Corneal Outcomes Following Cataract Surgery Using Ophthalmic Viscosurgical Devices Composed of Chondroitin Sulfate-Hyaluronic Acid: A Systematic Review and Meta-Analysis

Background

Ophthalmic viscosurgical devices (OVDs) are commonly used during cataract surgery to protect the corneal endothelium. A systematic literature review and meta-analysis were conducted to assess the clinical evidence of OVDs composed of chondroitin sulfate-hyaluronic acid (CS-HA) versus other OVDs in maintaining endothelial cell density (ECD) and corneal thickness (CT).

Methods

MEDLINE and EMBASE databases were searched from 2000 to 2020. Randomized controlled trials (RCTs, N ≥ 20 per group) comparing an OVD containing CS-HA (ie, VISCOAT^®, DuoVisc^® or DisCoVisc^®) to any other OVD were included. The identified comparators were limited to the OVDs found in the literature, which included those composed of HA-only or hydroxypropyl methylcellulose (HPMC). Outcomes of focus included changes in ECD (baseline to 3 months) and CT (baseline to 24 hours). Meta-analyses were performed using R software, to assess mean differences (MD) in ECD and CT change between CS-HA OVDs and HA-only or HPMC OVDs.

Results

A total of 966 abstracts were screened, and data were extracted from 12 RCTs. Meta-analyses using a random-effects model revealed significantly lower percent (%) decrease in ECD for CS-HA OVDs compared to both HA-only (MD: -4.10%; 95% CI: -5.81 to -2.40; p < 0.0001; 9 studies) and HPMC (MD: -6.47%; 95% CI: -10.41 to -2.52; p = 0.001; 2 studies) products. Similarly, % CT increase was significantly lower with CS-HA than with HA-only OVDs (MD: -3.22%; 95% CI: -6.24% to -0.20%; p = 0.04; 4 studies). However, there were no significant differences when comparing % CT change between CS-HA and HPMC OVDs (MD: 2.65%; 95% CI: -0.43% to 0.95%; p = 0.4; 2 studies).

Conclusion

CS-HA OVDs lead to less postoperative loss of endothelial cells and may better protect corneal endothelium during cataract surgery, relative to other OVDs. Future randomized studies may be needed to solidify these findings.

Impact of a Swept Source-Optical Coherence Tomography Device on Efficiency in Cataract Evaluation and Surgery: A Time-and-Motion Study

Purpose

This study aims to assess the time impact of ARGOS^® (image-guided swept-source optical coherence tomography biometer integrated with operating room (OR) technologies (SS-OCT w/ORT)) compared to LENSTAR LS 900 (optical low-coherence reflectometry (OLCR)), IOLMaster 500 (partial coherence interferometry (PCI)), and IOLMaster 700 (SS-OCT) on efficiency in the cataract evaluation and surgery.

Patients and Methods

Data from 212 patients (two study sites) who underwent evaluation and/or cataract surgery were collected. The primary objective was to compare the performance of four biometers; statistical analyses were conducted to compare 1) biometer measurement times for all patients (ANOVA w/post-hoc Dunnett's test) and stratified by cataract density (ANOVA) and 2) rate of biometer acquisition failure (Chi-square test w/post-hoc Bonferroni correction). Real-world observational data collected were then used to develop a practice-based time-efficiency model to demonstrate the combined effect that adopting an SS-OCT w/ORT has on a practice's cataract workflow. Real-world data inputs included assessment of patient's eyes' cataract grade density, time taken for optical biometry, Manual A-scan (ultrasound biometer) when acquisition failed, and measurement times associated with other devices used in cataract evaluation and surgery.

Results

For 208 patients (56% non-dense, 44% dense), the SS-OCT w/ORT biometer had a 0% acquisition failure (SS-OCT: 3% (p = 0.05); OLCR: 5% (p = 0.004); PCI: 15% (p < 0.0001)) and an average time savings of 30 seconds/patient compared to the other biometers in this study (p < 0.05). When acquisition failed, ultrasound biometry resulted in an additional 2.5 minutes/patient. For a cohort of 1000 patients, an SS-OCT w/ORT and an image-guidance system adopted at a practice using an SS-OCT, femtosecond laser, and intraoperative aberrometer offer up to 58% efficiency gain across the cataract workflow.

Conclusion

Results from this study demonstrate an SS-OCT w/ORT's efficiencies in cataract evaluation and surgery driven by faster measurement times, reducing the need for ultrasound biometry, and its integration benefits with other devices.

Comprehensive Custom-Pak® in Cataract and Vitreoretinal Surgery in Canadian Hospitals: Time and Budget Impact Analysis

Purpose

Surgical procedure packs are commonly used in ophthalmological surgeries, but quantitative evidence demonstrating the time efficiency and economic impact of their use is limited. Evaluating the time and cost of surgical pack use is particularly important for publicly funded healthcare systems with tight budgets and/or an emphasis on value-based care. This study sought to estimate the economic impact of comprehensive surgical pack use in cataract and vitreoretinal (retina) surgeries across operating room (OR), materials management, and accounting departments in Canada.

Methods

A budget impact model developed for the United States (US) from a self-reported cross-sectional study was adapted for Canada. The US study obtained data via an online survey and timing exercises of surgical procedures. The model was adapted using relevant Canadian-specific labor and cost inputs. Use of generic commodity packs (no proprietary equipment-specific supplies) was compared to full utilization of Custom-Pak^®, a comprehensive pack (disposables plus equipment-specific supplies) in cataract and retina surgeries at the facility and aggregate group (provincewide) levels.

Results

Switching from generic to comprehensive pack use in all 2500 cataract procedures at a community hospital saves 287 labor hours per year, primarily in the materials management department. Surgery preparation (OR) hours saved allow for an additional 196 potential procedures annually. Most of the Canadian Dollar (CAD) $39,815 annual cost savings are realized for the OR. Aggregating across 50,000 cataract surgeries at the provincial level yields savings of 5608 hours and 3916 additional procedures, translating to hidden cost reductions of CAD$790,632 annually. Implementing full Custom-Pak use at the facility level in 1000 retina cases saves $10,650 annually; provincewide, 127 potential additional procedures can be gained.

Conclusion

Comprehensive Custom-Pak use improves efficiency in cataract and retina surgeries saving substantial time and cost in Canadian hospitals, potentially allowing more patients to have these procedures, and reducing wait times.

Obesity Progression Between Young Adulthood and Midlife and Incident Arthritis: A Retrospective Cohort Study of US Adults

OBJECTIVE

To examine the association between weight change from young adulthood to midlife and the risk of incident arthritis.

METHODS

Using data from the National Health and Nutrition Examination Survey, we categorized participants into weight-change categories based on their recalled weight during young adulthood and midlife. We estimated the association of weight change and developing an arthritis condition over 10 years using adjusted Cox models. Findings were extrapolated to the US population to determine the proportion of incident arthritis cases that could be averted if the entire population maintained a normal body mass index (BMI) in young adulthood and midlife.

RESULTS

Among our sample of adults who were ages 40-69 years at their midlife weight measure (n = 13,669), 3,603 developed an arthritis condition. Compared with adults who maintained a normal-normal BMI, the normal-overweight, normal-obese, overweight-obese, and obese-obese groups had a significantly elevated risk of incident arthritis conditions. The obese-overweight group had a lower risk of incident arthritis conditions compared with the obese-obese group and a comparable risk to the overweight-overweight group. Nearly one-fourth of incident arthritis cases, corresponding to 2.7 million individuals, would have been averted under the hypothetical scenario where all individuals maintained normal weight from young adulthood to midlife.

CONCLUSION

Weight loss from young adulthood to midlife was associated with a substantially reduced risk of developing an arthritis condition. We found no evidence of residual risk from having been heavier earlier in life. Our findings highlight the critical need to expand obesity treatment and prevention to achieve meaningful reductions in the burden of arthritis.

Association of Weight Loss Between Early Adulthood and Midlife With All-Cause Mortality Risk in the US

IMPORTANCE

Describing potential mortality risk reduction associated with weight loss between early adulthood and midlife is important for informing primary and secondary prevention efforts for obesity.

OBJECTIVE

To examine the risk of all-cause mortality among adults who lost weight between early adulthood and midlife compared with adults who were persistently obese over the same period.

DESIGN, SETTING, AND PARTICIPANTS

Combined repeated cross-sectional analysis was conducted using data from the National Health and Nutrition Examination Survey III (1988-1994) and continuous waves collected in 2-year cycles between 1999 and 2014. The data analysis was conducted from February 10, 2019, to April 20, 2020. Individuals aged 40 to 74 years at the time of survey (baseline) were included in the analyses (n = 24 205).

EXPOSURES

Weight history was assessed by self-reported weight at age 25 years, at 10 years before baseline (midlife: mean age, 44 years; interquartile range, 37-55), and measured weight at baseline. Body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) at each time was categorized as normal (18.5-24.9), overweight (25.0-29.9), and obese (≥30.0). Weight change patterns were assessed from age 25 years (early adulthood) to 10 years before baseline (midlife).

MAIN OUTCOMES AND MEASURES

Incident all-cause mortality using linked data from the National Death Index.

RESULTS

Of the 24 205 participants, 11 617 were women (49.0%) and 11 567 were non-Hispanic White (76.9%). The mean (SD) BMI was 29.0 (6.1) at baseline. During a mean (SD) follow-up of 10.7 (7.2) years, 5846 deaths occurred. Weight loss from obese to overweight was associated with a 54% (hazard ratio, 0.46; 95% CI, 0.27-0.77) reduction in mortality risk compared with individuals with stable obesity between early adulthood and midlife. An estimated 3.2% (95% CI, 1.6%-4.9%) of early deaths could have been avoided if those who maintained an obese BMI instead lost weight to an overweight BMI by midlife. Overall, an estimated 12.4% (95% CI, 8.1%-16.5%) of early deaths may be attributable to having weight in excess of the normal BMI range at any point between early and mid-adulthood.

CONCLUSIONS AND RELEVANCE

In this study, weight loss from obesity to overweight between early adulthood through midlife appeared to be associated with a mortality risk reduction compared with persistent obesity. These findings support the importance of population-based approaches to preventing weight gain across the life course and a need for greater emphasis on treating obesity early in life.

The contribution of obesity to prescription opioid use in the United States

The prevalence of obesity has grown rapidly over the past several decades and has been accompanied by an increase in the prevalence of chronic pain and prescription opioid use. Obesity, through its association with pain, may represent an important contributor to opioid use. This cross-sectional study investigated the relationship between obesity and prescription opioid use among adults aged 35 to 79 years using data from the National Health and Nutrition Examination Survey (NHANES, 2003-2016). Relative to normal weight, body mass indices in the overweight {odds ratio (OR), 1.11 (confidence interval [CI], 0.88-1.39)}, obese I (OR, 1.26 [CI, 1.01-1.57]), obese II (OR, 1.69 [CI, 1.34-2.12]), and obese III (OR, 2.33 [CI, 1.76-3.08]) categories were associated with elevated odds of prescription opioid use. The association between excess weight and opioid use was stronger for chronic opioid use than for use with a duration of less than 90 days (P-value, <0.001). We estimated that 14% (CI, 9%-19%) of prescription opioid use at the population level was attributable to obesity, suggesting there might have been 1.5 million fewer opioid users per year under the hypothetical scenario where obese individuals were instead nonobese (CI, 0.9-2.0 million users). Back pain, joint pain, and muscle/nerve pain accounted for the largest differences in self-reported reasons for prescription opioid use across obesity status. Although interpretation is limited by the cross-sectional nature of the associations, our findings suggest that the obesity epidemic may be partially responsible for the high prevalence of prescription opioid use in the United States.

Assessment of obesity prevalence and validity of obesity diagnoses coded in claims data for selected surgical populations: A retrospective, observational study

In many types of surgery, obesity may influence patient selection, prognosis, and/or management. Quantifying the accuracy of the coding of obesity and other prognostic factors is important for the design and interpretation of studies of surgical outcomes based on administrative healthcare data. This study assessed the validity of obesity diagnoses recorded in insurance claims data in selected surgical populations.This was a retrospective, observational study. Deidentified electronic health record (EHR) and linked administrative claims data were obtained for US patients age ≥20 years who underwent a qualifying surgical procedure (bariatric surgery, total knee arthroplasty [TKA], cardiac ablation, or hernia repair) in 2014Q1-2017Q1 (first = index). Patients' body mass index (BMI) as coded in the claims data (error-prone measure) during the index procedure or 180d pre-index was compared with their measured BMI as recorded in the EHR (criterion standard) to estimate the sensitivity and positive predictive value (PPV) of obesity diagnosis codes.Among patients who underwent bariatric surgery (N = 1422), TKA (N = 8670), cardiac ablation (N = 167), or hernia repair (N = 5450), obesity was present in 98%, 63%, 52%, and 54%, respectively, based on measured BMI. PPVs of obesity diagnosis codes were high: 99.3%, 96.0%, 92.8%, and 94.1% in bariatric surgery, TKA, cardiac ablation, and hernia repair, respectively. The sensitivity of obesity diagnoses was: 99.8%, 46.2%, 41.3%, and 42.3% in bariatric surgery, TKA, cardiac ablation, and hernia repair, respectively. Among false-positive patients diagnosed as obese but with measured BMI <30, the proportion with a BMI ≥28 was 40.0%, 67.6%, 60.7%, and 65.8% for bariatric surgery, TKA, cardiac ablation, and hernia repair, respectively.Our data indicate that obesity is highly prevalent in many surgical populations, obesity diagnosis codes have high PPVs, but also obesity is generally undercoded in claims data. Quantifying the validity of diagnosis codes for obesity and other important prognostic factors is important for the design and interpretation of studies of surgical outcomes based on administrative data. Further research is needed to determine the extent to which undercoding of BMI and obesity can be addressed through the use of proxies that may be better documented in claims data.

Using Machine Learning Applied to Real-World Healthcare Data for Predictive Analytics: An Applied Example in Bariatric Surgery

OBJECTIVES

Laparoscopic metabolic surgery (MxS) can lead to remission of type 2 diabetes (T2D); however, treatment response to MxS can be heterogeneous. Here, we demonstrate an open-source predictive analytics platform that applies machine-learning techniques to a common data model; we develop and validate a predictive model of antihyperglycemic medication cessation (validated proxy for A1c control) in patients with treated T2D who underwent MxS.

METHODS

We selected patients meeting the following criteria in 2 large US healthcare claims databases (Truven Health MarketScan Commercial [CCAE]; Optum Clinformatics [Optum]): underwent MxS between January 1, 2007, to October 1, 2013 (first = index); aged ≥18 years; continuous enrollment 180 days pre-index (baseline) to 730 days postindex; baseline T2D diagnosis and treatment. The outcome was no antihyperglycemic medication treatment from 365 to 730 days after MxS. A regularized logistic regression model was trained using the following candidate predictor categories measured at baseline: demographics, conditions, medications, measurements, and procedures. A 75% to 25% split of the CCAE group was used for model training and testing; the Optum group was used for external validation.

RESULTS

13 050 (CCAE) and 3477 (Optum) patients met the study inclusion criteria. Antihyperglycemic medication cessation rates were 72.9% (CCAE) and 70.8% (Optum). The model possessed good internal discriminative accuracy (area under the curve [AUC] = 0.778 [95% CI = 0.761-0.795] in CCAE test set N = 3527) and transportability (external AUC = 0.759 [95% CI = 0.741-0.777] in Optum N = 3477).

CONCLUSION

The application of machine learning techniques to real-world healthcare data can yield useful predictive models to assist patient selection. In future practice, establishment of prerequisite technological infrastructure will be needed to implement such models for real-world decision support.

Obesity Progression Between Young Adulthood and Midlife and Incident Diabetes: A Retrospective Cohort Study of U.S. Adults

OBJECTIVE

Understanding how changes in weight over the life course shape risk for diabetes is critical for the prevention of diabetes. Using data from the National Health and Nutrition Examination Survey (NHANES), we investigated the association between self-reported weight change from young adulthood to midlife and incident diabetes.

RESEARCH DESIGN AND METHODS

We categorized individuals into four weight-change groups: those who remained nonobese (stable nonobese), those who moved from an obese BMI to a nonobese BMI (losing), those who moved from a nonobese BMI to an obese BMI (gaining), and those who remained obese (stable obese). Diabetes status was determined by self-report of a prior diagnosis, and age at diagnosis was used to establish time of diabetes onset. Hazard ratios (HRs) relating weight change to incident diabetes over 10 years of follow-up were calculated using Cox models adjusting for covariates.

RESULTS

Those who were obese and lost weight exhibited a significantly lower risk (HR 0.33; 95% CI 0.14, 0.76) of diabetes compared with those with stable obesity. We also observed lower risk among those who were stable nonobese (HR 0.22; 95% CI 0.18, 0.28) and those in the gaining category (HR 0.70; 95% CI 0.57, 0.87). Further, there was evidence of an increased incidence of diabetes among obese individuals who lost weight compared with individuals who were stable nonobese; however, weight loss was rare, and the association was not statistically significant. If those who were obese had become nonobese during the 10-year period, we estimate that 9.1% (95% CI 5.3, 12.8) of observed diabetes cases could have been averted, and if the population had maintained a normal BMI during the period, 64.2% (95% CI 59.4, 68.3) of cases could have been averted.

CONCLUSIONS

The findings from this study underscore the importance of population-level approaches to the prevention and treatment of obesity across the life course of individuals.

Economic burden of cancer among patients with surgical resections of the lung, rectum, liver and uterus: results from a US hospital database claims analysis

OBJECTIVES

To determine hospital resource utilization, associated costs and the risk of complications during hospitalization for four types of surgical resections and to estimate the incremental burden among patients with cancer compared to those without cancer.

METHODS

Patients (≥18 years old) were identified from the Premier Research Database of US hospitals if they had any of the following types of elective surgical resections between 1/2008 and 12/2014: lung lobectomy, lower anterior resection of the rectum (LAR), liver wedge resection, or total hysterectomy. Cancer status was determined based on ICD-9-CM diagnosis codes. Operating room time (ORT), length of stay (LOS), and total hospital costs, as well as frequency of bleeding and infections during hospitalization were evaluated. The impact of cancer status on outcomes (from a hospital perspective) was evaluated using multivariable generalized estimating equation models; analyses were conducted separately for each resection type.

RESULTS

Among the identified patients who underwent surgical resection, 23 858 (87.9% with cancer) underwent lung lobectomy, 13 522 (63.8% with cancer) underwent LAR, 2916 (30.0% with cancer) underwent liver wedge resection and 225 075 (11.3% with cancer) underwent total hysterectomy. After adjusting for patient, procedural, and hospital characteristics, mean ORT, LOS, and hospital cost were statistically higher by 3.2%, 8.2%, and 9.2%, respectively for patients with cancer vs. no cancer who underwent lung lobectomy; statistically higher by 6.9%, 9.4%, and 9.6%, respectively for patients with cancer vs. no cancer who underwent LAR; statistically higher by 4.9%, 14.8%, and 15.7%, respectively for patients with cancer vs. no cancer who underwent liver wedge resection; and statistically higher by 16.0%, 27.4%, and 31.3%, respectively for patients with cancer vs. no cancer who underwent total hysterectomy. Among patients who underwent each type of resection, risks for bleeding and infection were generally higher among patients with cancer as compared to those without cancer.

CONCLUSIONS

In this analysis, we found that patients who underwent lung lobectomy, lower anterior resection of the rectum (LAR), liver wedge resection or total hysterectomy for a cancer indication have significantly increased hospital resource utilization compared to these same surgeries for benign indications.

Gap Between Evidence and Patient Access: Policy Implications for Bariatric and Metabolic Surgery in the Treatment of Obesity and its Complications

Despite consistently supportive evidence of clinical effectiveness and economic advantages compared with currently available non-surgical obesity treatments, patient access to bariatric and metabolic surgery (BMS) is impeded. To address this gap and better understand the relationship between value and access, the objectives of this study were twofold: (i) identify the multidimensional barriers to adoption of BMS created by clinical guidelines, public policies, and health technology assessments; and, most importantly, (ii) develop recommendations for stakeholders to improve patient access to BMS. Updated public policies focused on treatment and clinical guidelines that reflect the demonstrated advantages of BMS, patient education on safety and effectiveness, updated reimbursement policies, and additional data on long-term BMS effectiveness are needed to improve patient access.

Carcinoid tumor of the spleen: report of a case

Carcinoid tumors are uncommon tumors of the neuroendocrine system. They grow slowly and may remain silent for years before presenting with carcinoid syndrome. A diagnosis of asymptomatic carcinoid tumor is difficult. Wide resection of the primary tumor and metastatic lesions is the first choice of treatment. Primary carcinoid is sometimes distributed throughout the entire body, but it is rare in the spleen. We herein present a rare case of a symptomless carcinoid tumor that predominantly invaded the spleen with liver metastasis.

Accurate assessment of tissue expansion in the lower face and anterior neck by a simple measurement technique

A simple, precise method of clinical estimation for the accurate assessment of tissue expansion in the lower face and anterior neck is described using fixed anatomical reference points. The method makes it possible to select the most suitable size of tissue expander and to decide the optimal timing of operation. By recording the baseline data before expansion and repeating measurements as expansion proceeds, the discrepancy of the expectation between the surgeon and patient concerning the postoperative result can also be minimised.

Use of the scalp as a donor site for large burn wound coverage: review of 150 patients

The characteristics of rapid wound healing and multiple harvest capacity make the scalp an important donor site when dealing with large and deep burn wounds. This paper reports the results of a retrospective analysis of 150 patients treated for large burn wounds. The findings indicated that bleeding during graft skin harvest could be limited to 50 ml by intradermal injection of epinephrine (1:2,000,000), high-concentration epinephrine-soaked gauze compression (1:20,000), and temporary porcine skin coverage. Use of a scalp graft also carried a low risk of complications, with only four (2.7%) major complications including three cases (2.0%) of visible alopecia and one case (0.7%) of hair transplantation. There were no hypertrophic scars, even in the patient who had the largest number (11) of repeat harvests.

Necrotizing soft tissue infections. Surgical or conservative treatment?

BACKGROUND

Both surgeons and dermatologists are increasingly challenged with the prompt diagnosis and management of severe soft tissue infections. Although early surgical intervention appears to be for life-saving in many patients, especially those diagnosed as necrotizing fasciitis, some patients recover well with only conservative treatment. Because most of these infections have similar initial clinical presentations, there remains a need to find reliable clinical and/or laboratory parameters that can predict the prognosis and to accordingly judge the necessity and timing of operation.

METHODS

We conducted a retrospective study of case records of patients with necrotizing soft tissue infections. The clinical presentation, laboratory findings, management, and therapeutic outcome of 34 cases with necrotizing soft tissue infections were reviewed.

RESULTS

These infections were potentially life-threatening, with an overall mortality of 26.5%. Shock on admission was an extremely grave sign associated with a poor prognosis (P < 0.05). In this grave condition, most (80%) patients died regardless of the choice of treatment. Coagulation parameters, including platelet counts, prothrombin time (PT), and partial thromboplastin time (PTT), were available in 21 patients, of whom 16 had at least one abnormality at their initial presentation. In these 16 patients, those who underwent surgery had a significantly higher survival rate than those who were treated conservatively (P < 0.05). Prolonged PT was significantly associated with a higher mortality (P < 0.05). Surgery did seem to correct coagulopathies. However, in patients presenting with substantial alteration of all three coagulation parameters, there was no significant difference between medical treatment and surgical intervention in terms of mortality. In such cases, mortality was high (75%). On the other hand, the prognoses of patients who presented with normal coagulation profiles were rather good. Most of them recovered well despite the therapeutic option. Surgical treatment did not seem to increase additional benefits on chances of survival. Extent of tissue plane involvement, bacteriology, and site of infection had no significant influence on patients' survival.

CONCLUSIONS

A comprehensive, well-organized, universal approach, regardless of classification, is essential for all suspected cases of necrotizing soft tissue infections. Prompt diagnostic studies are needed, and platelet counts, PT, and PTT are readily available parameters that provide substantial information on diagnosis and treatment, thus avoiding an unwarranted loss of life or unnecessary operative sequelae. Early diagnosis and, in most cases, prompt radical surgical, intervention remain the cornerstone of successful management in these infections.

Continuous antegrade warm blood cardioplegia attenuates augmented coronary endothelium-dependent contraction after cardiac global ischemia and reperfusion

BACKGROUND

Experiments were designed to evaluate the effect of warm blood cardioplegia on endothelium-dependent contraction of the coronary endothelium after cardiac global ischemia and reperfusion.

METHOD

Dogs (n = 12 in each group) were exposed to extracorporeal circulation with the body temperature at 37 degrees C (group 1) or 28 degrees C (groups 2 and 3). The ascending aorta was crossclamped for 120 minutes while continuous infusion of warm blood cardioplegec solution (group 1) or intermittent infusion of cold (4 degrees C) crystalloid cardioplegic solution (group 2) was performed via the coronary arteries through the aortic root. Cardioplegic solution was not used in group 3 animals. The heart was then allowed to function for 60 minutes of reperfusion. Reperfused (groups 1, 2, and 3) and control (group 4) coronary arteries were then harvested for study.

RESULTS

Perfusate hypoxia caused endothelium-dependent contraction in the arteries of all four groups that could be attenuated by NG-monomethyl-L-arginine (L-NMMA) or L-NMMA plus D-arginine, but not by L-NMMA plus L-arginine or endothelin receptor A and B antagonist PD 145065. The endothelium-dependent contraction results in groups 2 and 3 (75% +/- 4% and 80% +/- 5%, respectively) were significantly greater than those in groups 1 and 4 (15% +/- 3% and 18% +/- 5%, respectively). Scanning electron microscope studies showed that platelet adhesion and aggregation, areas of microthrombi, disruption of endothelial cells, and separation of the intercellular junction could be found in coronary segments from groups 2 and 3, but not in vessels from groups 1 and 4.

CONCLUSION

These experiments suggest that global ischemia and reperfusion enhances hypoxia-mediated endothelium-dependent contraction of the coronary endothelium and damages the ultrastructure. These kinds of changes can be prevented by continuous antegrade infusion of warm blood cardioplegic solution during global ischemia.

Chronic volar dislocation of the metacarpophalangeal joint of the thumb: a case report and review of the literature

A 61-year-old man sustained a chronic volar dislocation of the metacarpophalangeal joint of the thumb. He did not present for treatment until he experienced recently progressive joint pain 2 year after injury. Arthrodesis of the metacarpophalangeal joint was performed to correct the deformity of the thumb because of its extensive tissue scarring and erosion of the articular cartilage of the metacarpal head. Six weeks of splint immobilization followed by a physiotherapy program allowed the patient to resume his daily activities with his right hand.

Intramuscular cavernous hemangioma of the masseter muscle

Intramuscular hemangioma is relatively uncommon and frequently misdiagnosed, and even rarer in the head and neck region. The masseter muscle is the most frequent site for such hemangioma in the head and neck. A retrospective chart-review of intramuscular hemangioma in Keelung Chang Gung Memorial Hospital from 1983 through 1992 revealed the incidence of masseter muscle hemangioma is approximately 8% of all intramuscular hemangioma. Because of the rarity of these tumors, their vague presentations, inaccurate preoperative diagnosis and inappropriate surgical planning are common problems. This paper described five hemangiomas involving the masseter muscle with a review of the current literature on masseter muscle hemangioma.

Facial plaque-type blue nevus and its reconstruction

Blue nevi rarely appear in a plaque form. Because of their rarity and unusual clinical appearance, these nevi may present a diagnostic problem. We described a large plaque-type blue nevus measuring about 9 x 6 cm on the right cheek of a 22-year-old man. It was characterized by several dark-blue macules and papules with intervening areas of faint blue discoloration. Excision of this unusual plaque-type blue nevus with reconstruction using tissue expander was performed successfully. A 6-year postoperative follow-up revealed satisfactory results.

Plaque-type blue nevus on the face: a variant of Ota's nevus?

We describe a plaque-type blue nevus that had been present since birth on the right cheek of a 22-year-old man. It was characterized by several dark blue macules and papules with intervening areas of faint blue discoloration. Histologic examination showed a common blue nevus and a mongolian spot-like dermal melanocytosis in the dark blue and intervening faint blue pigmentary lesions, respectively.

Buttock augmentation with silicone prosthesis--a case report

A 18-year-old male patient presented with small, flat buttock due to gluteus maximus contracture which caused psychological problem. Bilateral gluteal augmentation was achieved with tissue expanders followed by permanent silicone prosthesis replacement. A two year postoperative follow up revealed no capsular contracture of the prosthesis and no limitation of the patient's activities. The improved contour has improved the patient's outlook on his body image or confidence in his body image.

Midfoot replantation: case report

The replantation of lower extremity amputations is uncommon. Foot replantation is quite rare because of the severity of the primary injury and its rare occurrence compared with lower leg and upper extremity amputations. A successful replantation in a young woman of a foot amputation at the talo-navicular-calcaneal area is reported with a 1-year postoperative follow-up revealing adequate restoration of foot function.