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.

Robin sequence: clearing nosologic confusion.

OBJECTIVE: To gather evidence surrounding the confusion in the classification of Robin sequence and inform those who have the power to make the changes in defining this symptom complex. METHOD: A questionnaire was sent to all participating cleft palate teams (N=204) of the American Cleft Palate-Craniofacial Association. The questionnaire identified the precise, different characteristics for diagnosing Robin sequence and evaluated whether the difference between a retrognathia and micrognathia influenced the diagnosis process. We subsequently also investigated whether the cleft type (i.e., U-shaped versus V-shaped) had any influence in the decision-making process. A PubMed literature review of the 50 most recent manuscripts about Robin sequence was evaluated also. RESULTS: Seventy-three questionnaires were received. This 35% response rate revealed 14 different definitions of Robin sequence. A PubMed literature review of 50 consecutive manuscripts revealed 15 different descriptions. CONCLUSION: This study confirms that nosologic confusion is widespread with regard to defining Robin sequence. This has implications for evaluating Robin sequence, giving advice about the prognosis and genetic counseling, and refining treatment options.

Vascular resistance in human muscle flaps.

Important differences in free muscle flap survival have been reported in the setting of long arterial and venous vein grafts. The authors provide insight into the etiology of flap failure by addressing the following question: Do differences in flap type result in clinically significant different vascular resistances and consequently anastomotic patency? A total of 15 human flaps were studied intraoperatively: 9 gracilis, 3 rectus abdominis, and 3 latissimus dorsi. The muscle was isolated on a single pedicle and hemodynamic stability was ensured. The venous pedicle was then divided. A timed collection of effluent was used to determine flow. Vascular resistance was calculated by dividing the change in pressure by the flow, and standardizing this for temperature and hematocrit. Average vascular resistance and standard deviation for the gracilis, rectus, and latissimus flaps was 10.34 +/- 7.77 mmHg per milliliter per minute, 2.79 +/- 1.50 mmHg per milliliter per minute, and 3.17 +/- 1.05 mmHg per milliliter per minute respectively. An inverse relationship between muscle vascular resistance and flap mass was found (p < 0.001). This indicates that larger muscles have less vascular resistance. The decreased resistance gives rise to higher flow rates and, as a result, potentially improved vein graft patency. The clinical implication is that a larger flap should be used when high flow-through is critical. The role of flap vascular territory makeup continues to be pursued.

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.

Lipoma of the cleft soft palate: a case report of a rare congenital anomaly.

OBJECTIVE: Congenital tumors of the oral cavity are extremely uncommon. The teratoid tumors (epiganthi, dermoid, and hairy polyps) account for almost all of the reported cases and are not infrequently associated with cleft of the soft palate. Of the remaining tumors in the pediatric cleft palate population, infantile lipoma of the oral cavity is exceedingly rare. A case of a congenital lipoma associated with a cleft of the soft palate is presented. The review of the literature, the description of the lesion, the diagnosis, and the management of this finding are outlined.

Lower extremity burns and Unna paste: can we decrease health care costs without compromising patient care?

OBJECTIVE: To compare an alternative treatment for lower extremity burns with the standard in-hospital treatment, in an attempt to shorten hospital stay. DESIGN: A case-control series. SETTING: A university-affiliated hospital. PATIENTS: All patients with a burn isolated to a lower extremity were treated over an 8-month period with split-thickness skin grafting (STSG), Unna paste dressing, immediate mobilization and early discharge. This group was compared with matched controls from the preceding 8 years treated with STSG, occlusive burn gauze dressing, bed rest and hospitalization. MAIN OUTCOME MEASURES: Duration of hospital stay and graft viability. RESULTS: Thirteen patients with an average wound size of 131 cm2 were treated with Unna paste and had a graft viability of greater than 95% and a burn-scar rating equivalent to that of patients treated with the earlier regimen. The duration of hospital stay decreased from a mean of 12.9 days to 1.4 days, with no complications. This translated into a saving of $10,350 per patient. CONCLUSIONS: This alternative treatment is safe, inexpensive and effective and is recommended as the treatment of choice for uncomplicated, noncircumferential lower extremity burns.

Osseointegration in sinus-forming bone.

Osseointegration, using bone-anchored titanium fixtures, is a well-established technique for both intraoral and craniofacial prosthetic rehabilitation. The use of this technique in children can be complicated by craniofacial growth and sinus development. This study evaluates the effects of sinus formation and growth on the fate of osseointegrated titanium fixtures in the growing porcine model. At 3 weeks of age, six Landrace White cross male pigs had a 3.75 x 3.0 mm titanium fixture (Noblepharma) inserted into their right frontal bone where the right frontal sinus would subsequently develop. Preoperative CT scans with three-dimensional reconstructions were used to determine the insertion site. To follow the effects of growth and sinus formation, CT scans with three-dimensional reconstructions and cephalometric radiographs were taken at 1, 3, 6, and 9 weeks postoperatively and at sacrifice. The pigs were sacrificed serially, and direct osteometric measurements were taken to determine skull symmetry. All skulls were sectioned, and osseointegration was determined clinically, radiologically, and histologically with light and scanning electron microscopy. Five of the six fixtures osseointegrated. There were no apparent growth disturbances due to the fixtures. As growth progressed, the osseointegrated fixtures submerged into the frontal bone in a posteroinferior direction to become completely intraosseous 14 weeks after insertion. As the frontal sinus pneumatized, the fixtures remained osseointegrated, but progressive amounts of the fixtures became exposed in the sinus. From this study it would appear that osseointegrated titanium fixtures do not have any effect on calvarial growth and gradually submerge into the growing bone. As sinus development ensues, the fixtures remain integrated but become partially exposed within the sinus.(ABSTRACT TRUNCATED AT 250 WORDS)

Revascularization of a seven-week-old infant lower extremity: case report.

A seven-week-old infant suffered a closed segmental fracture of the left tibia and fibula complicated by vascular disruption and a secondary compartment syndrome. Initial orthopedic assessment revealed a clinically mottled, cool, pulseless extremity 4 hr post-injury. Radiologic investigations showed multiple displaced fractures of both the tibia and fibula. The infant underwent four compartment fasciotomies and intramedullary nailing of the tibial fractures. The vascularity of the limb failed to improve significantly. Angiograms done 22 hr post-injury revealed disruption of arterial inflow just distal to the bifurcation of the tibial peroneal trunk and posterior tibial artery. Urgent revascularization utilizing a contralateral greater saphenous vein graft was undertaken with a successful outcome. Despite delay in transport from the community hospital and lack of definitive management of the vascular injury, the infant has had a good-to-excellent functional outcome.

Experimental calvarial growth disturbance by micro-plate and screw fixation.

A study was designed to help ascertain the effects of rigid internal fixation in the growing skull. Five piglets underwent plating of the left coronal suture at 3 weeks of age. At the time of surgery metal markers were placed to follow bone growth. Cephalometric radiographs, direct osteometry at sacrifice, gross pathological examination and specimen radiography revealed a localized disturbance of growth. There was a restriction of sutural displacement and appositional bone growth at the site of the plate. Local restriction of sutural growth was almost complete during the experimental period. There was an alteration to a 'mature' suture morphology, without synostosis, of the suture on the plated side not seen on the control side. A plagiocephalic pig was not produced nor was there an orbital deformity. A large local contour deformity developed and by the end of the experimental period the plate had become completely incorporated in bone. These effects were statistically significant as well as clinically significant. The clinical use of this type of fixation in reconstructive surgery of the infant craniofacial skeleton is questioned in light of the result.

Detection of micrometastases from primary breast cancer.

The monoclonal antibody LICR-LON-M8 was used in a series of experiments to determine how an immunohistochemical technique could be used as a diagnostic test for micrometastatic disease in patients with operable, primary breast carcinoma. Optimal tissue and antigen preservation was obtained with fixatives containing either picric acid or a heavy metal such as mercury to allow staining with the monoclonal antibody diluted to 1:12,000 to 1:16,000 from unpurified mouse ascites. Tissue affected by primary and metastatic disease stains in a characteristic fashion, which is distinct from benign breast tissue. All the ductal tumours stained positively for malignant cells with the monoclonal antibody preparation. Within the bone marrow, occasional granulocytes and granulocyte precursors stained positively if the endogenous peroxidase activity was incompletely blocked. These cells were readily differentiated from tumour cells on cytologic examination. With these monoclonal antibody and immunohistochemical staining techniques it may now be possible to detect early micrometastatic disease in the bone marrow of patients with primary breast cancer.

Monoclonal antibody LICR-LON-M8 does not predict the outcome of operable breast cancer.

The prognostic value of the monoclonal antibody LICR-LON-M8, which has been shown to detect micrometastatic disease, was evaluated in a prospective, double-blind, clinical study of bone-marrow specimens from patients with operable breast cancer. Four bone-marrow specimens, obtained from each of 50 patients at the time of excision of the primary breast tumour, were examined immunohistochemically, with LICR-LON-M8 as the primary antibody. All of the primary tumour specimens demonstrated positive staining for malignant disease with LICR-LON-M8. The bone-marrow specimens of four patients demonstrated positive staining: three specimens were "suspicious" for malignant cells and one contained definite malignant cells on cytologic examination. This gave a 2% rate of detectable micrometastatic disease at the time the primary tumour was excised. Patient follow-up averaged 21.5 +/- 9.1 months. The test results did not correlate with outcome. A negative test result with LICR-LON-M8 did not imply a better prognosis. The authors conclude that examination of bone-marrow specimens stained with LICR-LON-M8 in patients with operable breast cancer is of no clinical value. Furthermore, the low rate of micrometastases detected is at variance with that reported by others. In view of the natural history of breast cancer, the authors believe that their results were not unexpected and they question the importance of other results.

Rating the burn scar.

A reliable, objective, and universal method of assessing burn scars does not exist in today's burn literature. Such a method is necessary to provide a descriptive terminology for the comparison of burn scars and the results of treatment. The method should be applicable to patients both within an institution and between burn centers. A burn scar assessment has been devised based on physical parameters. These relate to the healing and maturation of wounds, cosmetic appearance, and the function of the healed skin. Pigmentation, vascularity, pliability, and scar height are assessed independently, with increasing score being assigned to the greater pathologic condition. Normal skin has a score of 0. Seventy-three patients were assessed by three separate occupational therapists and the findings subjected to statistical analysis for interrater reliability. For each parameter a Cohen's kappa statistic of approximately 0.5 +/- 0.1 indicates a statistically significant agreement between observers. These values were found to improve with time. This appears to be a useful tool for the assessment of burn scars, allowing objective comparison of the same scar by different observers.

Recognition and treatment of the post-traumatic stress disorder in the burn victim.

In 1980 the third edition of the Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association (DSM-III) provided the first descriptive classification for post-traumatic stress disorder as a unique diagnostic entity. Since then, many reports describing this condition in Vietnam War veterans have appeared, as well as occasional reports of the disorder after civilian trauma. We have found only one previous report of this disorder as a sequela to thermal injury. This article presents two illustrative case reports of burn victims suffering from post-traumatic stress disorder, highlighting the phenomenology leading to the diagnosis. The treatment and outcome are also presented. The importance of recognizing and treating this disorder in burn victims is discussed. Treatment results in improved compliance through all phases of therapy and an overall decrease in patient morbidity, especially psychologic problems. The need for psychiatric consultation, evaluation, and follow-up of the burn victim is emphasized.

Myocardial infarction in a child with Salmonella enterocolitis.

The case history and findings of a seven-month-old North American Indian girl with myocardial infarction following a prolonged febrile seizure associated with Salmonella typhimurium enterocolitis are presented and discussed. This appears to be a unique observation not previously described in the literature.