What is the impact of endoscopic vein harvesting on clinical outcomes following coronary artery bypass graft surgery?

Objective Endoscopic vein harvesting (EVH) is increasingly used as an alternative to open vein harvesting (OVH) for coronary artery bypass graft (CABG) surgery. Concerns about the safety of EVH with regard to midterm clinical outcomes following CABG have been raised. The objective of this study was to assess the impact of EVH on short-term and midterm clinical outcomes following CABG. Design This was a retrospective analysis of prospectively collected multi-centre data. A propensity score was developed for EVH and used to match patients who underwent EVH to those who underwent OVH. Setting Blackpool Victoria Hospital, Plymouth Derriford Hospital and the University Hospital of South Manchester were the main study settings. Patients There were 4709 consecutive patients who underwent isolated CABG using EVH or OVH between January 2008 and July 2010. Main outcome measures The main outcome measure was a combined end point of death, repeat revascularisation or myocardial infarction. Secondary outcome measures included in-hospital morbidity, in-hospital mortality and midterm mortality. Results Compared to OVH, EVH was not associated with an increased risk of the main outcome measure at a median follow-up of 22 months (HR 1.15; 95% CI 0.76 to 1.74). EVH was also not associated with an increased risk of in-hospital morbidity, in-hospital mortality (0.9% vs 1.1%, p=0.71) or midterm mortality (HR 1.04; 95% CI 0.65 to 1.66). Conclusions This multi-centre study demonstrates that at a median follow-up of 22 months, EVH was not associated with adverse short-term or midterm clinical outcomes. However, before the safety of EVH can be clearly determined, further analyses of long-term clinical outcomes are required.

Donor heart selection: Wythenshawe experience.

BACKGROUND: The decline in the number of suitable donor hearts has led to an increasing interest in the use of previously unacceptable donors. This study aimed to evaluate the outcome of recipients of donor hearts considered medically unsuitable for transplantation at this center that were used in other centers in the United Kingdom. METHODS: Forty donor hearts (group 1) were declined by Wythenshawe Hospital and used in other units in the United Kingdom in the period extending from April 1998 to March 2003. One hundred four hearts (group 2) were transplanted at Wythenshawe Hospital during the same period. Donors and recipient data were obtained from the United Kingdom Cardiothoracic Transplant Audit database. Mortality in both groups was analyzed using SPSS software. RESULTS: Mortality in patients receiving grafts from group 1 donors was significantly higher than in group 2 (P < .0009). Of the early deaths in this group 50% (6 of 12) were the result of graft failure. These donors were receiving high doses of inotropes, had ischemic time exceeding 3.5 hours, and the grafts were transplanted into high-risk patients. CONCLUSION: Hearts declined on medical grounds by one center should be evaluated with caution before being considered suitable for transplantation, especially when more than one adverse factor is present.

Orthotopic heart transplantation in a transgenic pig-to-primate model.

BACKGROUND: Previous studies demonstrated that hearts from transgenic pigs expressing human decay-accelerating factor (hDAF) were not hyperacutely rejected when transplanted heterotopically into the abdomen of cynomolgus monkeys. This study examines orthotopic transplantation of hDAF transgenic pig hearts into baboon recipients. METHODS: Orthotopic xenogeneic heart transplantation was performed using piglets, transgenic for hDAF, as donors. Ten baboons were used as recipients and were immunosuppressed with a combination of cyclophosphamide, cyclosporine, and steroids. RESULTS: Five grafts failed within 18 hr without any histological signs of hyperacute rejection. Pulmonary artery thrombosis induced by a size mismatch was observed in two of these animals. The other three recipients died because of failure to produce even a low cardiac output and/or dysrhythmia. The remaining five animals survived between four and nine days. One animal died of bronchopneumonia on day 4. Three xenografts stopped beating on day 5 due to acute vascular rejection. The longest survivor was killed on day 9 with a beating, histologically normal xenograft, because of pancytopenia. CONCLUSIONS: The results reported here demonstrate that hDAF transgenic pig hearts are not hyperacutely rejected when transplanted into baboon recipients. Orthotopically transplanted transgenic pig hearts are capable of maintaining cardiac output in baboons. An optimum immunosuppressive regimen is the subject of ongoing research.

Life-supporting pig-to-primate renal xenotransplantation using genetically modified donors.

BACKGROUND: In order to circumvent the complement-mediated hyperacute rejection of discordant xenografts, a colony of pigs transgenic for the human regulator of complement activity, human decay-accelerating factor (hDAF), has been produced. METHODS: Seven kidneys from hDAF transgenic pigs and six kidneys from nontransgenic control pigs were transplanted into cynomolgus monkeys; both native kidneys were removed during the same operation. The recipient animals were immunosuppressed with cyclosporine, steroids, and cyclophosphamide. RESULTS: In the transgenic group, the median survival time was 13 days (range, 6-35 days); the median survival time in the control group was 6.5 days (range, 0.3-30 days). There were no cases of hyperacute rejection in the transgenic group, and the two longest-surviving kidneys in this group showed no evidence of rejection on histological examination. In contrast, all control kidneys underwent antibody-mediated rejection, one demonstrating hyperacute rejection and the others acute vascular rejection. CONCLUSION: This study demonstrates that (i) a kidney from an hDAF transgenic pig can support the life of a primate for up to 35 days (and also shows the basic physiological compatibility between the pig and nonhuman primate); (ii) nontransgenic kidneys are not routinely hyperacutely rejected; and (iii) the presence of hDAF on the kidney confers some protection against acute vascular rejection. Improved immunosuppression and immunological monitoring may enable extended survival.

Life-supporting pig-to-baboon heart xenotransplantation.

BACKGROUND: The aim of this study was to investigate the effect of the expression of human decay-accelerating factor in transgenic pigs on hyperacute rejection in a pig-to-baboon heterotopic heart transplantation model and to assess the ability of such transgenic pig hearts in supporting the life of a primate when transplanted orthotopically. METHODS: Hearts from pigs transgenic for human decay-accelerating factor were transplanted heterotopically (n = 3) and orthotopically (n = 5) into the baboon. All animals received cyclosporine, steroids, and cyclophosphamide. Blood was sampled regularly for total antipig antibody titers, trough cyclosporine levels, full blood count, electrolytes, and creatinine. Rejection of the heterotopic hearts was defined as the absence of palpable cardiac pulsation. Explanted hearts were examined histologically with hematoxylin and eosin and with immunochemistry for complement components C3, C4, C9, and immunoglobulin M. RESULTS: None of the hearts were hyperacutely rejected. In the heterotopic group one heart underwent acute vascular rejection on day 13, and the remaining two recipients with beating xenografts were killed on days 2 and 21. In the orthotopic group, one recipient with a life-supporting xenograft was killed on day 9 because of poor general condition. Histologic examination demonstrated no evidence of rejection. Two xenografts stopped beating on day 5, and histologic study showed acute vascular rejection in both. There were also two graft failures for technical reasons in this group. CONCLUSIONS: Hyperacute rejection is abrogated in pig-to-baboon heart xenotransplantation with the expression of the human decay-accelerating factor transgene. The human decay-accelerating factor transgenic pig heart is able to support primate life for a prolonged period.

Thoracoscopic bullectomy and tetracycline pleurodesis for the treatment of spontaneous pneumothorax.

Initial experience of thoracoscopic bullectomy and tetracycline pleurodesis for the treatment of spontaneous pneumothorax is reported. Thirty-three out of 49 patients admitted with spontaneous pneumothorax were suitable for treatment with this minimally invasive method. This series demonstrates that this surgical management offers early discharge and return to normal activities with excellent medium-term results, despite the three early failures. It is felt that with increased experience in thoracoscopy and improved selection of patients, thoracoscopic bullectomy and pleurodesis will become the treatment of choice for primary spontaneous pneumothorax.

Early experience with the Toronto stentless porcine valve.

Stentless porcine valves in the aortic position offer many theoretic advantages, but their clinical performance has not been adequately defined. We evaluated the clinical and echocardiographic results of 103 patients who had aortic valve replacement with the Toronto stentless porcine valve over a 2-year period. There were 67 men with a mean age of 68 years. The predominant native valve lesion was aortic stenosis (64%), and 4 patients had prosthetic valve dysfunction. Forty-two patients had concomitant procedures. The 30-day mortality rate was 3.3% (n = 2) for isolated valve replacement and 5.8% (n = 6) for the series. The sole determinant of early death was poor left ventricular function. There were three late deaths due to non-valve-related complications over a median follow-up of 11.87 months. In addition, prosthetic valve endocarditis developed in 1 patient, necessitating a homograft valve replacement at 6 weeks. Doppler echocardiography performed at 3 to 6 months showed low peak and mean transvalvular gradients, with no substantial change at 1 year. None of the patients showed signs of clinically significant aortic regurgitation, although echocardiography demonstrated trivial or mild regurgitation in 12 patients at discharge or early follow-up, which was less marked or absent at 1 year. We conclude that the Toronto stentless porcine valve appears to offer promising early results.

Avulsion of short gastric arteries caused by vomiting.

A case is presented describing a new, potentially life threatening complication of vomiting after a 21 year old man presented in shock with a haemoperitoneum caused by violent, self induced emesis.

The relative strengths of the rotator cuff muscles. A cadaver study.

We studied five cadaver shoulders to determine the strength relationship of the four rotator cuff muscles. The mean fibre length and volume of each muscle were measured, from which the physiological cross-sectional area was calculated. This value was used to estimate the force which each muscle was capable of generating. The lever arm of each muscle about the humeral head was then measured and the moment exerted was calculated. The strength ratios between the muscles were more or less constant in the five specimens. Subscapularis was the most powerful muscle and contributed 53% of the cuff moment; supraspinatus contributed 14%, infraspinatus 22% and teres minor 10%. The force-generating capacity of the subscapularis was equal to that of the other three muscles combined.

Sensitivity tests with cephalosporins.

The sensitivity of 127 strains of miscellaneous Gram-negative bacilli to various cephalosporins was determined by three methods. Disc tests with cephaloridine (CLOR), cephalothin (CTIN) and cephalexin (CLEX) made most strains of beta-lactamase-producing Escherichia coli appear sensitive. Eight cephalosporins were tested by the agar break-point method using concentrations of 16 and 4 mg/l for all except cefotaxime (CTAX), when 8 and 1 mg/l were used. In repeated tests there was considerable variation in the response of many strains to the lower concentration of CLOR, CTIN, CLEX and to a lesser extent, cefoxitin (CFOX) and cefuroxime (CROX), and beta-lactamase-producing E coli appeared as sensitive or moderately sensitive to all. Cephalosporins CLOR, CLEX, and CROX were then tested by inoculating 2 ml volumes of broth containing a 30 microgram disc; all the beta-lactamase-producing E coli grew in CLOR and CLEX but were inhibited by CROX.

Penetration of penicillin into the cerebrospinal fluid of patients with latent syphilis.

Eighteen patients with latent syphilis were treated with 360 mg, 720 mg, 1080 mg or 1440 mg intramuscular procaine penicillin daily for 14 days. Penicillin was assayed in serum and cerebrospinal fluid collected 3 hours after the second injection in each patient. Penicillin was present in all sera in concentrations greater than the generally accepted fully treponemacidal level, but none was detected in cerebrospinal fluid from 11 patients. The significance of these results is discussed, particularly with a view to changes in standard treatment regimens for latent syphilis.

A problem with the recognition of penicillin-resistant pneumococci.

A strain of Streptococcus pneumoniae requiring 0.25 mg/1 penicillin to inhibit its growth was isolated from the antrum of a child who had no history of either foreign contacts or previous treatment with penicillin. The penicillin resistance was recognised by chance because the disc used contained substantially less than its stated content of 1.5 unit. When discs containing 2 units were used there was little reduction in size of the zone of inhibition.

An evaluation of the Replireader in the identification of Enterobacteriaceae isolated from urine and in the recording of sensitivity tests performed by an agar dilution method.

In the Replireader system for identifying Enterobacteriaceae, plates of biochemical media are inoculated with a replicator and the results are put into a computer. The machine correctly identified 92x2% of 734 strains of Gram-negative bacilli isolated from urine; it was incorrect in 0x8% and failed to recognise 7%. The Replireader was also used to record the results of sensitivity tests using a plate dilution method in which the drugs were provided by impregnated filter papers (Adapads).