Development and internal validation of a model for postoperative morbidity in adults undergoing major elective colorectal surgery: the peri-operative quality improvement programme (PQIP) colorectal risk model

Over 1.5 million major surgical procedures take place in the UK NHS each year and approximately 25% of patients develop at least one complication. The most widely used risk-adjustment model for postoperative morbidity in the UK is the physiological and operative severity score for the enumeration of mortality and morbidity. However, this model was derived more than 30 years ago and now overestimates the risk of morbidity. In addition, contemporary definitions of some model predictors are markedly different compared with when the tool was developed. A second model used in clinical practice is the American College of Surgeons National Surgical Quality Improvement Programme risk model; this provides a risk estimate for a range of postoperative complications. This model, widely used in North America, is not open source and therefore cannot be applied to patient populations in other settings. Data from a prospective multicentre clinical dataset of 118 NHS hospitals (the peri-operative quality improvement programme) were used to develop a bespoke risk-adjustment model for postoperative morbidity. Patients aged ≥ 18 years who underwent colorectal surgery were eligible for inclusion. Postoperative morbidity was defined using the postoperative morbidity survey at postoperative day 7. Thirty-one candidate variables were considered for inclusion in the model. Death or morbidity occurred by postoperative day 7 in 3098 out of 11,646 patients (26.6%). Twelve variables were incorporated into the final model, including (among others): Rockwood clinical frailty scale; body mass index; and index of multiple deprivation quintile. The C-statistic was 0.672 (95%CI 0.660-0.684), with a bootstrap optimism corrected C-statistic of 0.666 at internal validation. The model demonstrated good calibration across the range of morbidity estimates with a mean slope gradient of predicted risk of 0.959 (95%CI 0.894-1.024) with an index-corrected intercept of -0.038 (95%CI -0.112-0.036) at internal validation. Our model provides parsimonious case-mix adjustment to quantify risk of morbidity on postoperative day 7 for a UK population of patients undergoing major colorectal surgery. Despite the C-statistic of < 0.7, our model outperformed existing risk-models in widespread use. We therefore recommend application in case-mix adjustment, where incorporation into a continuous monitoring tool such as the variable life adjusted display or exponentially-weighted moving average-chart could support high-level monitoring and quality improvement of risk-adjusted outcome at the population level.

The influence of anastomotic techniques on postoperative anastomotic complications: Results of the Oesophago-Gastric Anastomosis Audit

BACKGROUND

The optimal anastomotic techniques in esophagectomy to minimize rates of anastomotic leakage and conduit necrosis are not known. The aim of this study was to assess whether the anastomotic technique was associated with anastomotic failure after esophagectomy in the international Oesophago-Gastric Anastomosis Audit cohort.

METHODS

This prospective observational multicenter cohort study included patients undergoing esophagectomy for esophageal cancer over 9 months during 2018. The primary exposure was the anastomotic technique, classified as handsewn, linear stapled, or circular stapled. The primary outcome was anastomotic failure, namely a composite of anastomotic leakage and conduit necrosis, as defined by the Esophageal Complications Consensus Group. Multivariable logistic regression modeling was used to identify the association between anastomotic techniques and anastomotic failure, after adjustment for confounders.

RESULTS

Of the 2238 esophagectomies, the anastomosis was handsewn in 27.1%, linear stapled in 21.0%, and circular stapled in 51.9%. Anastomotic techniques differed significantly by the anastomosis sites (P < .001), with the majority of neck anastomoses being handsewn (69.9%), whereas most chest anastomoses were stapled (66.3% circular stapled and 19.3% linear stapled). Rates of anastomotic failure differed significantly among the anastomotic techniques (P < .001), from 19.3% in handsewn anastomoses, to 14.0% in linear stapled anastomoses, and 12.1% in circular stapled anastomoses. This effect remained significant after adjustment for confounding factors on multivariable analysis, with an odds ratio of 0.63 (95% CI, 0.46-0.86; P = .004) for circular stapled versus handsewn anastomosis. However, subgroup analysis by anastomosis site suggested that this effect was predominantly present in neck anastomoses, with anastomotic failure rates of 23.2% versus 14.6% versus 5.9% for handsewn versus linear stapled anastomoses versus circular stapled neck anastomoses, compared with 13.7% versus 13.8% versus 12.2% for chest anastomoses.

CONCLUSIONS

Handsewn anastomoses appear to be independently associated with higher rates of anastomotic failure compared with stapled anastomoses. However, this effect seems to be largely confined to neck anastomoses, with minimal differences between techniques observed for chest anastomoses. Further research into standardization of anastomotic approach and techniques may further improve outcomes.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Textbook outcome following oesophagectomy for cancer: international cohort study

Background

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

Methods

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

Results

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter ‘no major postoperative complication’ had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P &lt; 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P &lt; 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

Conclusion

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Textbook outcome following oesophagectomy for cancer: international cohort study

BACKGROUND

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

METHODS

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

RESULTS

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter 'no major postoperative complication' had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

CONCLUSION

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND

The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting.

METHODS

Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups.

RESULTS

Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005).

CONCLUSION

Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.

Mortality from esophagectomy for esophageal cancer across low, middle, and high-income countries: An international cohort study

BACKGROUND

No evidence currently exists characterising global outcomes following major cancer surgery, including esophageal cancer. Therefore, this study aimed to characterise impact of high income countries (HIC) versus low and middle income countries (LMIC) on the outcomes following esophagectomy for esophageal cancer.

METHOD

This international multi-center prospective study across 137 hospitals in 41 countries included patients who underwent an esophagectomy for esophageal cancer, with 90-day follow-up. The main explanatory variable was country income, defined according to the World Bank Data classification. The primary outcome was 90-day postoperative mortality, and secondary outcomes were composite leaks (anastomotic leak or conduit necrosis) and major complications (Clavien-Dindo Grade III - V). Multivariable generalized estimating equation models were used to produce adjusted odds ratios (ORs) and 95% confidence intervals (CI95%).

RESULTS

Between April 2018 to December 2018, 2247 patients were included. Patients from HIC were more significantly older, with higher ASA grade, and more advanced tumors. Patients from LMIC had almost three-fold increase in 90-day mortality, compared to HIC (9.4% vs 3.7%, p < 0.001). On adjusted analysis, LMIC were independently associated with higher 90-day mortality (OR: 2.31, CI95%: 1.17-4.55, p = 0.015). However, LMIC were not independently associated with higher rates of anastomotic leaks (OR: 1.06, CI95%: 0.57-1.99, p = 0.9) or major complications (OR: 0.85, CI95%: 0.54-1.32, p = 0.5), compared to HIC.

CONCLUSION

Resections in LMIC were independently associated with higher 90-day postoperative mortality, likely reflecting a failure to rescue of these patients following esophagectomy, despite similar composite anastomotic leaks and major complication rates to HIC. These findings warrant further research, to identify potential issues and solutions to improve global outcomes following esophagectomy for cancer.

Changing picture of acute kidney injury in pregnancy: Study of 259 cases over a period of 33 years

The incidence of acute kidney injury (AKI) in pregnancy is declining in developing countries but still remains a major cause of maternal and fetal morbidity and mortality. The aim of the study was to analyze the changing trends in pregnancy related AKI (PR-AKI) over a period of thirty-three years. Clinical characteristics of PR-AKI with respect to incidence, etiology and fetal and maternal outcomes were compared in three study periods, namely 1982-1991,1992-2002 and 2003-2014. The incidence of PR-AKI decreased to 10.4% in 1992-2002, from 15.2% in 1982-1991, with declining trend continuing in 2003-2014 (4.68%).Postabortal AKI decreased to 1.49% in 2003-2014 from 9.4% in 1982-1991of total AKI cases. The AKI related to puerperal sepsis increased to 1.56% of all AKI cases in 2003-2014 from 1.4% in 1982-1991. Preeclampsia/eclampsia associated AKI decreased from 3.5% of total AKI cases in 1982-1991 to 0.54% in 2003-2014. Pregnancy associated – thrombotic microangiopathy and acute fatty liver of pregnancy were uncommon causes of AKI. Hyperemesis gravidarum associated AKI was not observed in our study. Incidence of renal cortical necrosis (RCN) decreased to 1.4% in 2003-2014 from 17% in 1982-1991.Maternal mortality reduced to 5.79% from initial high value 20% in 1982-1991. The progression of PR-AKI to ESRD decreased to1.4% in 2003-2014 from 6.15% in 1982-1991. The incidence of PR-AKI has decreased over last three decades, mainly due to decrease in incidence of postabortal AKI. Puerperal sepsis and obstetric hemorrhage were the major causes of PR-AKI followed by preeclampsia in late pregnancy. Maternal mortality and incidence and severity of RCN have significantly decreased in PR-AKI. The progression to CKD and ESRD has decreased in women with AKI in pregnancy in recent decade. However, the perinatal mortality did not change throughout study period.

Surgical outcomes of minimally invasive vitrectomy surgery in Eales' disease

INTRODUCTION

The results of surgical outcomes of 20 gauge pars plana vitrectomy in Eales' disease are available in the scientific literature. However, all these studies have been done using the 20 gauge vitrectomy systems and most studies have been conducted in a retrospective manner.

OBJECTIVE

To evaluate the outcomes and safety of 23 gauge vitrectomy in complications of Eales' disease.

MATERIALS AND METHODS

STUDY DESIGN

Consecutive interventional case series.

PARTICIPANTS

Seventy-six eyes of 72 nonconsecutive patients undergoing 23-gauge vitrectomy for complications of Eales' disease were enrolled. The participants were followed up for a minimum of one year.

INTERVENTION

The participants underwent a complete demographic, medical and ophthalmic evaluation. A 23-gauge vitrectomy was performed. Endotamponade was used when necessary. Perioperative and postoperative events were recorded. Primary outcome measures were visual acuity and complications arising due to surgery.

RESULTS

Indication for surgery was non-clearing vitreous hemorrhage in 89.4% (68/76) and secondary retinal detachment in 10.6% (8). Visual acuity improved from Log Mar 1.80 ± 0.19 units preoperatively to Log Mar 0.47±0.59. Best-corrected visual acuity equivalent to Snellen 6/9 was achieved in 77. 6% of eyes. . Surgical failure was seen in 6.5% cases. Four cases were lost due to progression to neovascular glaucoma and 1 case was lost to severe residual retinal detachment. Iatrogenic portside retinal breaks occurred in 3.9% (3), post-vitrectomy retinal detachment 2.6% ( 2), hypotony 1.3% (1) and cataract in 38.1% (28) cases.

CONCLUSION

23-gauge sutureless vitrectomy in patients with Eales' disease is a safe and effective technique with acceptable level of risk and complications.

Serious adverse effects from single-use detergent sacs: report from a U.S. statewide poison control system

BACKGROUND

In recent years, serious adverse effects to children from exposure to single-use detergents sacs (SUDS) have been recognized. While most exposures result in minor symptoms, there have been serious outcomes. This study aims to classify which types of serious outcomes follow SUDS exposures, and to assess, if possible, differences in toxicity between various SUDS products.

METHODS

An observational case series with data collected retrospectively was performed for cases of SUDS exposures reported to a statewide poison system's records database from 1 January 2012 to 31 March 2013. Cases were identified and analyzed for clinical details and trends. A statewide database was queried for cases involving the American Association of Poison Control Centers (AAPCC) product-specific codes for SUDS products using following search terms: laundry pods, the AAPCC product-specific codes for Tide Pods, Purex Ultrapacks, ALL Mighty Pacs, and a unique agent code (AAPCC ID: 6903138; Generic: 077900) created by AAPCC to track SUDS exposures.

RESULTS

A total of 804 cases of exposures to SUDS were identified, the majority of which were exploratory ingestions in young children with a median age of 2 years. Serious adverse effects resulted from 65 (9%) exposures and 27 (3%) exposures resulted in admission to hospital. Binary logistic regression demonstrated that the presence of central nervous system (CNS) or respiratory system effects were associated with more severe outcomes, with a model accuracy of 96.4%. There were significant differences in morbidity among the three most common brand-name products: when compared with Tide Pods, odds ratios (OR) and 95% confidence intervals (CI) for severe outcome and admission rate were significantly greater following Purex Ultrapack exposures (severity OR 5.1 [CI: 2.13-12.23]; admission OR 10.36 [CI: 3.23-33.22]) and ALL Mighty Pac exposures (severity OR 11.22 [CI: 4.78-28.36]; admission OR 15.20 [CI: 5.01-46.12]).

CONCLUSIONS

Serious complications from exposure to SUDS occur in a small number of exposures for unclear reasons. Respiratory and CNS effects are associated with more severe outcomes. Some brand-name products are associated with a relatively higher risk of severe adverse effects and rates of admission.

Lower limb ischaemic symptoms in the young patient: popliteal artery entrapment

This case report describes a case of Popliteal Entrapment Syndrome causing unilateral ischaemic claudication symptoms in an otherwise healthy soldier. The condition is rare but is an important cause of exercise related leg pain; untreated it can progress to structural arterial damage requiring reconstruction. Early identification of such cases may allow less invasive treatment.

Subclinical peripheral neuropathy in stable middle-aged patients with chronic obstructive pulmonary disease

INTRODUCTION

Presently, there are few studies addressing the subject of peripheral neuropathy in patients with chronic obstructive pulmonary disease (COPD). Consequently, there is a dearth of evidence and awareness of subclinical neuropathy in stable COPD patients with no significant hypoxaemia, particularly in the age group of 40-60 years. The present study was designed to evaluate the subclinical peripheral neuropathy in this study group.

METHODS

60 subjects were included in the study. The COPD group comprised 30 male smokers with stable COPD, aged between 40 and 60 years and with no clinical neuropathy; and 30 age-matched healthy male volunteers served as the control group. The following nerves were evaluated for latency, amplitude and conduction velocity: for motor nerve conduction - median nerve, ulnar nerve, and common peroneal nerves; and for sensory nerve conduction - median nerve, ulnar nerve, and sural nerves.

RESULTS

Five out of 30 COPD patients had peripheral nerve impairment on electrophysiological evaluation. In these patients, we found decreased amplitude and conduction velocity in all examined sensory nerves; however, the conduction velocity was found to be more than 70 percent of the predicted value. These findings were suggestive of predominantly sensory (with milder involvement of motor nerves) axonal polyneuropathy.

CONCLUSION

We observed five out of 30 COPD patients to have predominantly sensory axonal peripheral neuropathy. These five COPD patients had significantly higher consumption of cigarettes, longer duration of illness and advanced airflow obstruction when compared to COPD patients with no peripheral neuropathy.

Acute renal failure in the intensive care unit

BACKGROUND

Acute renal failure (ARF) in the intensive care unit (ICU) is associated with high mortality. A thorough understanding of the clinical spectrum of the disease is needed in order to devise methods to improve the final outcome due to this problem.

AIMS AND OBJECTIVES

The aim of the present study was to analyze the clinical spectrum, causes, risk and prognostic factors and final outcome of ARF in the setting of ICU.

METHOD

This prospective study involved patients admitted to ICU during the period between September 2003 to January 2005 (17 months). Patients who developed ARF during the ICU stay were included in the study. The clinical and laboratory data were collected at admission and then on daily basis. Data recorded included; patient characteristics, underlying medical conditions responsible for ICU admission, dialytic status, need for ventilation, total duration of ICU stay, APACHE-III score and final outcome, and these data were analyzed for predicting survival using univariate and multivariate analysis.

RESULTS

Twelve hundred and fifteen (1215) patients were admitted to ICU from September 2003 to January, 2005 and 46 (3.79%) patients developed ARF after admission to ICU. Mean age of patients was 44.9 +/- 17 years and 56.5% were males. Comorbidity was seen in 24 (52%) patients; hypertension (34.7%), diabetes mellitus (28.3%), coronary artery disease (30.4%) and chronic kidney disease (13%). ARF had developed complicating medical and surgical conditions in 33 (71.7%) and 11 (23.7%) patients respectively. The etiology of ARF was multifactorial and included; hypotension (71.74%), volume depletion (17.4%), nephrotoxic drugs (67.39%), and sepsis (69.5%). Multiple organ system failure (MOSF) was noted in 63% of cases and dialysis was required in 25 (54.3%) patients. Mortality occurred in 63% of patients. MOSF and sepsis were found to be significant adverse prognostic factors when multiple logistic regression analysis was done.

CONCLUSIONS

ARF was seen in 3.79% of cases in our ICU and associated with poor prognosis. Presence of sepsis, MOSF, higher APACHE--III scores and ventilation need were correlated with higher mortality in ARF patients in the intensive care unit.

Novel PCR-EIA method for the detection of Chlamydia pneumoniae in respiratory specimens

We report the development of a microtitre plate-based PCR-EIA assay (ELAHA; Enzyme Linked Amplification and Hybridization Assay) for the sensitive and specific detection of Chlamydia pneumoniae in sputum samples from patients with chronic obstructive airways disease (COAD). Following PCR amplification of a segment of the chlamydial heat shock 60 protein gene, the 587 bp sized amplicon is captured onto the streptavidin coated surface of a microtitre plate using a C. pneumoniae specific biotinylated probe and the level of captured product is subsequently determined via a colorimetric reaction using an automated plate reader. The ELAHA is a simple, rapid and inexpensive method for detection of low levels of infectious agents and is readily adaptable to current clinical laboratory equipment. The assay was evaluated with a cohort of hospital respiratory patients: (i) COAD patients with acute exacerbation, (ii) COAD patients without exacerbation (stable) and (iii) a non-respiratory control group. The ELAHA produced 6/12 (50%) C. pneumoniae positives in the COAD with exacerbation group, 3/13 (23%) positives in the COAD without exacerbation group and only 1/6 (17%) positives in the control non-respiratory group. This sensitive and robust PCR-EIA method can provide clinically relevant diagnostic evidence of current C. pneumoniae infection contributing to serious respiratory tract diseases such as COAD.

Gelatine-resorcine-formol glue as a sealant of ePTFE patch suture lines

BACKGROUND

ePTFE patch reconstruction has superior flow characteristics in preventing early thrombus formation during carotid endarterectomy. However prolonged bleeding at the suture line of the patch reconstruction is a problem. The aim of this study was to investigate whether the application of gelatine-resorcine-formol (GRF) glue at the suture line can improve local haemostasis.

METHODS

A prospective randomised trial of 40 consecutive patients undergoing carotid endarterectomy was undertaken. Patients were randomised to receive GRF glue as a topical haemostatic agent or to act as controls. Statistical analysis was performed using the Mann-Whitney test.

RESULTS

Although the patch size was significantly smaller in the control group (3.0 cm2 vs 4.3 cm2, p<0.001), local haemostasis was achieved in half the time when the glue was used (11 min vs 22, p<0.004). In the follow-up period ranging from 12 to 24 months, there have been no adverse effects related to the glue. Two patients died during the follow-up period. These deaths were neither related to the patch nor to the glue.

CONCLUSIONS

This study has shown that GRF glue is an effective sealant of ePTFE patch suture line. GRF glue does not compromise the patch's characteristics.

Worsening lipid profile is associated with progression of carotid artery stenosis

BACKGROUND

To determine if uncontrolled hypercholesterolaemia predisposes to progression of carotid artery stenosis.

METHODS

Fasting blood samples were collected from 76 patients referred for carotid duplex ultrasound for investigation of transient ischaemic attacks or recent stroke. Patients were grouped depending on the severity of the stenosis found. Patients on lipid lowering agents were excluded. The data were analysed using one way analysis of variance and the c2 test as appropriate.

RESULTS

There were more men in the 70-99% group (15 vs 6, c2 = 10.6, p < 0.001, Table I). The total cholesterol was raised in all three groups. Patients with carotid stenosis of 70-99% had significantly elevated triglycerides (2.4 mmol vs 1.47 mmol and 1.37 mmol, p < 0.003), low HDL (1.14 mmol vs 1.45 mmol and 1.18 mmol, p < 0.003) and a higher cholesterol/HDL ratio (5.56 vs 4.29 and 4.71, p < 0.014) compared with the other two groups. There was no difference in lipoprotein(a) in the three groups.

CONCLUSIONS

Increased triglycerides and low HDL cholesterol seen in the 70-99% group suggest that a worsening lipid profile is associated with progression of carotid artery stenosis.

Cure in a case of primary hepatic lymphoma

Primary hepatic lymphoma is rare malignancy. Cures in this disease are uncommon. We report a young male who was diagnosed as a case of primary lymphoma of the liver in 1992. He was treated with chemotherapy only, which included CHOP (Cyclophosphamide, Adriamycin, Vincristine and Prednisolone) - six cycles; and IMVP-16 (Ifosfamide, Methotrexate and Etoposide) -four cycles. The patient is now disease free and alive for more than five years.

Giant spinal arachnoid cysts: computed tomography, magnetic resonance imaging and magnetic resonance myelography correlation

Two cases of giant spinal arachnoid cysts, one of them being symptomatic, are discussed, along with their CT, MRI and MR myelography findings.

Management of heel pain syndrome with acetic acid iontophoresis

This study was undertaken to determine the effectiveness of acetic acid iontophoresis in the treatment of heel pain. Thirty-five patients with chronic heel pain were treated with acetic acid iontophoresis over a 4-year period. Ninety-four percent of patients had complete or substantial relief of heel pain after an average of 5.7 sessions of acetic acid iontophoresis over an average period of 2.8 weeks. Heel pain levels were rated from 0 to 10, with 10 representing the most severe pain. Heel pain prior to iontophoresis treatment received an average rating of 7.5; by the end of therapy, the average rating had decreased to 1.8. At an average follow-up time of 27 months, heel pain levels averaged 0.64, indicating continued reduction in heel pain. Ninety-four percent of participants said that they would recommend acetic acid iontophoresis to someone with similar heel pain.

Tuberculous osteomyelitis

Tuberculous osteomyelitis which does not involve a joint is uncommon and may fail to be diagnosed by an orthopaedic surgeon. We treated 28 lesions of tuberculous osteomyelitis in 25 patients between 1988 and 1995. The duration of symptoms was from two to 39 months, and most of our patients had been treated initially with non-steroidal anti-inflammatory drugs which failed to provide relief. Bone pain which does not promptly respond to analgesic medication is often due to infection or neoplasia. In the early stages, when plain radiographs are normal, MRI or CT may help to localise lesions. On plain radiographs, more advanced lesions may mimic chronic pyogenic osteomyelitis, Brodie's abscess, tumours or granulomatous lesions. Biopsy is mandatory to confirm the diagnosis, and antituberculous drugs are the mainstay of treatment. When operative findings at biopsy have the features of skeletal tuberculosis curettage of the affected bone may promote earlier healing.

TUBERCULOUS OSTEOMYELITIS

Tuberculous osteomyelitis which does not involve a joint is uncommon and may fail to be diagnosed by an orthopaedic surgeon. We treated 28 lesions of tuberculous osteomyelitis in 25 patients between 1988 and 1995. The duration of symptoms was from two to 39 months, and most of our patients had been treated initially with non-steroidal anti-inflammatory drugs which failed to provide relief. Bone pain which does not promptly respond to analgesic medication is often due to infection or neoplasia.

In the early stages, when plain radiographs are normal, MRI or CT may help to localise lesions. On plain radiographs, more advanced lesions may mimic chronic pyogenic osteomyelitis, Brodie’s abscess, tumours or granulomatous lesions. Biopsy is mandatory to confirm the diagnosis, and antituberculous drugs are the mainstay of treatment. When operative findings at biopsy have the features of skeletal tuberculosis curettage of the affected bone may promote earlier healing.

Endothelial cell seeding kinetics under chronic flow in prosthetic grafts

Improved patency of endothelial cell seeded grafts relies on good initial adherence and cell retention when the circulation is restored. In this study human adult endothelial cells (HAECs) were used to evaluate the suitability of commercially available prostheses for seeding. Acutely seeded indium-111 oxine labeled HAECs were used to measure cell adherence to plain and fibronectin (FN)-coated expanded polytetrafluoroethylene (ePTFE), gelatin-impregnated Dacron (Gelseal), and collagen-impregnated Dacron (Hemashield) grafts. Cell loss from FN-coated prostheses, when exposed to a simulated human arterial blood flow of 200 ml/min in an artificial pulsatile circulation, was quantified from the loss of gamma activity from the graft over 24 hours, pressure in the circulation being reduced to 15 mm Hg to reduce fluid loss. Initial HAEC adherence (mean [SD]) to plain grafts was 3(1)%, 47(9)%, and 53(9)% for ePTFE, Gelseal, and Hemashield, respectively. This improved significantly with FN coating (78[6]%, 60[8]%, and 76[4]%). Cell retention after 24 hours of flow to FN-coated grafts was 16(10)%, 25(5)%, and 65(4)% and was confirmed qualitatively by scanning electron microscopy and environmental scanning electron microscopy. FN significantly improved initial cell adherence with Dacron grafts showing the better adherence. Cell retention after 24 hours of flow was better with FN-coated Dacron than with ePTFE but was best with Hemashield grafts.

The relative effectiveness of estrone, estradiol-17 beta, and estriol in sex reversal in the red-eared slider (Trachemys scripta), a turtle with temperature-dependent sex determination

In many turtles the temperature during the middle of incubation determines the gonadal sex of the hatchling. Sex steroid hormones have been implicated in temperature-dependent sex determination in the red-eared slider turtle, Trachemys scripta; nonaromatizable androgens are involved in male sex determination and estrogens and aromatizable androgens in female sex determination. Administration of exogenous estradiol-17 beta to eggs incubating at a temperature that normally produces only males can overcome the effect of temperature and result in all offspring being female. Further, estradiol-17 beta and incubation temperature synergize to produce a greater feminizing effect at intermediate incubation temperatures that produce mixed sex ratios. This study demonstrates that, in the red-eared slider, there is a complex interaction between incubation temperature, different estrogens, and the dosage effect of each hormone. There are changes in potency of different estrogens with incubation temperature such that estriol is more potent than estrone and estradiol-17 beta at 26 degrees (an all-male producing incubation temperature), estrone and estriol are equipotent to each other and more potent than estradiol-17 beta at 28.8 degrees (an incubation temperature that produced a male-biased sex ratio), and estradiol-17 beta is more potent than estrone and estriol at 29 degrees (an incubation temperature that produced equal numbers of males and females). These changes may be due to differences in synergism between the hormones and incubation temperature. Estriol treatment also resulted in cranially hypertrophied oviducts at all incubation temperatures in a dose-dependent manner, whereas animals treated with estradiol-17 beta and estrone had normal oviducts. These results support the hypothesis that estrogens are involved in the final common pathway of female sex determination in this species.

Imaging in phaeohyphomycosis of the brain: case report

A case of multiple, conglomerated brain abscesses due to Xylohypha bantiana, with unique imaging features, is presented. This is the first culture-proven case of brain infection due to this fungus in the neuroimaging literature.

Tuberculosis of the elbow. A report of 10 cases

We treated 10 cases of tuberculosis of the elbow with a 9-month antitubercular drug regimen, and surgery when indicated. The diagnosis was confirmed in 8 cases by histopathological examination and 2 cases were treated on clinical radiographic grounds. The follow-up ranged from 1 year to 3 years. The results were excellent in synovial and extraarticular lesions. Only in cases with minimal involvement of articular cartilage was a good range of movement achieved.

Cerebral oxygen saturation, transcranial Doppler ultrasonography and stump pressure in carotid surgery

Transcranial Doppler ultrasonography (TCD) of the middle cerebral artery (MCA), light-reflective cerebral oximetry and measurement of internal carotid artery stump pressure were compared as methods of monitoring cerebral perfusion during carotid surgery in 33 patients. Median cerebral oxygen saturation was 70 (range 62-85) per cent and TCD-measured mean blood velocity 42 (range 19-91) cm/s before carotid cross-clamping, falling to 68 (53-83) per cent and 16 (0-50) cm/s respectively on application of the clamps (P < 0.001). Stump pressure correlated closely with MCA blood velocity 30 s after the start of cross-clamping (rs = 0.58, P < 0.001), but not with cerebral oxygen saturation. A fall of 5 per cent or more in cerebral oxygen saturation following cross-clamp application was predicted by a decrease in mean MCA blood velocity of at least 60 per cent. Changes in cerebral oxygen saturation correlated significantly with systolic blood pressure throughout the perioperative period (rs = 0.41, P < 0.001). Significant falls in cerebral oxygenation were not predicted by low stump pressure but were associated with large reductions in the mean MCA blood velocity measured by TCD.

An improved means of faecal diversion: the trephine stoma

Twenty-four patients in whom trephine stoma formation was performed over a 4-year period are described. This procedure permits the formation of an end ileostomy or colostomy without laparotomy. It is simple, rapid, safe and allows speedy recovery. It is widely applicable and previous abdominal surgery is no contraindication. The procedure was impossible in two patients who required laparotomy and in a third in whom a loop colostomy was created. Operation time was shorter and postoperative opiate requirements less than when laparotomy was undertaken for stoma formation. Follow-up (median 1 year) of 17 patients confirmed a low incidence of complications (two prolapses, one parastomal hernia) after trephine stoma formation. This procedure is recommended as the preferred method of ileostomy or colostomy formation when laparotomy is not otherwise indicated.

Endothelial cell seeding: a review

The concept of endothelial cell seeding, designed to provide vascular grafts with a nonthrombogenic lining, has progressed from crude animal experiments during the past two decades to detailed in vitro functional studies using human cells. Although favorable results have been obtained in animal studies this has yet to be translated to humans, where current application of these techniques has been limited to a very few clinical trials. The history, current status and future directions are reviewed herein.

Fibronectin binding to gelatin-impregnated Dacron (Gelseal) prostheses

Endothelial cell adherence to uncoated gelatin-impregnated Dacron (Gelseal) is poor but can be significantly improved by precoating with a suitable basement membrane such as fibronectin. To assess the suitability of fibronectin-coated Gelseal for endothelial cell seeding, fibronectin binding to Gelseal and its dissociation kinetics were investigated. Fibronectin binding was quantified by radiolabeling human fibronectin with iodine 125, concentrations of 10, 25, 50, 150, and 250 micrograms/ml being used to coat Gelseal at 30, 60, and 90 min of incubation. The amount of fibronectin bound was directly proportional to the concentration used and increased with time of incubation (p < 0.05). However, the percentage attachment decreased with increasing concentration (p < 0.001). The number of molecules bound per centimeter squared of graft was calculated. In the first 30 min, 75% of bound fibronectin was lost after exposure to a flow rate of 200 ml/min in a pulsatile artificial circulation; thereafter, the fibronectin-Gelseal bond was stable for up to 2 h.

Purification and kinetics of extracellular phospholipase A of Salmonella newport

Attempts were made to purify and study the kinetics of extracellular phospholipase A of Salmonella newport (6,8, eb; 1,2). The enzyme was purified by salt precipitation followed by gel filtration, using different grades of Sephadex. The enzymically active purified preparation was found to be a protein, having molar mass ranging between 43 and 67 kDa. The enzyme had a pH optimum at 7.5, giving 18.2 micrograms of lysophosphatidylcholine per mg protein. Its activity was enhanced by all metal ions except potassium, by solvents and surfactants except sodium dodecyl sulfate. It hydrolyzed the membrane phospholipids of red blood cells and was inhibitory to the growth of other microorganisms.

The response of rapidly formed adult human endothelial-cell monolayers to shear stress of flow: a comparison of fibronectin-coated Teflon and gelatin-impregnated Dacron grafts

Endothelial cells labeled with indium 111-oxine were seeded in supraconfluent densities onto fibronectin-coated expanded polytetrafluoroethylene (ePTFE) and gelatin-impregnated Dacron graft segments. These grafts with rapidly formed endothelial-cell monolayers were then exposed to varying shear stresses at flow rates of 200 and 300 ml/min, using tissue culture medium in an artificial flow circuit. As the loss of radioactivity represented endothelial-cell loss, cell retention was calculated by the ratio of counts recorded at different time points during 2 hours of flow to initial counts. Although initial cell adherence to gelatin-impregnated Dacron graft segments was poor compared to ePTFE, once cells were attached they resisted shear stress of flow better at 200 ml/min and equally well at 300 ml/min. The cell retention on fibronectin-coated ePTFE was 55.4 +/- 12.9% at 200 ml/min and 56.5 +/- 15.2% at 300 ml/min; cell retention for gelatin-impregnated Dacron graft segments was 69.0 +/- 6.0% and 66.5 +/- 5.5%, respectively. Qualitatively scanning electron microscopy of both ePTFE and gelatin-impregnated Dacron graft segments showed patchy coverage of grafts with cells. There was preferential attachment of endothelial cells to the nodes on ePTFE, although on gelatin-impregnated Dacron graft segments, cells conformed to the Dacron fibers at different levels and directions with evidence of bridging in the gaps between individual fibers. This study shows conclusively that rapidly formed endothelial-cell monolayers on ePTFE and gelatin-impregnated Dacron graft segments resisted a shear stress of flow equal to that seen in a femoropopliteal vein graft with significant cell retention at 2 hours.