Internal Mammary Arteries as a Model to Demonstrate Restoration of the Impaired Vasodilation in Hypertension, Using Liposomal Delivery of the CYP1B1 Inhibitor, 2,3',4,5'-Tetramethoxystilbene.

A significant number of patients with severe cardiovascular disease, undergoing coronary artery bypass grafting (CABG), present with hypertension. While internal mammary arteries (IMAs) may be a better alternative to vein grafts, their impaired vasodilator function affects their patency. Our objectives were to (1) determine if inhibition of the cytochrome P450 enzyme CYP1B1, using liposome-encapsulated 2,3',4,5'-tetramethoxystilbene (TMS), can potentiate vasodilation of IMAs from CABG patients, and (2) assess mechanisms involved using coronary arteries from normal rats, in an ex vivo model of hypertension. PEGylated liposomes were synthesized and loaded with TMS (mean diameter 141 ± 0.9 nm). Liposomal delivery of TMS improved its bioavailability Compared to TMS solution (0.129 ± 0.02 ng/mL vs. 0.086 ± 0.01 ng/mL at 4 h; p < 0.05). TMS-loaded liposomes alleviated attenuated endothelial-dependent acetylcholine (ACh)-induced dilation in diseased IMAs (@ACh 10−4 M: 56.9 ± 5.1%; n = 8 vs. 12.7 ± 7.8%; n = 6; p < 0.01) for TMS-loaded liposomes vs. blank liposomes, respectively. The alleviation in dilation may be due to the potent inhibition of CYP1B1 by TMS, and subsequent reduction in reactive oxygen species (ROS) moieties and stimulation of nitric oxide synthesis. In isolated rat coronary arteries exposed to a hypertensive environment, TMS-loaded liposomes potentiated nitric oxide and endothelium-derived hyperpolarization pathways via AMPK. Our findings are promising for the future development of TMS-loaded liposomes as a promising therapeutic strategy to enhance TMS bioavailability and potentiate vasodilator function in hypertension, with relevance for early and long-term treatment of CABG patients, via the sustained and localized TMS release within IMAs.

Determinants of outcomes following surgery for type A acute aortic dissection: the UK National Adult Cardiac Surgical Audit.

AIMS: Operability of type A acute aortic dissections (TAAAD) is currently based on non-standardized decision-making process, and it lacks a disease-specific risk evaluation model that can predict mortality. We investigated patient, intraoperative data, surgeon, and centre-related variables for patients who underwent TAAAD in the UK. METHODS AND RESULTS: We identified 4203 patients undergoing TAAAD surgery in the UK (2009-18), who were enrolled into the UK National Adult Cardiac Surgical Audit dataset. The primary outcome was operative mortality. A multivariable logistic regression analysis was performed with fast backward elimination of variables and the bootstrap-based optimism-correction was adopted to assess model performance. Variation related to hospital or surgeon effects were quantified by a generalized mixed linear model and risk-adjusted funnel plots by displaying the individual standardized mortality ratio against expected deaths. Final variables retained in the model were: age [odds ratio (OR) 1.02, 95% confidence interval (CI) 1.02-1.03; P < 0.001]; malperfusion (OR 1.79, 95% CI 1.51-2.12; P < 0.001); left ventricular ejection fraction (moderate: OR 1.40, 95% CI 1.14-1.71; P = 0.001; poor: OR 2.83, 95% CI 1.90-4.21; P < 0.001); previous cardiac surgery (OR 2.29, 95% CI 1.71-3.07; P < 0.001); preoperative mechanical ventilation (OR 2.76, 95% CI 2.00-3.80; P < 0.001); preoperative resuscitation (OR 3.36, 95% CI 1.14-9.87; P = 0.028); and concomitant coronary artery bypass grafting (OR 2.29, 95% CI 1.86-2.83; P < 0.001). We found a significant inverse relationship between surgeons but not centre annual volume with outcomes. CONCLUSIONS: Patient characteristics, intraoperative factors, cardiac centre, and high-volume surgeons are strong determinants of outcomes following TAAAD surgery. These findings may help refining clinical decision-making, supporting patient counselling and be used by policy makers for quality assurance and service provision improvement.

Exceptional response to chemotherapy followed by concurrent radiotherapy and immunotherapy in a male with primary retroperitoneal serous Adenocarcinoma: a case report and literature review.

BACKGROUND: Primary retroperitoneal serous adenocarcinoma (PRSA) is an extremely uncommon malignancy exclusively reported in females. Due to the rarity of the disease, it is difficult to establish a standardized treatment. CASE PRESENTATION: We describe a unique case of PRSA in a 71-year-old male who presented with right-sided lower back pain and numbness. Magnetic resonance imaging identified a mass invading the adjacent psoas muscle and twelfth rib. Tissue biopsy confirmed poorly differentiated PRSA. Patient was initially treated with neoadjuvant carboplatin and paclitaxel chemotherapy regimen. This resulted in complete radiological resolution of the tumor. However, 12 weeks later, rapid recurrence was noted on follow-up CT scan. The patient was then treated with external radiotherapy with concurrent nivolumab, an anti-PD-1 antibody. The patient displayed a positive response to treatment with reduction in primary tumor and metastases and had a sustained disease control. CONCLUSION: Treatment with radiotherapy in combination with anti-PD-1 antibody could be an effective modality of management for PRSA.

Reflection From UK Aortic Group: Frozen Elephant Trunk Technique as Optimal Solution in Type A Acute Aortic Dissection.

Diseases of the thoracic aorta are increasing in prevalence worldwide. Recent data indicated wide regional variation in the volume and complexity of aortic cases undertaken in United Kingdom cardiac centers, especially in case of acute type A aortic dissection (ATAAD) conditions. Patients treated in high-volume centers with a specific multidisciplinary aortic program had a significant reduction in ATAAD mortality when compared with low-volume centers. Following the initial phase of a national aortic center reorganization, the current study reflects the initial experience of a national collective of cardiothoracic surgeons with expertise in complex aortic surgery, using frozen elephant trunk as standard technique for the surgical treatment of patients affected by ATAAD. Between June 2013 and October 2017, 66 ATAAD patients (45% women) underwent hybrid aortic arch and frozen elephant trunk repair with the Thoraflex hybrid graft at 8 UK high-volume aortic centers. The in-hospital mortality accounted for 8 patients (12%). Postoperative temporary or permanent neurologic events and temporary renal replacement therapy occurred in 17% and 20% of patients, respectively. No spinal cord injury events were documented. Our data were similar to those reported in literature in the 2 largest experiences with the use of frozen elephant technique in ATAAD condition (in-hospital/30-day mortality: 11-12%). This initial experience demonstrated that frozen elephant technique can potentially be adopted as standard approach in life-threatening aortic diseases, with acceptable complication and mortality rates.

Is there a prospect for hybrid aortic arch surgery?

The surge of endovascular repair of aortic aneurysm in current modern aortic surgery practice has been the key for surgical management of elective cases of thoracic aortic aneurysms. This has paved way for the combined hybrid approach to be amongst the armamentarium for the management of aortic arch disease. The pivotal understanding of the aortic arch natural history coupled with device technology advancement allowed surgeons insight into delivery of hybrid surgery with acceptable morbidity and mortality results. This review article provides current insights into hybrid technique of aortic arch aneurysm repair and the evidences behind its applicability to arch surgery. It is aimed to highlight the challenges encountered for this innovative approach and correlate its challenges to those that are met by the conventional open aortic arch repair.

Open aortic arch surgery: the gold standard method.

Aortic arch pathologies are complex and treating them requires close team collaboration and technical skills to provide safe outcomes with low morbidity and mortality rates. Such challenges are facing both aortic and vascular surgeons. Open aortic arch repair has been the standard method of practice in all cases of aortic arch pathologies for the last four decades since the very first successful published case series by Griepp et al. during 1975. However, since then, repair of multi-segmented thoracic aortic pathologies has been explored through endovascular techniques; this is with or without open repair as a one-stage procedure especially in high-risk and elderly patients. Although the role of endovascular techniques in thoracoabdominal aorta is well established, its utilization as solo technique in aortic arch pathologies remains debatable. In this review, we highlight current evidences behind using open, endovascular, and hybrid procedures in aortic arch surgery.

Valve-Sparing Aortic Root Repair Compared to Composite Aortic Root Replacement: A Systematic Review and Meta-Analysis.

BACKGROUND: Aortic root aneurysms represent a significant risk of morbidity and mortality. Composite root replacement is the preferred practice for repair, although recently valve-sparing replacement has become a popular alternative. The study aim was to identify comparative studies that simultaneously analyzed composite root and valve-sparing root replacement outcomes. METHODS: A systematic review of the current literature was performed through four major databases, from inception until 2016. All comparative studies of valve-sparing versus composite root replacement were identified. All studies were assessed by two reviewers for their applicability and inclusion. RESULTS: A total of 12 comparative papers was identified encompassing 2,352 patients (700 valve-sparing and 1,652 composite); the mean follow up was 3.7 ± 1.7 years. Aortic cross-clamp and cardiopulmonary bypass times were lower in the composite group (p <0.0001 and p<0.00001, respectively). In-hospital mortality was low, but higher in the composite group (p = 0.002). Only one study reported long-term follow up. In studies reporting reoperation, there was slight difference favoring composite over valve-sparing replacement (p = 0.05). CONCLUSIONS: Valve-sparing and composite root replacement remain feasible options for replacement of the aortic root. Long-term data of comparative studies are not yet available to assess the viability of these procedures.

In patients with extensive subcutaneous emphysema, which technique achieves maximal clinical resolution: infraclavicular incisions, subcutaneous drain insertion or suction on in situ chest drain?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: 'In patients with extensive subcutaneous emphysema, which technique achieves maximal clinical resolution: infraclavicular incisions, subcutaneous drain insertion or suction on in situ chest drain?'. Altogether more than 200 papers were found using the reported search, of which 14 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. Subcutaneous emphysema is usually a benign, self-limiting condition only requiring conservative management. Interventions are useful in the context of severe patient discomfort, respiratory distress or persistent air leak. In the absence of any comparative study, it is not possible to choose definitively between infraclavicular incisions, drain insertion and increasing suction on an in situ drain as the best method for managing severe subcutaneous emphysema. All the three techniques described have been shown to provide effective relief. Increasing suction on a chest tube already in situ provided rapid relief in patients developing SE following pulmonary resection. A retrospective study showed resolution in 66%, increasing to 98% in those who underwent video-assisted thoracic surgery with identification and closure of the leak. Insertion of a drain into the subcutaneous tissue also provided rapid sustained relief. Several studies aided drainage by using regular compressive massage. Infraclavicular incisions were also shown to provide rapid relief, but were noted to be more invasive and carried the potential for cosmetic defect. No major complications were illustrated.

Can the temporary use of right ventricular assist devices bridge patients with acute right ventricular failure after cardiac surgery to recovery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: Can the temporary use of right ventricular assist devices (RVADs) bridge patients to recovery who suffer acute right ventricular failure after cardiac surgery? More than 183 papers were found using the reported search, of which 13 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. Indications for surgical intervention included coronary artery bypass surgery, valve replacement, post-heart transplant and left ventricular assist device insertion. Significant reductions in central venous pressure (P = 0.005) and mean pulmonary artery pressures (P < 0.01) were reported during and after RVAD support. Furthermore, increases in right ventricular cardiac output (P < 0.05), right ventricular ejection fraction (P < 0.05), right ventricular stroke work (P < 0.05) and pulmonary artery oxygen saturations (P < 0.05) were also seen. Assessment by one study showed that on Day 7 after RVAD removal, the right ventricular ejection fraction had increased by up to 40%. Dynamic echocardiography studies performed before, during and after RVAD placement demonstrated that after RVAD implantation, right ventricular end-diastolic dimensions (P < 0.05) and right atrial dimensions decreased (P < 0.05) and right ventricular ejection fraction (P < 0.05) increased. Although several studies successfully weaned patients from an RVAD, there were several complications, including bleeding requiring surgical intervention. However, this may be reduced by using percutaneous implantation (bleeding incidence: 4 of 9 patients) rather than by a surgically implanted RVAD (bleeding incidence: 5 of 5 patients). However, mortality is higher in percutaneous RVAD patients rather than in surgical RVAD (80-44%) patients. Causes of death cited for patients on an RVAD included multiorgan failure, sepsis, thromboembolic events, reoccurring right heart failure and failure to wean due to persistent right ventricular failure. We conclude that RVADs have been successfully used to bridge patients to recovery after cardiac surgery; however, RVADs carry numerous risks and a high mortality rate.

Is stereotactic ablative radiotherapy equivalent to sublobar resection in high-risk surgical patients with stage I non-small-cell lung cancer?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'Is stereotactic ablative radiotherapy equivalent to sublobar resection in high-risk surgical patients with Stage I non-small cell lung cancer?'. Altogether over 318 papers were found, of which 18 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. Stereotactic ablative radiotherapy (SABR) and sublobar resection (SLR) offer clear survival benefit in the treatment of early-stage non-small-cell lung cancer (NSCLC) in high-risk patients unsuitable for lobectomy and SABR has shown good results in medically operable patients. No randomized data are available comparing SLR and SABR, and therefore, data from prospective studies were compared. Overall survival at 1 year was similar between patients treated with SABR and SLR (81-85.7 vs 92%); however, overall 3-year survival was higher following SLR (87.1 vs 45.1-57.1%). There was no statistically significant difference in local recurrence in patients treated with SABR compared with SLR (3.5-14.5 vs 4.8-20%). Both treatment modalities are associated with complications. Fatigue (31-32.6%), pneumonitis (2.1-12.5%) and chest wall pain (3.1-12%) were common following SABR; however, serious grade 3 and 4 toxicity were rare. Morbidity following SLR was reported between 7.3 and 33.7%. Thirty-day mortality following SABR was 0%, while predicted 30-day mortality following a lung resection, using the thoracoscore predictive model ranges between 1 and 2.6%. Treatment for early-stage NSCLC should be tailored to individual patients. SABR is an acceptable alternative to SLR in high-risk patients but comparative data are required.

Does the use of thiopental provide added cerebral protection during deep hypothermic circulatory arrest?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: Does the use of thiopental provide added cerebral protection during deep hypothermic circulatory arrest (DHCA)? Altogether, more than 62 papers were found using the reported search, of which 7 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. Four of the seven papers used thiopental alongside other neuroprotective methods and agents. The methods included the use of ice packs to the head and core systemic hypothermia. Agents used alongside thiopental included nicardipine and mannitol. Thiopental was found to have the ability to lower oxygen consumption, where oxygen consumption was measured using the phosphocreatinine and adenosine triphosphate ratio. The neuroprotective effect of thiopental was evaluated by assessing the electrical activity of the brain during circulatory arrest, by which it was shown to be advantageous. However, other trials suggested that adding thiopental during circulatory arrest did not provide any extra protection to the brain. The timing of thiopental administration is of importance in order to gain positive outcomes, as it's ability to lower the cerebral energy state may result in unfavourable results if added before hypothermic circulatory arrest, where this may lead to an ischaemic event. We conclude that the use of thiopental during deep hypothermic circulatory arrest is beneficial, but if administered too early, it may replete the cerebral energy state before arrest and prove to be detrimental.

Does retraction of the sternum during median sternotomy result in brachial plexus injuries?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'does retraction of the sternum during median sternotomy result in brachial plexus injuries or peripheral neuropathies?' Altogether 58 papers were found using the reported search, of which 12 represented the best evidence to answer the question. The authors, date, journal and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. Caudal placement of the retractor or relieving the pressure superiorly by removing the upper blades of a retractor (P = 0.02) and use of a caudally placed symmetrical retractor has been shown to reduce neuropathy. Positioning of the patient with 'hands up' positioning showed significant reduction in the incidence of brachial plexus injuries. Furthermore, how wide the retractor is opened and use of an asymmetrical retractor for internal mammary artery (IMA) harvesting are also important factors in quantifying risk of postoperative neuropathy. Wider sternal retraction and longer bypass time did increase the risk of developing postoperative neuropathy. Three asymmetrical retractors were looked at that demonstrates the Delacroix-Chevalier to be the safest (P < 0.05). We conclude that median sternotomy risks brachial plexus injury and where possible the sternum should be opened as small a distance as possible with symmetrical retractor and using a caudally placed retractor.

Is cerebrospinal fluid drainage of benefit to neuroprotection in patients undergoing surgery on the descending thoracic aorta or thoracoabdominal aorta?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'Is cerebrospinal fluid (CSF) drainage of benefit in patients undergoing surgery on the descending thoracic aorta or thoracoabdominal aorta?' Altogether 1177 papers were found using the reported search, of which 17 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. Ten of 13 studies demonstrate significant neurological protection from CSF drainage (± additional adjuncts), with two further papers showing no significant difference between patients who had or had not had CSF drainage and one study unable to provide any conclusions. For patients having surgery on the thoracic aorta or thoracoabdominal aorta CSF drainage, maintaining pressures <10 mmHg (P < 0.03), in conjunction with other neuroprotective strategies, minimizes the risk of neurological sequelae when compared with patients treated with similar adjuncts but without CSF drainage. The majority of studies used additional neuroprotective strategies, including cooling and reattachment of the intercostal arteries as adjuncts to CSF drainage. Logistic regression curves demonstrated that the longer the ischaemia time, the greater the benefit from CSF drainage (P < 0.04). Four papers observed complications of CSF drainage, of which the main complications were: catheter occlusion or dislodgement, headache, meningitis and subdural haematoma. Overall, CSF drainage does offer a neuroprotective benefit; preventing paraplegia if CSF pressures are maintained <10 mmHg.

Is it worth packing the head with ice in patients undergoing deep hypothermic circulatory arrest?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: Is it worth packing the head with ice in patients undergoing deep hypothermic circulatory arrest (DHCA)? Altogether more than 34 papers were found using the reported search, of which 7 represented the best evidence to answer the clinical question, 5 of which were animal studies, 1 was a theoretical laboratory study and 1 study looked at the ability to cool using circulating water 'jackets' in humans. There were no available human studies looking at the neurological outcome with or without topical head cooling with ice without further adjunct methods of cerebral protection. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Four papers studied animals undergoing DHCA for 45 min-2 h depending on the study design, with or without packing the head with ice. The studies all demonstrated improved cerebral cooling when the head was packed with ice during DHCA. They also illustrated an improved neurological outcome, with better behavioural scores (P < 0.05), and in some, survival, when compared with animals whose heads were not packed in ice. One study examined selective head cooling with the use of packing the head with ice during rewarming after DHCA. However, they demonstrated worse neurological outcomes in these animals, possibly due to the loss of cerebral vasoregulation and cerebral oedema. One study involved a laboratory experiment showing improved cooling using circulating cool water in cryotherapy braces than by using packed ice. They extrapolated that newer devices to cool the head may improve cerebral cooling during DHCA. The final study discussed here demonstrated the use of circulating water to the head in humans undergoing pulmonary endarterectomy. They found that tympanic membrane temperatures could be maintained significantly lower than bladder or rectal temperatures when using circulating water to cool the head. We conclude that topical head cooling with ice is of use during DHCA but not during rewarming following DHCA and that it may be possible to advance topical head cooling techniques using circulating water rather than packed ice.

Is radiofrequency ablation more effective than stereotactic ablative radiotherapy in patients with early stage medically inoperable non-small cell lung cancer?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'is radiofrequency ablation more effective than stereotactic ablative radiotherapy in patients with early stage medically inoperable non-small cell lung cancer?' Altogether, over 219 papers were found, of which 16 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. Radiofrequency ablation (RFA) and stereotactic ablative radiotherapy (SABR) offer a clear survival benefit compared with conventional radiotherapy in the treatment of early stage non-small cell lung cancer (NSCLC) in medically inoperable patients. Overall survival at 1 year (68.2-95% vs. 81-85.7%) and 3 years (36-87.5% vs. 42.7-56%) was similar between patients treated with RFA and SABR. However, 5-year survival was higher in SABR (47%) than RFA (20.1-27%). Local progression rates were lower in patients treated with SABR (3.5-14.5% vs. 23.7-43%). Both treatments were associated with complications. Pneumothorax (19.1-63%) was the most common complication following RFA. Fatigue (31-32.6%), pneumonitis (2.1-12.5%) and chest wall pain (3.1-12%) were common following SABR. Although tumours ≤ 5 cm in size can be effectively treated with RFA, results are better for tumours ≤ 3 cm. One study documented increased recurrence rates with larger tumours and advanced disease stage following RFA. Another study found increasing age, tumour size, previous systemic chemotherapy, previous external beam radiotherapy and emphysema increased the risk of toxicity following SABR and suggested that risk factors should be used to stratify patients. RFA can be performed in one session, whereas SABR is more effective if larger doses of radiation are given over two to three fractions. RFA is not recommended for centrally based tumours. Patients with small apical tumours, posteriorly positioned tumours, peripheral tumours and tumours close to the scapula where it may be difficult to position an active electrode are more optimally treated with SABR. Treatment for early stage inoperable NSCLC should be tailored to individual patients, and under certain circumstances, a combined approach may be beneficial.

In patients undergoing video-assisted thoracoscopic surgery excision, what is the best way to locate a subcentimetre solitary pulmonary nodule in order to achieve successful excision?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In patients undergoing video-assisted thoracoscopic surgery (VATS) excision, what is the best way to locate a subcentimetre solitary pulmonary nodule (PN) in order to achieve successful excision?' Altogether, 107 papers were found using the reported search, of which 19 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 were tabulated. The hook-wire technique showed a varied success rate ranging from 58 to 97.6% and a relatively higher failure rate due to wire dislodgement. The most common complication of this method was pneumothorax. CT-guided spiral-wire localization displayed a success rate of 86% with the added advantage of providing more stability than the hook-wire technique and permitting manipulation. Radio-guided localization techniques and fluoroscopic-aided methods using contrast media displayed consistently high sensitivities with few complications. The radio-guided technique had the benefit of allowing a longer time-period between the staining of the nodule and the operation. Ultrasonography showed sensitivities ranging from 92.6 to 100%; however, it is highly operator-dependent. Finger palpation was shown to achieve suboptimal results and should be avoided. We concluded that radio-guided surgery is a preferable method. It showed high accuracy with minimal complications and operator dependence in detecting subcentimetre PNs when compared with other techniques such as ultrasonography, finger palpation, fluoroscopic, hook-wire, spiral-wire and microcoil localization.

Is a fully heparin-bonded cardiopulmonary bypass circuit superior to a standard cardiopulmonary bypass circuit?

A best-evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'Is a fully heparin bonded cardiopulmonary bypass circuit superior to a standard cardiopulmonary bypass circuit?' Altogether more than 792 papers were found using the reported search, of which 13 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 (Table 1). The studies analysed show that perfusion with heparin-coated and heparin-polymer-coated bypass does not increase the risk of adverse effects but reduces blood loss, re-operation rates, ventilation time, length of intensive care unit (ICU) and hospital stay and is also associated with improved biocompatibility, as evidenced by platelet preservation, reduced leucocyte and complement activation, and proinflammatory cytokine production. The various coated circuits have comparable biocompatibility as evaluated by a range of inflammatory markers and clinical outcomes. Three studies documented a significant decrease in post-operative blood loss (P = 0.001-0.54) and a meta-analysis found that perfusion with a heparin-bonded circuit resulted in a reduction in blood transfusion requirements (20%), ventilation time (P < 0.01), length of time in the ICU (P < 0.01) and also hospital stay (P = 0.02). Two studies found reduced levels of polymorphonuclear elastase (P < 0.018-0.001) and two trials concluded that the use of heparin-coated circuits in combination with low-dose systemic heparin (activated clotting time >250) resulted in the greatest clinical benefit and improvement in inflammation. One study documented significant platelet preservation with the use of third-generation heparin-polymer-bonded circuits (P ≤ 0.05). We conclude that despite heparin-bonded and newer third-generation heparin-polymer-bonded cardiopulmonary bypass circuits having a greater cost per person, their improved clinical outcomes and biocompatibility in patients undergoing cardiac surgery make them a preferable option to standard non-heparin-bonded circuits.

Does getting smokers to stop smoking before lung resections reduce their risk?

A best-evidence topic in thoracic surgery was written according to a structured protocol. The question of whether the incidence of major pulmonary morbidity after lung resection was associated with the timing of smoking cessation was addressed. Overall 49 papers were found using the reported search outlined below, of which 7 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. In most studies, smoking abstinence was shown to reduce the incidence of post-operative pulmonary complications (PPCs) such as pneumonia, respiratory distress, atelectasis, air leakage, bronchopleural fistula and re-intubation. The timing of cessation is not clearly identified, although there is some evidence showing reduction in risk of PPCs with increasing interval since cessation. Two studies suggested that smoking abstinence for at least 4 weeks prior to surgery was necessary in order to reduce the incidence of major pulmonary events. Furthermore, it was also shown that a pre-operative smoke-free period of >10 weeks produced complication rates similar to those of patients who had never smoked. We conclude that smoking cessation reduces the risk of PPCs. All patients should be advised and counseled to stop smoking before any form of lung resection.