Acute choke zone effects: Lessons from radioactive and fluorescent microspheres in a pig model muscle flap.

BACKGROUND: Choke vessels dilate and contract to regulate blood flow between adjacent arterial angiosomes. In skin flap surgery, when arterial inflow to an angiosome is ligated, choke vessels allow blood supply from an adjacent angiosome. In muscle flap surgery, the vascular anatomy is analogous to skin flaps; however, while it is established that the choke vessels will fully dilate irreversibly after two to three days, no study has yet analyzed the acute changes in each vascular region immediately following ligation of one pedicle. OBJECTIVE: To establish whether the choke vessels open or close immediately following ligation of a pedicle, and how this change affects blood flow in the adjacent proximal and distal vascular regions. METHODS: Radioactive and fluorescent microspheres in a pig model were used to study the regional intramuscular blood flow in each anatomical zone of a rectus abdominis flap. Blood flow measurements for each zone were calculated relative to the entire muscle at preligation, ligation and various times (15 min to 90 min) postligation. RESULTS: There was no statistically significant difference in blood flow across choke zones as a result of ligation. This signifies that the choke vessels do not significantly dilate to produce a statistically significant measureable change in blood flow. CONCLUSIONS: Given these results and previous literature findings, the anatomical presence of choke vessels in a muscle is the strongest determining factor for acute flap viability in surgery.

HISTORIQUE: Les vaisseaux anastomotiques se dilatent et se contractent pour réguler le débit sanguin entre les angiosomes artériels adjacents. Dans le cadre d'une chirurgie par lambeau cutané, lors de la ligature du débit artériel vers un angiosome, les vaisseaux anastomotiques assurent un débit sanguin en provenance d'un angiosome adjacent. L'anatomie vasculaire est alors analogue aux lambeaux cutanés. Cependant, bien qu'il soit établi que les vaisseaux anastomotiques se dilatent pleinement et de manière irréversible au bout de deux ou trois jours, aucune étude n'a encore analysé les changements aigus de chaque région vasculaire immédiatement après la ligature d'un pédicule. OBJECTIF: Établir si les vaisseaux anastomotiques s'ouvrent ou se ferment immédiatement après la ligature d'un pédicule et examiner l'effet de ce changement sur le débit sanguin des régions proximales et distales adjacentes. MÉTHODOLOGIE: Les chercheurs ont utilisé les microsphères radioactives et fluorescentes d'un porc pour étudier le débit sanguin intramusculaire régional de chaque zone anatomique d'un lambeau du grand droit. Ils ont mesuré le débit sanguin de chaque zone par rapport au muscle entier avant la ligature, au moment de la ligature et à divers moments (de 15 à 90 minutes) après la ligature. RÉSULTATS: Il n'y avait pas de différence statistiquement significative du débit sanguin dans les diverses zones anastomotiques après une ligature. Ainsi, les vaisseaux anastomotiques ne se dilatent pas au point de produire un changement du débit sanguin pouvant être mesuré de manière statistiquement significative. CONCLUSIONS: Compte tenu de ces résultats et des conclusions de publications scientifiques, la présence anatomique de vaisseaux anastomotiques dans un muscle est le principal déterminant de viabilité aiguë d'un lambeau lors d'une chirurgie.

Asphyxial games or "the choking game": a potentially fatal risk behaviour.

OBJECTIVES: To determine the prevalence of knowledge about and participation in asphyxial games, sometimes called "the choking game", and how best to raise awareness of this risk-taking behaviour and provide preventive education. DESIGN: Questionnaire; collaborative research model; lay advocacy group/university researchers. SETTING: 8 middle and high schools in Texas (six) and Ontario (two). A recent death from playing the choking game had occurred in one Texas school, and two other fatalities had occurred within the state. SUBJECTS: Students in grades 4-12, aged 9-18 years. INTERVENTION: None. OUTCOME MEASURES: None. RESULTS: Of 2762 surveys distributed, 2504 (90.7%) were completed. The mean (SD) age of the responders was 13.7 (2.2) years. 68% of children had heard about the game, 45% knew somebody who played it, and 6.6% had tried it, 93.9% of those with someone else. Forty percent of children perceived no risk. Information that playing the game could result in death or brain damage was reported as most likely to influence behaviour. The most respected source of a preventive education message was parents for pre-adolescents (43%) or victim/victim's family (36%) for older adolescents. CONCLUSIONS: Knowledge of and participation in self-asphyxial behaviour is not unusual among schoolchildren. The age of the child probably determines the best source (parents or victim/victim's family) of preventive education.

Pediatric hand fractures: a review.

OBJECTIVE: To identify the incidence, causes, and details of hand fractures in children. DESIGN: A retrospective chart review. METHODS: Records of children under 16 years of age who had sustained a hand fracture within the last 5 years were collected from the patient population of British Columbia's Children's Hospital. A total of 242 hand fractures in 232 patients were documented. These patients were reviewed for age at time of injury, gender, location of the incident, mechanism of injury, number of radiographs taken, and fracture specifics. Radiographs with obscure details or incomplete folders were excluded. RESULTS: The patients consisted of 57 (24.6%) females and 175 (75.4%) males, with a mean age of 11.1 +/- 3.3 years. Incidence was low in early childhood but rose sharply after age 9 and peaked at 12 years of age. Sporting activities were the most common cause in both sexes. The fifth metacarpal was the most frequently involved bone (21.1% of total). Nonepiphyseal fractures accounted for 60.2% of the fractures, and the remaining 39.8% were epiphyseal fractures, predominantly Salter-Harris type II (90.4%). Fractures with comminution, severe displacement, intraarticular involvement, and condylar involvement were seen in 12.4%, 12.4%, 20.5%, and 15.1%, respectively. An average of 4.2 radiographs were taken per patient. CONCLUSION: Almost all fractures healed in 2 to 3 weeks with excellent functional outcome. Knowledge of epidemiology and etiology of hand fractures can serve as an essential first step in devising strategies to reduce the incidence of these hand injuries. It is hoped that studies such as the present study may serve as a first step in planning measures to reduce the occurrence of hand fractures.

The structure and correlates of kanashibari.

The present research is an examination of the parameters and correlates of kanashibari, operationally defined as being unable to move upon awakening or before falling asleep. Nonclinical Japanese individuals (N = 720), 34% of whom reported an experience of kanashibari at least once, were administered D. I. Templer's (1970) Death Anxiety Scale, R. Brown's (1990) Locus of Control Scale, and a questionnaire devised by the authors to collect information about kanashibari. The results showed that the kanashibari experience was positively correlated with death anxiety, with being a woman, and with external-other locus of control; this last measure assessed the extent to which these individuals felt that their lives were determined by fate, good luck, or chance.

Development of a three-scale MMPI: the MMPI-TRI.

A 60-item short form of the MMPI with very high content validity and items that appear on both the MMPI and MMPI-2 was developed and named the MMPI-TRI. It contains three 20-item scales--the Subjective Distress, Acting-Out, and Psychosis scales. These three scales have excellent internal consistency and sufficient independence from each other. An anxiety and depression group of patients, prison inmate group, and a schizophrenic and other psychotic group had the highest mean scores on Subjective Distress, Acting-Out, and Psychosis, respectively. Correlations with the 13 regular scales of the MMPI and MMPI-2, their content and supplementary scales, and four other psychometric instruments provided very strong evidence for validity. Norms are provided.

Borderline, depressive, and schizophrenic discrimination by MMPI.

This study intended to differentiate among borderline personality disorder (BPD), schizophrenic, and depressed patients on the basis of their MMPI profiles. MMPI profiles of 237 psychiatric inpatients were selected on the basis of their primary DSM-III admission diagnoses. Analysis of MMPI mean scores and discriminant function analysis supports previous literature in describing borderline patients as having a broad spectrum of psychopathology typified by an attitude of alienation and rebelliousness, atypical thought content and/or process, and eccentric behavior. Schizophrenic patients are differentiated from BPD patients by the presence of thought disorder and psychotic-like manifestations. The depressed patients did not show the aforementioned extreme characteristics of the other two groups.

Variables associated with success in an adolescent drug treatment program.

The purpose of this study was to investigate the variables that predicted success in an adolescent inpatient drug treatment program. The prognosis in 94 adolescent polydrug abusers was determined on the basis of the MMPI, the Millon Adolescent Personality Inventory, Wechsler IQ, and historical variables. Favorable outcome was associated with being female, having fewer legal difficulties, fewer neurological risk factors, less pathological MMPI scores, higher Verbal IQ, and lower Performance IQ.

Neuropsychological deficits in active licensed professional boxers.

Young, active, licensed professional boxers (N = 19) were found to display a pattern of neuropsychological deficits consistent with the more severe punch-drunk syndrome of years past. These deficits resulted in significantly lower test performance than that of control athletes (N = 10) matched for race, age, and level of education. Tests that showed significant differences between groups include subtests of the Quick Neurological Screening Test, subtests of the Halstead-Reitan Neuropsychological Test Battery, and the Randt Memory Test. Fifteen of the 19 boxers scored in the impaired range of the Reitan Impairment Index, as compared to 2 of the 10 controls.