Effects of intraoperative diltiazem infusion on flow changes in arterial and venous grafts in coronary artery bypass graft surgery

Objective

This study aimed to show the effects of intra-operative diltiazem infusion on flow in arterial and venous grafts in coronary artery bypass graft surgery.

Methods

Hundred fourty patients with a total of 361 grafts [205 (57%) arterial and 156 (43%) venous] underwent isolated coronary surgery. All the grafts were measured by intraoperative transit time flow meter intra-operatively. Group A (n=70) consisted of patients who received diltiazem infusion (dose of 2.5 microgram/kg/min), and Group B (n=70) didn''t receive diltiazem infusion.

Results

Mean graft flow values of left internal mammary artery were 53 ml/min in Group A and 40 ml/min in Group B (P<0.001). Pulsatility index (PI) values of left internal mammary artery for Group A and Group B were 2.6 and 3.0 respectively (P<0.001). No statistically significant difference was found between venous graft parameters.

Conclusion

We recommend an effect of diltiazem infusion in increasing graft flows in coronary artery bypass graft operations.     

Surgical site infection in orthopedic trauma: A case–control study evaluating risk factors and cost

Background

With the shift of our healthcare system toward a value-based system of reimbursement, complications such as surgical site infections (SSI) may not be reimbursed. The purpose of our study was to investigate the costs and risk factors of SSI for orthopedic trauma patients.

Methods

Through retrospective analysis, 1819 patients with isolated fractures were identified. Of those, 78 patients who developed SSIs were compared to 78 uninfected control patients. Patients were matched by fracture location, type of fracture, duration of surgery, and as close as possible to age, year of surgery, and type of procedure. Costs for treatment during primary hospitalization and initial readmission were determined and potential risk factors were collected from patient charts. A Wilcoxon test was used to compare the overall costs of treatment for case and control patients. Costs were further broken down into professional fees and technical charges for analysis. Risk factors for SSIs were analyzed through a chi-squared analysis.

Results

Median cost for treatment for patients with SSIs was $108,782 compared to $57,418 for uninfected patients (p < 0.001). Professional fees and technical charges were found to be significantly higher for infected patients. No significant risk factors for SSIs were determined.

Conclusions

Our findings indicate the potential for financial losses in our new healthcare system due to uncompensated care. SSIs nearly double the cost of treatment for orthopedic trauma patients. There is no single driver of these costs. Reducing postoperative stay may be one method for reducing the cost of treating SSIs, whereas quality management programs may decrease risk of infection.     

Investigating bacterial growth in surgical theatres: establishing the effect of laminar airflow on bacterial growth on plastic, metal and wood surfaces

INTRODUCTION

Infection is a devastating complication of surgery. Intra-operative wound contamination is a common cause of infection. A number of measures have been effective in reducing wound contamination. One such measure is laminar flow. Controversy exists as to whether it is safe to keep open instruments and implants outside the laminar flow. This study compares bacterial contamination of wood, plastic and stainless steel within and outside the laminar flow.

MATERIALS AND METHODS

Identically shaped and sized tiles were left for 90 min within and outside the laminar flow and then cultured for bacterial growth.

RESULTS

A third of metal and plastic tiles were contaminated, but only 10% of wooden tiles, suggesting that wood is a more hostile environment for bacteria. There was no difference in contamination between tiles placed inside and those placed outside the laminar flow.

CONCLUSIONS

This study suggests that placing instruments and implants outside the laminar flow is a safe practice.     

Adherence to recommendations designed to decrease intra-operative wound contamination

INTRODUCTION

The incidence of wound infection following total hip and knee arthroplasty has fallen with the introduction of laminar vertical laminar airflow, occlusive clothing and prophylactic antibiotics. However, infection still occurs after prosthetic joint replacement and can have devastating consequences. Intra-operative wound contamination is the major source of infection. Measures proven to decrease intra-operative wound contamination include chlorhexidine lavage, removal of jewellery, covering old jewellery, ears, nose, mouth and hair and wearing theatre clothing in an occlusive manner.

PATIENTS AND METHODS

Posters explaining this practice were placed at eye level in the scrub area of orthopaedic theatres and adoption of these techniques was observed covertly before and after.

RESULTS

Eighty-two personnel were audited before the poster was erected and 90 afterwards. Only 2 of 12 observed standards were adhered to 100% of the time.

CONCLUSIONS

Education by posters did not significantly improve adherence to protocols. Compliance with protocols was worse amongst non-scrubbed theatre personnel.     

Prevention of Surgical Site Infection in Total Joint Arthroplasty: An International Tertiary Care Center Survey

Background

Prevention strategies are critical to reduce infection rates in total joint arthroplasty (TJA), but evidence-based consensus guidelines on prevention of surgical site infection (SSI) remain heterogeneous and do not necessarily represent this particular patient population.

Questions/Purposes

What infection prevention measures are recommended by consensus evidence-based guidelines for prevention of periprosthetic joint infection? How do these recommendations compare to expert consensus on infection prevention strategies from orthopedic surgeons from the largest international tertiary referral centers for TJA?

Patients and Methods

A review of consensus guidelines was undertaken as described by Merollini et al. Four clinical guidelines met inclusion criteria: Centers for Disease Control and Prevention''s, British Orthopedic Association, National Institute of Clinical Excellence''s, and National Health and Medical Research Council''s (NHMRC). Twenty-eight recommendations from these guidelines were used to create an evidence-based survey of infection prevention strategies that was administered to 28 orthopedic surgeons from members of the International Society of Orthopedic Centers. The results between existing consensus guidelines and expert opinion were then compared.

Results

Recommended strategies in the guidelines such as prophylactic antibiotics, preoperative skin preparation of patients and staff, and sterile surgical attire were considered critically or significantly important by the surveyed surgeons. Additional strategies such as ultraclean air/laminar flow, antibiotic cement, wound irrigation, and preoperative blood glucose control were also considered highly important by surveyed surgeons, but were not recommended or not uniformly addressed in existing guidelines on SSI prevention.

Conclusion

Current evidence-based guidelines are incomplete and evidence should be updated specifically to address patient needs undergoing TJA.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-013-9369-1) contains supplementary material, which is available to authorized users.     

High-concentration oxygen and surgical site infections in abdominal surgery: a meta-analysis

Background

There has been recent interest in using high-concentration oxygen to prevent surgical site infections (SSIs). Previous meta-analyses in this area have produced conflicting results. With the publication of 2 new randomized controlled trials (RCTs) that were not included in previous meta-analyses, an updated review is warranted. Our objective was to perform a meta-analysis on RCTs comparing high- and low-concentration oxygen in adults undergoing open abdominal surgery.

Methods

We completed independent literature reviews using electronic databases, bibliographies and other sources of grey literature to identify relevant studies. We assessed the overall quality of evidence using grade guidelines. Statistical analysis was performed on pooled data from included studies. A priori subgroup analyses were planned to explain statistical and clinical heterogeneity.

Results

Overall, 6 studies involving a total of 2585 patients met the inclusion criteria. There was no evidence of a reduction in SSIs with high-concentration oxygen (risk ratio 0.77, 95% confidence interval 0.50–1.19, p = 0.24). We observed substantial heterogeneity among studies.

Conclusion

There is moderate evidence that high-concentration oxygen does not reduce SSIs in adults undergoing open abdominal surgery.     

Graft pathology at the time of harvest: impact on long-term survival

Objective

This study aims to present the graft pathology at the time of harvest and its impact on long-term survival.

Methods

The remnants of the bypass grafts from 66 consecutive patients with coronary artery disease receiving a coronary artery bypass grafting were investigated pathologically, and pertinent predictive risk factors and survival were analyzed.

Results

Medial degenerative changes with or without intimal proliferation were present in 36.8%, 37.8% and 35.6% of left internal mammary artery (IMA), radial artery and saphenous vein grafts. There were 2 (3.0%) hospital deaths and 9 (14.1%) late deaths. Multinomial logistic regression revealed left IMA pathological changes, dyslipidemia, history of percutaneous transluminal coronary angioplasty/stent deployment and Y-graft were significant predictive risk factors negatively influencing the patients’ long-term survival. Kaplan-Meier survival analysis revealed that the long-term survival of patients with left IMA pathological changes were significantly reduced compared with those without (74.1% vs. 91.4%, P=0.002); whereas no differences were noted in long-term survivals between patients with and without pathological changes of the radial arterial or saphenous vein grafts.

Conclusion

Pathological changes may be seen in the bypass graft at the time of harvest. The subtle ultrastructural modifications and the expressions of vascular tone regulators might be responsible for late graft patency. The pathological changes of the left IMA at the time of harvest rather than those of the radial artery or saphenous vein graft affect significantly longterm survival. Non-traumatic maneuver of left IMA harvest, well-controlled dyslipidemia and avoidance of using composite grafts can be helpful in maintaining the architecture of the grafts.     

Reading the Small Print – Labelling Recommendations for Orthopaedic Implants

INTRODUCTION

There exist, currently, no clear guidelines regarding standards for surgical implant labelling. Dimensions of the laminar flow canopies in orthopaedic use fixes the distance at which implant labels can be read. Mistakes when reading the label on an implant box can pose health risks for patients, and financial consequences for medical institutions.

SUBJECTS AND METHODS

Using scientifically validated tools such as the Snellen Chart Formula, a theoretical minimum standard for text on implant labels was reached. This theoretical standard was then tested under real operating conditions. After discovering a minimum practical standard for implant labels, the authors then audited current labels in use on a wide range of orthopaedic implant packages. Furthermore, other non-text-related labelling problems were also noted.

RESULTS

There is a definite minimum standard which should be observed when implant labels are manufactured. Implants in current use bear labels on the packaging that are of an insufficient standard to ensure patient safety in theatre.

CONCLUSIONS

The authors have established text parameters that will increase the legibility of implant labels. In the interests of improving risk management in theatre, therefore, the authors propose a standard for orthopaedic implant labelling, and believe this will provide a useful foundation for further discussion between the orthopaedic community and implant manufacturers.     

Implantation of transcatheter aortic valve prosthesis through the ascending aorta concomitant with coronary artery bypass grafting without cardiopulmonary bypass

Introdution

The transcatheter aortic valve implantation in the treatment of high-risk symptomatic aortic stenosis has increased the number of implants every year. The learning curve for transcatheter aortic valve implantation has improved since the last 12 years, allowing access alternatives.

Objective

The aim of this study is to approach the implantation of transcatheter aortic valve through transaortic via associated with off-pump cardiopulmonary bypass surgery in a 67-year-old man, with chronic obstructive pulmonary disease, arterial hypertension and kidney transplant.

Methods

Off-pump coronary artery bypass surgery was performed and the valve in the aortic position was released successfully.

Results

There were no complications in the intraoperative and postoperative period. Gradient reduction, effective orifice increasing of the prosthesis and absence of valvular regurgitation after implantation were observed by transesophageal echocardiography.

Conclusion

Procedural success demonstrates that implantation of transcatheter aortic valve through the ascending aorta associated with coronary artery bypass surgery without CPB is a new option for these patients.     

Perioperative myocardial infarction in patients undergoing myocardial revascularization surgery

Introduction

Perioperative myocardial infarction adversely affects the prognosis of patients undergoing coronary artery bypass graft and its diagnosis was hampered by numerous difficulties, because the pathophysiology is different from the traditional instability atherosclerotic and the clinical difficulty to be characterized.

Objective

To identify the frequency of perioperative myocardial infarction and its outcome in patients undergoing coronary artery bypass graft.

Methods

Retrospective cohort study performed in a tertiary hospital specialized in cardiology, from May 01, 2011 to April 30, 2012, which included all records containing coronary artery bypass graft records. To confirm the diagnosis of perioperative myocardial infarction criteria, the Third Universal Definition of Myocardial Infarction was used.

Results

We analyzed 116 cases. Perioperative myocardial infarction was diagnosed in 28 patients (24.1%). Number of grafts and use and cardiopulmonary bypass time were associated with this diagnosis and the mean age was significantly higher in this group. The diagnostic criteria elevated troponin I, which was positive in 99.1% of cases regardless of diagnosis of perioperative myocardial infarction. No significant difference was found between length of hospital stay and intensive care unit in patients with and without this complication, however patients with perioperative myocardial infarction progressed with worse left ventricular function and more death cases.

Conclusion

The frequency of perioperative myocardial infarction found in this study was considered high and as a consequence the same observed average higher troponin I, more cases of worsening left ventricular function and death.     

Experimental laparoscopic aortobifemoral bypass for occlusive aortoiliac disease

Objective

To describe a totally laparoscopic technique for aortobifemoral bypass to treat aortoiliac atheromatous occlusive disease.

Design

A feasibility study.

Setting

A university teaching hospital.

Subjects

Six piglets weighing between 70 and 80 kg were submitted to a totally laparoscopic retroperitoneal aortobifemoral bypass, performed through six trocar sites, with abdominal suspension and a gasless technique. No minilaparotomy was performed. After systemic heparinization, the infrarenal aorta was cross-clamped and the aortic bifurcation stapled. An end-to-end aorto–prosthetic anastomosis was performed. Retroperitoneal tunnels were created to allow each limb of the graft to join its corresponding femoral artery by a conventional anastomosis.

Intervention

Totally laparoscopic aortobifemoral bypass.

Main Outcome Measures

Duration of the procedure, intraoperative blood loss and operative complications, bleeding in the immediate postoperative period. Evaluation of the aortic anastomosis at autopsy.

Results

All aortobifemoral bypasses were completed in less than 4 hours. Intraoperative blood loss did not exceed 250 mL. No intraoperative complication was encountered except occasional bleeding at the aortic anastomosis upon releasing the arterial clamp. This was controlled with a collagen sponge (three cases) or extra stitches (two cases). The animals were observed for 15 minutes before sacrifice. Autopsy revealed a normal aortic anastomosis in all cases and a normal progression of the limbs of the graft under the ureters in the retroperitoneal tunnels.

Conclusions

This animal model demonstrates the feasibility of the aortobifemoral bypass through a laparoscopic approach. The retroperitoneal anatomy of the piglet is similar to that of man. Aortic surgery can be conducted as for the standard technique. We used a similar approach to perform the first human, totally laparoscopic aortobifemoral bypass with an end-to-end anastomosis.     

The Seasonal Variability of Surgical Site Infections in Knee and Hip Arthroplasty

Background

Surgical site infections (SSIs) after total knee (TKA) and total hip (THA) arthroplasty are devastating to patients and costly to healthcare systems. The purpose of this study is to investigate the seasonality of TKA and THA SSIs at a national level.

Theatre Shoes — A Link in the Common Pathway of Postoperative Wound Infection?

INTRODUCTION

Operating department staff are usually required to wear dedicated theatre shoes whilst in the theatre area but there is little evidence to support the beneficial use of theatre shoes.

PATIENTS AND METHODS

We performed a study to assess the level of bacterial contamination of theatre shoes at the beginning and end of a working day, and compared the results with outdoor footwear.

RESULTS

We found the presence of pathogenic bacterial species responsible for postoperative wound infection on all shoe groups, with outdoor shoes being the most heavily contaminated. Samples taken from theatre shoes at the end of duty were less contaminated than those taken at the beginning of the day with the greatest reduction being in the number of coagulase-negative staphylococcal species grown. Studies have demonstrated that floor bacteria may contribute up to 15% of airborne bacterial colony forming units in operating rooms. The pathogenic bacteria we isolated have also been demonstrated as contaminants in water droplets spilt onto sterile gloves after surgical scrubbing.

CONCLUSIONS

Theatre shoes and floors present a potential source for postoperative infection. A combination of dedicated theatre shoe use and a good floor washing protocol controls the level of shoe contamination by coagulase-negative staphylococci in particular. This finding is significant given the importance of staphylococcal species in postoperative wound infection.     

Follow-up of renal and mesenteric artery revascularization with duplex ultrasonography

Objective

To evaluate the long-term anatomic results of renal revascularization procedures using duplex ultrasonography.

Design

A case series.

Setting

A university-affiliated hospital.

Patients

Twenty-five patients who had undergone renal percutaneous transluminal angioplasty (PTA) (18 arteries), renal bypass (10 arteries) and mesenteric bypass (6 arteries). The mean follow-up was 22 months (range from 3 to 48 months) for those who underwent renal PTA, 23 months (range from 1.5 to 70 months) for those who underwent renal bypass and 34 months (range from 8 to 144 months) for those who underwent mesenteric bypass.

Main Outcome Measures

Patency rates for the three procedures as assessed by duplex ultrasonography.

Results

Duplex ultrasonography demonstrated patency without stenosis after renal and mesenteric artery revascularization in 14 arteries subjected to renal PTA, 9 arteries subjected to renal bypass and 6 arteries subjected to mesenteric bypass. Three arteries that had renal PTA had recurrent vessel stenosis and one had occlusion. One artery that had renal bypass showed occlusion.

Conclusions

Renal PTA, renal bypass and mesenteric bypass are durable procedures at 2 years of follow-up, and duplex ultrasonography is a valuable method for assessing the patency of arteries after renal and mesenteric revascularization.     

Cardiopulmonary bypass increases the risk of vasoplegic syndrome after coronary artery bypass grafting in patients with dialysis-dependent chronic renal failure

Objective

Coronary artery bypass grafting is currently the best treatment for dialysis patients with multivessel coronary artery involvement. Vasoplegic syndrome of inflammatory etiology constitutes an important postoperative complication, with highly negative impact on prognosis. Considering that these patients have an intrinsic inflammatory response exacerbation, our goal was to evaluate the incidence and mortality of vasoplegic syndrome after myocardial revascularization in this group.

Methods

A retrospective, single-center study of 50 consecutive and non-selected dialysis patients who underwent myocardial revascularization in a tertiary university hospital, from 2007 to 2012. The patients were divided into 2 groups, according to the use of cardiopulmonary bypass or not (off-pump coronary artery bypass). The incidence and mortality of vasoplegic syndrome were analyzed. The subgroup of vasoplegic patients was studied separately.

Results

There were no preoperative demographic differences between the cardiopulmonary bypass (n=20) and off-pump coronary artery bypass (n=30) group. Intraoperative data showed a greater number of distal coronary arteries anastomosis (2.8 vs. 1.8, P<0.0001) and higher transfusion rates (65% vs. 23%, P=0.008) in the cardiopulmonary bypass group. Vasoplegia incidence was statistically higher (P=0.0124) in the cardiopulmonary bypass group (30%) compared to the off-pump coronary artery bypass group (3%). Vasoplegia mortality was 50% in the cardiopulmonary bypass group and 0% in the off-pump coronary artery bypass group. The vasoplegic subgroup analysis showed no statistically significant clinical differences.

Conclusion

Cardiopulmonary bypass increased the risk for developing postoperative vasoplegic syndrome after coronary artery bypass grafting in patients with dialysis-dependent chronic renal failure.     

Triple coronary artery revascularization on the stabilized beating heart: initial experience

Objective

To decrease health costs and morbidity related to extracorporeal circulation, surgeons have modified the coronary artery bypass (CAB) technique so that it can be completed without the use of extra-corporeal circulation. This study summarizes initial experience with direct coronary artery revascularization on the beating heart using a coronary stabilizer.

Design

A case series.

Setting

The Montreal Heart Institute, a university-affiliated centre, specializing in the treatment of cardiac illnesses.

Patients

Ten patients underwent CAB by this technique. They presented with double or triple coronary artery disease with no intramyocardial, heavily calcified, diffused atheromatous coronary vessels, or left main coronary disease.

Intervention

CAB grafting in the beating heart. The anterior wall was grafted in all patients, the inferior wall in 7 and the posterior wall in 7.

Main outcome measures

Patient survival and graft patency.

Results

One patient died of multiple organ failure not related to the grafting technique itself, and 1 patient suffered a non-Q myocardial infarction. Early coronary angiography performed on 8 patients showed 100% graft patency, most with excellent distal runoff (21/22 grafts).

Conclusion

In patients with adequate anatomy, performance of CAB without extracorporeal circulation can achieve excellent early results provided there is appropriate mechanical stabilization of the beating heart.     

EuroSCORE II and the importance of a local model,InsCor and the future SP-SCORE

Introduction

The most widely used model for predicting mortality in cardiac surgery was recently remodeled, but the doubts regarding its methodology and development have been reported.

Objective

The aim of this study was to assess the performance of the EuroSCORE II to predict mortality in patients undergoing coronary artery bypass grafts or valve surgery at our institution.

Methods

One thousand consecutive patients operated on coronary artery bypass grafts or valve surgery, between October 2008 and July 2009, were analyzed. The outcome of interest was in-hospital mortality. Calibration was performed by correlation between observed and expected mortality by Hosmer Lemeshow. Discrimination was calculated by the area under the ROC curve. The performance of the EuroSCORE II was compared with the EuroSCORE and InsCor (local model).

Results

In calibration, the Hosmer Lemeshow test was inappropriate for the EuroSCORE II (P=0.0003) and good for the EuroSCORE (P=0.593) and InsCor (P=0.184). However, the discrimination, the area under the ROC curve for EuroSCORE II was 0.81 [95% CI (0.76 to 0.85), P<0.001], for the EuroSCORE was 0.81 [95% CI (0.77 to 0.86), P<0.001] and for InsCor was 0.79 [95% CI (0.74-0.83), P<0.001] showing up properly for all.

Conclusion

The EuroSCORE II became more complex and resemblance to the international literature poorly calibrated to predict mortality in patients undergoing coronary artery bypass grafts or valve surgery at our institution. These data emphasize the importance of the local model.     

Association of Angiotensin-Converting Enzyme Genotype, Insertion/Deletion Polymorphism and Saphenous Vein Graft Atherosclerosis in Iranian Patients

OBJECTIVE

The aim of this study was to evaluate possible interactions among Angiotensin-I converting enzyme genotype, insertion/deletion polymorphism and atherosclerosis of vein grafts in Iranian patients, and characterize their clinical and demographic profile.

METHODS

In this cross-sectional study, patients who underwent coronary artery bypass graft surgery more than five years ago, were included for angiographic analysis. Atherosclerosis was determined by quantitative angiography and adjusted Gensini score. The gene angiotensin converting enzyme I/D polymorphism was detected by polymerase chain reaction.

RESULTS

A total of 102 patients participated in this study. Eighty-four patients were male. The frequency distribution of DD, ID and II polymorphism were 23.6%, 62.7% and 13.7% respectively. There were no differences among genotypic groups in age, sex, number of risk factors, number of vein grafts and months since bypass surgery. According to adjusted Gensini score [0.18±0.12 (II) vs. 0.11±0.09 (ID) and 0.1±0.09 (DD) P=0.021] the II genotype was associated with severity of vein graft atherosclerosis.

CONCLUSION

Although there are conflicting results about gene angiotensin converting enzyme I/D polymorphism and the degree of venous bypass graft degeneration, this study suggests an association between ACE genotype II and atherosclerosis of saphenous vein grafts, however, large samples considering clinical, demographic and ethnic profile are necessary to confirm these results.