION Cognitive function is not impaired by either ACP or DHCA. We recommend circulatory arrest as the optimum modality for patients undergoing pulmonary endarterectomy surgery. FUNDING J P Moulton Charitable Foundation.

The impact of intra-operative transoesophageal echocardiography on cardiac surgical practice

The use of transoesophageal echocardiography during cardiac surgery has increased dramatically and it is now widely accepted as a routine monitoring and diagnostic tool. A prospective study was carried out between September 2004 and September 2007, and included all patients in whom intra‐operative echocardiography was performed, 2 473 (44%) out of a total of 5 591 cases. Changes to surgery were subdivided into predictable (where echocardiographic examination was planned specifically to guide surgery) and unpredictable (new pathology not diagnosed pre‐operatively). A change in the planned surgical procedure was documented in 312 (15%) cases. In 216 (69%) patients the changes were predictable and in 96 (31%) they were unpredictable. The number of predictable changes increased between 2004–5 and 2006–7 (8% vs 13%, p = 0.025). In these cases, intra‐operative echocardiography was specifically requested by the surgeon to help determine the operative intervention. This has implications for consent and operative risk, which have yet to be fully determined.

Vecuronium and atracurium infusions during hypothermic cardiopulmonary bypass

Two similar groups of patients undergoing coronary artery bypass grafting received either atracurium or vecuronium infusions for neuromuscular blockade. Both groups demonstrated a marked reduction in neuromuscular blocking requirements during hypothermic bypass at 30 C. The ratio of the dose rates at 30 C to that at 37 C was signijicantly less with vecuronium (p<0.01).

Recommendations for reporting perioperative transoesophageal echo studies

Every perioperative transoesophageal echo (TEE) study should generate a written report. A verbal report may be given at the time of the study. Important findings must be included in the written report. Where the perioperative TEE findings are new, or have led to a change in operative surgery, postoperative care or in prognosis, it is essential that this information should be reported in writing and available as soon as possible after surgery. The ultrasound technology and methodology used to assess valve pathology, ventricular performance and any other derived information should be included to support any conclusions. This is particularly important in the case of new or unexpected findings. Particular attention should be attached to the echo findings following the completion of surgery. Every written report should include a written conclusion, which should be comprehensible to physicians who are not experts in echocardiography.

Management of donors for heart and heart–lung transplantation

The quality of donor organs will determine the quality of life for the recipient and the importance of optimal management of the multi‐organ donor is that the organs may benefit up to five, critically ill, patients. The basic principle is to maintain sufficient preload to minimise the need for inotropic support and it is recommended that all multiple organ donors should have central venous and arterial pressure monitoring in addition to adequate venous access. The importance of the choice of fluid for volume expansion and the management of the hormonal disturbances which follow brain death are considered.

Mitral valve replacement in a patient with acute intermittent porphyria.

A cute intermittent porphyria (AIP) is a rare metabolic disorder which can be life-threatening when a porphyric crisis leads to generalized paralysis (1). Certain drugs are known to trigger such a crisis and other drugs have uncertain effects (2). Stress may also be a trigger factor (3). We describe a patient with AIP undergoing cardiac surgery involving hypothermic cardiopulmonary bypass. We present details of a seemingly safe anesthetic technique and porphobilinogen (PBG) measurements made in the perioperative period.

Intractable Ventricular Tachycardia Secondary to Cardiac Hemangioma

Cardiac tumors are rare and have a known association with ventricular dysrhythmias, especially ventricular tachycardia. We report a case of intractable ventricular tachycardia in a middle-aged man developing on a background of known, presumed benign, cardiac neoplasm. The ventricular tachycardia was controlled with long-term medical therapy. Surgical resection of the cardiac mass combined with cryoablation cured the dysrhythmia. Appearances at histopathology were those of a benign intracardiac hemangioma. Surgical treatment has an important but forgotten role in the management of ventricular arrhythmias, which is more definitive and carries a higher success rate compared with medical management.

Core Topics in Transesophageal Echocardiography

Core Topics in Transesophageal Echocardiography - Libros de Medicina - Ecocardiografia - 83,12