Risk factors for gallstone disease in the laparoscopic era.

BACKGROUND: The risk factors for gallstone disease are well known, but they have not been updated to take the development of better ultrasound technology and the advent of laparoscopic surgery into consideration. METHODS: We compared two groups of patients who underwent ultrasound-one group (n = 100) who underwent cholecystectomy after ultrasound revealed the presence of gallstones and a control group (n = 107) in whom no gallstones were shown on ultrasound. RESULTS: Seven patients in the control group refused to participate in the study; otherwise, the groups are sequential. Age in the surgery group was 51 years (+/- 16) vs 50 (+/- 16) for the control group. The percentage of female patients was 59% and 52%, respectively (p = ns). Body mass index was 32 (+/- 8) and 28 (+/- 6), respectively (p = 0.013). Parity > 2 was 0.49% and 0.37%, respectively (p = 0.000001). The number who breast-fed at least one child was 17 (24%) and eight (12%), respectively (p = 0.03). Oral contraceptive use was 37 (52%) and 17 (22%), respectively (p = 0.0005). Primary relatives who had had gallbladder surgery was 0.68 (+/- 1) and 0.35 (+/- 0.6), respectively (p = 0.02). CONCLUSION: Body mass index, breast-feeding, oral contraceptives, parity > 2, and family history were found to be risk factors for gallstone disease. Age and female sex were not, probably due to selection bias.

Combined quality improvement ratio: a method for a more robust evaluation of changes in screening rates.

INTRODUCTION: It has been proposed that a ratio of the discordant cells from a McNemar's Chi-square table be used as a measure of quality improvement, and that this measure be called the Quality Improvement Ratio (QuIR). As proposed, patients enrolled in only one year of a two-year study are excluded from the McNemar's table of the QuIR. Since the original proposal of the McNemar's Chi-square in 1947 included application to matched pair data, a more comprehensive analysis would be possible if the single-year enrollees were matched into pairs. METHODS: Patients enrolled in only the first study year are matched and paired with patients enrolled in only the second study year. The pairs are matched on variables important to the disease or process being evaluated. The matched pairs are combined with the repeatedly measured subjects to increase the statistical power of the analysis. The Combined Quality Improvement Ratio (CQuIR) is demonstrated with parameters from the original articles, in a--Markov chain Monte-Carlo simulation, so a direct comparison can be made. RESULTS: CQuIR improved statistical power, especially in simulations of small populations. In some simulations the statistical power was double that of the QuIR alone. DISCUSSION: Although the QuIR provides important information, the CQuIR allows more of the data to be used to evaluate the effect of interventions in policy, delivery, and practice. The increase in statistical power of the CQuIR over the QuIR can facilitate successful evaluation of health care services.

A method to report utilization for quality initiatives in medical facilities.

OBJECTIVE: We undertook this project to outline a methodology for quantifying aggregate health care utilization of medical "technologies" that could be rank ordered by volume. The identification of specific high-volume technologies could guide future efforts for quality initiatives such as program planning, preventive services implementation, quality improvement activities, and innovative and cost-effective technology development. DESIGN: This study utilized a retrospective cross-sectional study design. METHODS: We generated combined ranks for the top 200 high-volume procedures from three data sources that incorporated in- and outpatient procedures. Data were collected using primarily ICD-9 and CPT-4 codes; all codes were translated into CPT-4 codes and collapsed into categories using truncated three-digit CPT-4 codes. Frequencies for each collapsed code were determined with each dataset; procedures were reranked based on the mean rank of the three sources. MAIN OUTCOME MEASURES: We itemized the individual procedure codes making up each of the top 20 categories and reported the unique codes making up at least 80% of the procedure code category. RESULTS: The top five procedure categories identified in this study were patient visits (inpatient and outpatient), chest x-rays, mammograms, ophthalmological services, and electrocardiograms. CONCLUSION: The methodology described provides a new way to combine and concisely report on utilization of procedures that is relevant to data obtained from different sources. This methodology may be of potential benefit to health care administrators, technology developers, and other planners as they contemplate ways to identify quality and technology development initiatives that can have a broad impact on populations served by health care organizations.

The role of mathematical modeling in medical research: "research without patients?".

Computer controlled mathematical models of medical outcomes are commonly found in the current medical literature. What is less common is an understanding of the methods used to construct such models, leaving the consumers of medical research to accept the interpretations as presented. A basic knowledge of the concepts used to generate models will provide the clinician with the insight needed to critically evaluate medical literature based on mathematical models.

Hemorrhagic ocular complications associated with the use of systemic thrombolytic agents.

OBJECTIVE: This study aimed to report three patients with hemorrhagic ocular and orbital complications associated with the use of systemic thrombolytic agents. DESIGN: The study design was a retrospective small case series. PARTICIPANTS: Three eyes of three patients were studied. INTERVENTION: Surgical procedures to reduce intraocular pressure or relieve optic nerve compression were performed. MAIN OUTCOME MEASURES: Visual acuity and intraocular pressure were measured. RESULTS: Three patients received an intravenous thrombolytic agent on diagnosis of an acute myocardial infarction. One patient had a spontaneous suprachoroidal hemorrhage develop with secondary acute angle closure glaucoma shortly after receiving tissue plasminogen activator. Another patient had an orbital hemorrhage develop on receiving tissue plasminogen activator 4 days after an uncomplicated cataract extraction. The third patient experienced an orbital hemorrhage while receiving streptokinase 1 day after undergoing an external levator resection. Two patients suffered significant visual loss due to glaucoma or compressive optic neuropathy. CONCLUSIONS: The onset of eye pain or visual loss after the administration of a systemic thrombolytic agent should alert the physician to the possibility of an ocular or adnexal hemorrhage. Prompt diagnosis and treatment can improve the likelihood of a favorable visual outcome.

Bungee cord-associated ocular injuries.

PURPOSE: To report ocular injuries associated with the use of bungee cords. METHOD: Four patients with bungee cord-associated ocular trauma are presented. RESULTS: Four eyes of four patients demonstrated severe contusion injuries associated with bungee cord trauma. Ocular injuries in the four eyes included a variable combination of corneal abrasion, hyphema, iridodialysis, anterior chamber angle recession, secondary glaucoma, lens subluxation, vitreous hemorrhage, and retinal detachment. Three of the four eyes required ophthalmic surgery. All eyes had anterior chamber angle recession and required continuing ophthalmic care. CONCLUSION: Bungee cords may be associated with severe ocular injury and should be used with caution.

The prognostic impact of immunosuppression and cellular rejection on cardiac allograft vasculopathy: time for a reappraisal.

BACKGROUND: Our current immunosuppressive strategies have made little impact on the development of cardiac allograft vasculopathy, the leading cause of long-term allograft loss. This study sought to evaluate the relationship of cellular rejection and immunosuppressive therapy with the development of morbid events resulting from cardiac allograft vasculopathy. METHODS: The study population consisted of 163 consecutive patients who received heart transplants between January 1990 and May 1994. Data regarding nonimmunologic risk factors (lipids, obesity indexes, hypertension, donor age and sex, cytomegalovirus infection, diabetes mellitus, time after transplantation, and cold ischemic time), immunologic factors (histocompatibility, episodes of treated rejection, and average first-year biopsy rejection score), and immunosuppressive regimens (cumulative prednisone dose, average daily prednisone dose, mean cyclosporine level, average cyclosporine daily dose, cumulative azathioprine dose, and average daily azathioprine dose) were collected and analyzed in all patients. The diagnosis of cardiac allograft vasculopathy was established in all patients by a combination of necropsy, angiography, and intravascular ultrasound examination of the allograft vasculature. Cardiac events were defined as sudden death, myocardial infarction, and need for revascularization. RESULTS: Of all variables assembled, stepwise logistic regression recognized cumulative prednisone dose > 15 gm (relative risk [RR] 5.7; p = 0.01), donor age > 35 years (RR 3.73; p < 0.05), and average biopsy rejection score > 1 (RR 2.77; p < 0.05) as independent adverse predictors of cardiac events. In distinction, average daily cyclosporine dose > 4.5 mg/kg/day was found to confer a protective effect (RR 0.16; p = 0.03). CONCLUSIONS: The development of cardiac events as a result of cardiac allograft vasculopathy is influenced by the interdependence of allograft rejection and the balance of immunosuppression. The clinical implications of these findings point to the need for a reappraisal of our traditional approach to using corticosteroids (acute and maintenance) and cyclosporine (maintenance) in heart transplantation.

Interferon alfa-associated retinopathy.

Interferon alfa and its related compounds have been used for more than 10 years in the treatment of a number of conditions including viral illnesses, childhood hemangiomas, various cancers, and leukemia. The potential applications for this class of medication continue to grow. The use of interferon alfa in experimental protocols has also increased, thus making it more likely that new indications will be discovered. It is probable that primary care physicians will be called on to initiate therapy or will see patients being treated with interferon in their practice. We report the development of interferon-related retinopathy in a 43-year-old man while he was receiving experimental treatment with interferon alfa for hepatitis B virus and hepatitis C virus infection. The vision loss was acute and only partially reversible. Interferon, its mechanism of action, and the past literature are briefly discussed.

Diabetic retinopathy during pregnancy.

This article outlines the pathophysiology of diabetic retinopathy, its epidemiology, and its diagnosis. Recommendations for management of the pregnant diabetic patient through the team approach has resulted in a dramatic improvement in maternal and fetal complications during pregnancy. By including a retinal specialist in the team during each trimester, the effects of pregnancy on the progression of diabetic retinopathy should be nearly identical to that of the non-pregnant patient.

Survivorship of healed partial foot amputations in dysvascular patients.

The results of 94 initially successful, partial foot amputations in dysvascular patients were reviewed with survivorship analysis at a minimum of 6.5 years after surgery. Partial foot amputations were divided into three types: transmetatarsal amputations, metatarsophalangeal disarticulations, and ray resections. No amputation type was more or less likely to be treated with subsequent amputation of the foot or to develop recurrent ulceration. Taking all groups together, the chance of retaining the foot after an initially healed partial foot amputation was 86% at four years after operation and 76% at eight years after operation. Of these surviving feet, however, 53.8% developed ulceration or needed local reoperation. The chance of completely avoiding any surgery after an initially healed partial foot amputation was 71% at four years after operation and 52% at eight years after operation. In properly selected patients, partial foot amputations have significant longevity.

Syme amputation in patients with severe diabetes mellitus.

Surgical results and functional outcome of 52 patients treated with Syme amputations for forefoot gangrene between 1986 and 1988 were retrospectively reviewed with reference to the predictive value of posterior tibial artery Doppler examination. Wound healing was correlated with the preoperative status of the posterior tibial artery. Functional outcome was assessed by the ability to wear a prosthesis, ambulatory capabilities, episodes of ulceration, and revision surgery. Follow-up averaged 27 months. Twenty-nine patients had a posterior tibial artery with either a triphasic waveform (N = 23) or a normal pulse (6). Twenty-six (90%) of these achieved a healed wound suitable for prosthetic wear. Twenty-three patients had monophasic flow in the posterior tibial artery. Thirteen (57%) of these achieved a healed wound. Ninety percent of the patients who achieved healed wounds were fit with a prosthesis. Functional level of ambulation was assessed in 20 patients. Eighteen were community level ambulators, 11 could walk three or more blocks, and 16 could climb stairs. Eighteen wore their prosthesis all day. These findings indicate that posterior tibial artery Doppler examination is predictive of healing in the Syme amputation performed on diabetics. Furthermore, diabetics can attain a functional level of ambulation with a Syme amputation.

False-positive magnetic resonance imaging of a metastatic carcinoma simulating a malignant melanoma.

Previous studies have shown the value of magnetic resonance imaging (MRI) in the diagnosis of malignant melanoma of the choroid. We describe the case of a patient with a choroidal mass whose MRI study was characteristic of malignant melanoma. Subsequently the eye was enucleated. However, on histopathologic examination, the mass was a metastatic carcinoma to the choroid. This false-positive study makes us question the value of MRI in the diagnosis of malignant melanoma of the choroid.

Activated retinitis pigmentosa peripheral lymphocytes adhere to and alter cultured human retinal pigment epithelial cells.

Interleukin-2 receptor (IL-2R) is an activation molecule that, when expressed on peripheral blood lymphocyte (PBL) membranes, indicates the secretion of IL-2 and initiation of an immune system activation cascade. Comparing the average of IL-2R expression in 34 patients with retinitis pigmentosa (RP) syndrome (561 +/- 282 cells/mm3; mean +/- standard deviation) with 35 age-matched normal subjects (194 +/- 39 cells/mm3), it was found that those with RP had greater numbers of IL-2R-positive cells (P less than 0.001). The increased amounts of IL-2R on PBL of 29 RP and the homotypic self-aggregation of RP PBL by phase and scanning electron microscopy led to the study of the interaction of RP PBL with cultured human postmortem retinal pigment epithelial cells (RPE). A direct correlation was found between the amount of IL-2R expression and the numbers of RP lymphocytes adhering to RPE monolayers. However, the adherence effect was not unique to RP syndrome but appeared to be a nonspecific result of lymphocyte activation. Greater adherence to RPE than normal also was observed in PBL from disease control subjects with elevated IL-2R values and in PBL stimulated by the mitogen, concanavalin A (Con-A). In addition, RPE monolayers were destroyed by Con-A-stimulated PBL that showed 95-98% IL-2R expression. Similar, but less serious effects, occurring in RPE cells after 1 wk's cocultivation with RP PBL, suggested that activated RP lymphocytes can be cytotoxic to RPE during prolonged contact. Because macrophage-like cells and class II major histocompatibility complex expression have been found in RP-affected retinas, immune-mediated cytopathologic effects may contribute to retinal degeneration in RP.

Systemic immunostimulation after retinal laser treatment in retinitis pigmentosa.

Systemic immunostimulation followed an experimental treatment trial of scatter argon laser photocoagulation directed to the retina of one eye of 10 patients with heredo-degenerative retinitis pigmentosa (RP). Significantly increased RP lymphocyte CD25, CD26, and CD4/CD26 activation epitope expressions over prelaser values and controls were found with a normalization of soluble interleukin-2 receptor secretion after laser treatment. Serum interferon-gamma was low both pre- and postlaser. Interestingly, when a panel of viral antibodies was tested, only those to rubella virus were elevated in the early postlaser period. The character of RP immunostimulation after laser-induced inflammation could be consistent with an antigenic stimulus from laser-released retinal proteins which might be of autoimmune or latent infectious origin. Enhanced immune responses may be a common but unrecognized sequellae of retinal laser.

Modified vitrectomy for impending macular holes.

We report a consecutive series of 13 eyes (11 patients) treated with pars plana vitrectomy, in which surgical manipulation of the prefoveal layer of cortical vitreous was avoided, for stage I (eight eyes) and stage II (five eyes) macular hole formation. Average follow up was 8.1 months (range, 2 to 13 months). There was no significant improvement in vision in the patients with stage II macular holes; however, vision in these patients stabilized and did not fall below 20/400. Visual acuity improved in seven of the eight patients with stage I holes. The results for both these groups achieved by our modified vitrectomy, which is relatively easy to perform and involves minimal intraoperative manipulation of the fovea, are consistent with those obtained by methods involving more aggressive cortical vitreous stripping of the fovea.

Scanning electron microscopic study of microaneurysms in the diabetic retina.

We describe the clinical and pathologic appearance of the retinal microcirculation in a patient with a 22-year history of diabetes mellitus. A vascular cast of one eye was prepared and studied with scanning electron microscopy. The three-dimensional views obtained give insight into the pathogenesis of microaneurysms.

Pathogenesis of retinal dystrophy in the Royal College of Surgeons rat.

The Royal College of Surgeons (RCS) rat is an animal with genetically transmitted progressive retinal dystrophy. We compared histopathologically the RCS rat retina with normal age-matched control retinas (Long-Evans rats) using light and scanning electron microscopy. Retinal degeneration begins with alteration of the rod outer segments. There is a progressive involvement of the entire retina, with all layers affected by 45 days. The three-dimensional view obtained with scanning electron microscopy provides another perspective on the pathogenetic changes of the RCS retina.

The viscous fluid pump.

We describe a device useful for injection of viscoelastic material into the vitreous cavity for internal tamponade. The instrument has proven to be reliable and "user friendly" in a clinical setting.