In patients with a tumour invading the phrenic nerve does prophylactic diaphragm plication improve postoperative lung function?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'In patients with tumours involving the phrenic nerve, does prophylactic diaphragm plication improve lung function following tumour resection?' Using the reported search, 258 papers were found of which 6 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Three case reports and one case series represent 37 patients in the literature along with two relevant animal studies. Patients treated with prophylactic plication at the time of injury or sacrifice of the phrenic nerve had reduced radiological evidence of diaphragm paralysis, lower reported shortness of breath and reduced requirement for ventilatory support. In patients with prophylactic diaphragm plication and a concurrent pulmonary resection, the predicted postoperative lung function correlated closely with the postoperative measured FEV1, FVC and gas transfer. The postoperative measured FEV1 was reported as 86-98%, the FVC 82-89% and gas transfer 97% of the predicted values. Two animal models investigate the mechanics of respiration, spirometry and gas exchange following diaphragmatic plication. A randomized control study in four dogs measured a 50% reduction in tidal volume and respiratory rate, a 40% decrease in arterial PO2 and a 43% increase in arterial CO2 when the phrenic nerve was crushed in animals with a pneumonectomy but without prophylactic diaphragm plication. A further randomized control animal study with 28 dogs found that plicating the diaphragm after unilateral phrenic nerve transection resulted in a significant increase in tidal volume and lung compliance and a significant decrease in respiratory frequency and the work of breathing. Prophylactic diaphragm plication may preserve lung function, reduce the risk of ventilator dependence and improve the mechanics of breathing in patients with phrenic nerve transection. If transection of the phrenic nerve occurs, and it is recognized intraoperatively, prophylactic diaphragm plication should be considered.

Off-pump coronary artery bypass grafting versus optimal medical therapy alone: effectiveness of incomplete revascularization in high risk patients.

BACKGROUND: Geriatric patients with multivessel coronary artery disease (CAD) are a challenging group to treat; these cases elicit discussion within heart teams regarding the actual benefit of undertaking major surgery on these patients and often lead to abandon the surgical option. Percutaneous procedures represent an important option, but coronary anatomy may be unfavorable. Off-pump coronary artery bypass (OPCAB) provides good quality graft on left anterior descending (LAD) without exposing the patient to cardiopulmonary bypass, and might be the ideal choice in patients with multiple comorbidities, not eligible to percutaneous or on-pump procedures. The objective of this study was to compare survival during a mid-term follow-up in high-risk patients with no percutaneous alternative, either treated with OPCAB or discharged in medical therapy. METHODS: We retrospectively evaluated from June 2008 to June 2013, 83 high-risk patients with multivessel CAD were included: 42 were treated with incomplete off-pump revascularization using left internal mammary artery (LIMA) on LAD; 41 were discharged in optimal medical therapy (OMT), having refused surgery. Follow-up ended in March 2015, with a telephonic interview. Primary endpoint was survival from all-cause mortality; secondary endpoints were survival from cardiac-related mortality and freedom from non-fatal major adverse cardiac events (MACEs). RESULTS: During follow up, 11 deaths in OPCAB group and 27 deaths in OMT group occurred. Death was due to cardiac factors in 6 and 15 patients, respectively. MACEs were observed in 6 patients in OPCAB group and in 4 patients in OMT group. With regards to survival from all-cause mortality, patients who underwent OPCAB survived more than those discharged in OMT (Log Rank < 0.001), and OMT group carries a propensity score-adjusted hazard ratio of 3.862 (P < 0.001). With regards to survival from cardiac-related events, patients who underwent OPCAB survived more than those discharged in OMT (Log Rank = 0.002), and OMT group carries a propensity score-adjusted hazard ratio of 3.663 (P = 0.010). There is no statistically significant difference concerning freedom from MACEs (Log Rank = 0.273). CONCLUSIONS: For high-risk patients with multivessel CAD, not eligible to on-pump complete revascularization surgery or percutaneous procedures, incomplete revascularization with OPCAB LIMA-on-LAD offers benefits in survival when compared to OMT alone.

Effect of Preoperative Aspirin Replacement With Enoxaparin in Patients Undergoing Primary Isolated On-Pump Coronary Artery Bypass Grafting.

Management of preoperative antiplatelet therapy in coronary artery bypass grafting (CABG) is variable among surgeons: guidelines collide with prejudices because replacement of aspirin with low-molecular-weight heparin is still performed because of a presumed minor bleeding risk. This study aims to analyze postoperative bleedings and complications in patients scheduled for elective primary isolated on-pump CABG, depending on preoperative aspirin treatment or its replacement with enoxaparin. In this cohort study, we propensity score matched 200 patients in whom aspirin was stopped at least 5 days before CABG and replaced with enoxaparin and 200 patients who continued aspirin therapy until the day before surgery. Postoperative bleedings and complications were monitored during hospitalization. Among patients who continued aspirin treatment, mean overall bleeding was 701.0 ± 334.6 ml, whereas in the matched enoxaparin group, it was significantly greater (882.6 ± 64.6 ml, p value <0.001); this was associated with reduced postoperative complications, lower values of postoperative C-reactive protein in aspirin takers, and a presumed protective effect for statins. After propensity score adjustment, aspirin treatment carried a protective effect against major postoperative bleeding (odds ratio 0.312, p = 0.001). In conclusion, postoperative bleeding is reduced in patients who continued aspirin, likely due to a reduction in postoperative inflammation. The practice of empirically discontinuing aspirin and replacing it with enoxaparin before CABG should be abandoned. Patients with coronary artery disease referred to CABG should continue antiplatelet medications until the surgical procedure. Those results might be extended to patients under oral anticoagulant therapy requiring CABG.

Non-surgical bleeding in cardiac surgery.

Bleeding is an occurrence stemming from complex interactions encountered in cardiac surgery and is often attributed to the perioperative administration of anti-thrombotic products if inadequate surgical haemostasis is excluded. Very occasionally, bleeding does not fit the norm and the aetiology is not a lack of surgical prolene or an iatrogenic-induced coagulopathy. Patients who present for cardiac surgery should be questioned carefully for a history of bleeding; however, patients at risk are not always identified. This case presents a series of haemorrhagic events incorrectly labelled as surgical complications resulting from an uncommon but not insignificant undiagnosed condition. The existing literature outlining protocols to safely manage patients with haemophilia during the perioperative cardiac surgical period is discussed in this report. This case explicitly demonstrates the importance of preoperative identification to avoid the morbidity that can result from cardiac surgery in an undiagnosed haemophilic patient.

Is there evidence that fresh frozen plasma is superior to antithrombin administration to treat heparin resistance in cardiac surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, 'in [patients with heparin resistance] is [treatment with FFP] superior [to antithrombin administration] in [achieving adequate anticoagulation to facilitate safe cardiopulmonary bypass]?' More than 29 papers were found using the reported search, of which six represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Antithrombin (AT) binds to heparin and increases the rate at which it binds to thrombin. The levels of antithrombin in the blood are an important aspect of the heparin dose-response curve. When the activated clotting time (ACT) fails to reach a target >480, this is commonly defined as heparin resistance (HR). Heparin resistance is usually treated with a combination of supplementary heparin, fresh frozen plasma (FFP) or antithrombin III concentrate. There is a paucity of evidence on the treatment of heparin resistance with FFP, with only five studies identified, including one retrospective study, one in vitro trial and three case reports. AT has been studied more extensively with multiple studies, including a crossover trial comparing AT to supplemental heparin and a multicentre, randomized, double blind, placebo-controlled trial. Antithrombin (AT) concentrate is a safe and efficient treatment for heparin resistance to elevate the activated clotting time (ACT). It avoids the risk of transfusion-related acute lung injury (TRALI), volume overload, intraoperative time delay and viral or vCJD transmission. Antithrombin concentrates are more expensive than fresh frozen plasma and may put patients at risk of heparin rebound in the early postoperative period. Patients treated with AT have a lower risk of further FFP transfusions during their stay in hospital. We conclude that the treatment of HR with FFP may not restore the ACT to therapeutic levels with adequate heparinization, but AT is efficient with benefits including lower volume administration, less risk of TRALI and lower risk of transfusion-related infections.