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Hyperbaric oxygen has been advocated, both as an adjunctive or primary form of treatment, for a variety of disorders, including gas gangrene, osteoradionecrosis, and carbon monoxide poisoning. It has also been used to improve ischemic wounds before skin grafting and to support ischemic flaps. In this review, we analyze the available literature that investigates the use of hyperbaric oxygen for composite grafts, skin grafts, random flaps, distant flaps, and free flaps. An appraisal of the level of evidence for each of these uses of hyperbaric oxygen is offered. Although there are a significant amount of animal data supporting the application of hyperbaric oxygen for grafts and flaps, there is very little clinical information other than case reports and series to sustain its choice over other modalities of therapy. Multicenter prospective clinical studies are clearly needed comparing hyperbaric oxygen to other mechanical or pharmacologic interventions to improve wound healing for grafting or to support flap survival.

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Parasacral hernias are defects through the pelvic floor which occur as the result of sacral resection. These defects are often large, and are frequently the result of treatment for sacral malignancies. This report documents the case of a 71-year-old woman who underwent radical coccygectomy and partial sacrectomy for a chordoma and subsequently presented 1 year later with a large parasacral hernia. The defect was repaired using an acellular human dermis graft with a gluteus maximus muscle-advancement flap overlay. This article summarizes the current literature of this challenging clinical problem, and examines the use of acellular human dermis in the repair of complex hernias.

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The insertion of a foreign substance, such as a breast implant into mammalian soft tissues, evokes a wound healing response that culminates in a dense connective-tissue envelope or capsule surrounding the implant. Several biodegradable products, such as Seprafilm (carboxymethylcellulose and hyaluronic acid) and Interceed (oxidized regenerated cellulose), have been demonstrated to inhibit adhesions in abdominal and gynecologic surgery. The ability of these cellulose compounds to inhibit capsule formation was addressed in this investigation. Twenty-eight rats were implanted intermuscularly with either plain silicone discs (10 animals), discs wrapped in Seprafilm (10 animals), or discs covered with Interceed (8 animals). Additional control animals (6 animals) consisted of two that had sham operations, two animals implanted with Seprafilm only, and two more implanted with Interceed only. Animals were sacrificed in pairs at varying time intervals after implantation (2, 4, 8, 12, and 16 wk), and the tissues around the silicone discs were analyzed with light microscopy. Control animals were sacrificed at 8 wk. Both Interceed and Seprafilm slowed the formation of a capsule around the implanted silicone discs as both products were degraded. Evidence of residual material, presumably Seprafilm and Interceed, was seen intracellularly in animals 3 to 4 mo, respectively, after implantation. However, neither material prevented the eventual formation of a fibrous capsule around the silicone discs. The results of this study suggest that encapsulating foreign substances with these types of biodegradable materials will not significantly hinder capsule formation. A more direct attack on the wound healing mechanism may provide a definitive solution for capsule problems with implanted materials.

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Our objective was to validate the use of an ultrasonic transit-time flowmeter for the measurement of portal blood flow (PBF) in sheep. Data recorded with this technique were compared with those obtained with an indicator dilution method, and probes were calibrated in vivo. Wethers were fitted with catheters in the portal, jejunal, and ruminal veins and in a mesenteric artery. Ultrasonic flow probes were implanted around the portal vein: S-series probes in three wethers, and A-series probes in four wethers. The PBF measured with A-series probes was within 10% of that measured by indicator dilution, but PBF measured with S-series probes were 52 to 77% of that determined by indicator dilution. In vivo calibration indicated that A-series probes provided accurate measurement of PBF (absolute accuracy: 5%+/-zero flow error). In conclusion, an ultrasonic transit-time flowmeter, with an A-series probe, can be used to reliably measure PBF in sheep.

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Twenty consecutive children, ranging in age from 6 days to 18 years, were treated with skeletal expansion, in addition to soft-tissue reduction, for medically refractory obstructive sleep apnea. The underlying diagnoses were craniofacial microsomia (n = 6), Down syndrome (n = 3), Pierre Robin syndrome (n = 3), cerebral palsy (n = 3), Nager's syndrome (n = 1), Treacher Collins syndrome (n = 1), cri du chat syndrome (n = 1), juvenile rheumatoid arthritis (n = 1), and temporomandibular joint ankylosis (n = 1). Fourteen children had severe medically refractory sleep apnea and were tracheostomy candidates; in the remaining six, tracheostomies were placed shortly after birth and could not be decannulated. Overnight, 12-channel polysomnography was obtained before and after surgery. The mean apnea index improved from 7.42 to 1.26, the mean respiratory disturbance index improved from 25.24 to 1.72, and the mean lowest apnea-related oxygen saturation improved from 68% to 88%. Of the 14 children with medically refractory obstructive sleep apnea, two required tracheostomies. Of the six patients with tracheostomies, five have been decannulated at the time of this writing. Skeletal expansion in conjunction with soft-tissue reduction in the pediatric population permits substantial increases in the volume of both the nasopharynx and oropharynx. Creative use of conventional osteotomies and the application of distraction osteogenesis have enabled surgeons to apply maxillofacial and craniofacial techniques in treating children with obstructive sleep apnea.

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To date, a paucity of information is available on the optimal management of obstructive sleep apnea in Down syndrome, which may have particularly important implications in this already vulnerable patient population. The objective of this study was to evaluate prospectively the results of a new surgical approach for the treatment of obstructive sleep apnea. Patients with Down syndrome and obstructive sleep apnea underwent preoperative and postoperative polysomnography and clinical and radiologic evaluation to determine prospectively the efficacy of sleep apnea surgery. Statistical testing of apnea index, respiratory disturbance index, and lowest oxygen saturation were compared by means of paired t tests. Seven children (five boys, two girls) from 3 to 12 years of age were subjected to a management protocol that included an aggressive surgical approach to the treatment of obstructive sleep apnea. Clinical symptoms and signs of obstructive sleep apnea, apnea index, respiratory disturbance index, lowest oxygen saturation, and surgical morbidity were the main outcome measures. Surgical treatment consisted of a combination of soft-tissue and skeletal alterations including tongue reduction (n = 6), tongue hyoid advancement (n = 4), uvulopalatopharyngoplasty (n = 7), and maxillary or midface advancement (n = 2). Polysomnography was obtained preoperatively and postoperatively in six patients. One patient was intubated preoperatively. Mean preoperative apnea index and respiratory disturbance index were 34.00 and 52.46 compared with mean postoperative values of 1.62 and 6.46, respectively. Clinically, all patients were improved symptomatically in terms of snoring, noisy breathing, and oxygen requirements. The one patient who had been intubated preoperatively for respiratory failure was extubated successfully but later developed recurrent tricuspid regurgitation and was found to have fixed pulmonary hypertension with cor pulmonale. This patient represented the only treatment failure and underwent tracheostomy. An aggressive surgical approach aimed at correcting all anatomic abnormalities associated with upper airway obstruction was applied successfully to the treatment of obstructive sleep apnea in Down syndrome. We suggest periodic polysomnography in patients with Down syndrome, especially if there is unexplained deterioration in mental capacity or other signs and symptoms of obstructive sleep apnea. Surgical treatment should address both the soft-tissue abnormalities and the skeletal deformities such as midface retrusion. Preoperative cardiac ultrasonography is important to determine the presence of right-sided heart failure, which may be an indication for cardiac catheterization to determine pulmonary venous pressures.

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Children with cerebral palsy are at risk of developing obstructive sleep apnea, which is initially managed by medical therapy but often requires tracheostomy for stabilization of the airway. We report preoperative and postoperative polysomnographic findings in a prospective series of 18 patients with cerebral palsy and obstructive sleep apnea who were refractory to medical management and underwent aggressive surgical treatment of upper airway obstruction. Fifteen of the 18 children (83 percent) in whom tracheostomy was recommended were spared the procedure. Eighteen children with cerebral palsy failed medical management of obstructive sleep apnea and were advised to have tracheostomy. There were 9 boys and 9 girls, ranging in age from 9 months to 17 years and 6 months at the time of operation. Tonsillectomy and adenoidectomy was performed in 9 patients, turbinectomy and/or septoplasty in 9, tongue-hyoid advancement in 13, uvulopalatoplasty in 13, conventional mandibular advancement in 2, distraction osteogenesis of the mandible in 2, and tongue reduction in 7. A concomitant Wilkes-Brody procedure for drooling was performed in 6 patients. Preoperative and postoperative polysomnographic data were compared by means of a paired t test. The mean preoperative apnea index, respiratory disturbance index, and lowest oxygen saturation were 3.61, 7.02, and 73.7, respectively. Mean postoperative apnea index, respiratory disturbance index, and lowest oxygen saturation were 0.67, 1.44, and 88.2, respectively. Lowest oxygen saturation and respiratory disturbance index were both improved significantly, with p values of 0.0367 and 0.0021, respectively. Fifteen patients are tracheostomy-free (83 percent) at a mean follow-up time of 30 months (range 14 to 49 months.) Two (11 percent) of the children ultimately required tracheostomy, and one (6 percent) died from respiratory failure following the parents' decision not to proceed with further treatment. Our results confirm the efficacy of an aggressive surgical approach to the treatment of obstructive sleep apnea in neurologically compromised children. Many children and their families may potentially avoid the long-term commitment and cumulative hazards of tracheostomy. Additional strategies that have been adopted include identification and aggressive management of seizures, esophageal reflux, and excessive oral secretions and the application of mandibular distraction and skeletal expansion whenever feasible. Close postoperative monitoring is necessary with reoperation for recurrent symptoms of obstructive sleep apnea if documented by sleep study and associated with evidence of recurrent or residual morphologic abnormalities.

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OBJECTIVE: When a patient presents with velopharyngeal incompetence (VPI) without an obvious structural or neurologic cause, the clinician is faced with a diagnostic challenge. We present an 11-year-old male with a long history of VPI who had been referred to our institution for evaluation and treatment. RESULTS: Detailed clinical examination and work-up revealed a malignant brainstem tumor. The presenting symptoms of breathiness associated with VPI had been overlooked by several different clinicians in the past. The patient successfully underwent a sphincter pharyngoplasty. CONCLUSIONS: A careful neurologic examination with special attention to the cranial nerves is necessary to identify subtle neurologic deficits and avoid delay in diagnosis. Differential diagnosis of neurogenic VPI is discussed.

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Coral and hydroxyapatite may be used as substitution biomaterials for bone grafts. In this work, we extracted the implants from the femora to study the kinetics of elementary mineral transformation of the osseous substitutes. The use of physical analysis methods such as PIXE (particle-induced X-ray emission) shows that coral and hydroxyapatite, after their implantation in vivo, reach a mineral composition comparable with that of bone. For the first time we have measured the concentration of mineral elements, at different time intervals after implantation, along a cross-section. The distribution according to mineral elements (Ca, P, Sr, Zn, Fe) in the implant, in the receiver site and also at the interface, showed that the kinetics of coral resorption was faster than that of hydroxyapatite; in the same way, the osseous attack was not global but, rather, centripetal.

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Two adult sheep, A and B, received successively during three experimental periods a forage-based pelleted feed, then the same diet supplemented with 33 mg/kg of lasalocid (L) or cationomycin (C). The feed was given in either eight (sheep A) or two (sheep B) daily meals. After four weeks of adaptation, 11 blood samples were taken through catheters in the rumen vein (RVA) and the mesenteric artery (MAA) in sheep A and in the rumen vein (RVB) and portal vein (PVB) in sheep B over a 5-hour period after the morning meal. Because of a blockage in the catheter it was not possible to measure the effect of C in MAA. Food intake had no immediate effect on the plasma levels measured: the distribution of eight daily meals stabilized plasma levels and made it easier to determine the effect of the ionophores. This effect varied according to the sampling site, the animal and the antibiotic, sometimes contradictorily. All the plasma parameters monitored in RVA were significantly modified by either one of the ionophores. A decrease in plasma albumin concentration (P < 0.05) was observed with L in MAA and with C in RVA and MAA. Aceto-acetate concentration decreased (P < 0.05) with L in MAA but increased with L and C in RVB. A decrease in glycaemia and uraemia (P < 0.05) was observed with L in MAA, RVA and RVB and with C in RVA. Total amino acid concentration decreased (P < 0.05) with C in RVA or increased (P < 0.05) with L in PVB and RVB. These variations in results may be due to different mechanisms of action of L and C on digestion, particularly in the rumen. While the changes undergone by the ketone bodies in the blood suggested a decrease in hepatic ketogenesis with L, there was no evidence that the ionophores had a direct postprandial effect.

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It has been demonstrated that parathyroid hormone-related peptide (PTHrP) stimulates calcium (Ca) placental transport. Ca and inorganic phosphorous (P) metabolisms are intimately linked. Thus we have studied the influence of PTHrP on P placental transport in ewes. In our experimental paradigm, synthetic human PTHrP (1-86) fragment intravenously injected in six single chronically catheterized fetuses (3 x 1 micrograms/fetus/day, from day 129 to day 140 of gestation) had no significant effect upon P placental transport which was 131 +/- 6 and 129 +/- 9 mg/kg fetal weight/day in treated and control fetuses, respectively.

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Amino-terminal fragments of PTHrP were previously shown to increase regional blood flow in laboratory animals. Since PTHrP is produced in the lactating mammary gland and associated nutrient vessels, we examined the effects of peptide fragments of PTHrP on the hemodynamics of the mammary gland of dried sheep. The left arterial mammary blood flow measured using ultrasonic flow probes in four dried Lacaune ewes was 233 +/- 11 ml/minute. It was significantly increased when synthetic human PTHrP-(1-34) or (1-86) fragments were injected into the mammary artery. The effect was dose dependent for PTHrP-(1-34), varying between 0.0075 and 0.3 nmol/kg body weight. PTHrP-(140-173) fragment lacked any vasorelaxant activity. Synthetic human endothelin (ET1) decreased arterial blood flow in a dose-dependent manner. This decrease was inhibited by PTHrP-(1-34), and this inhibition was PTHrP dose related. When ET1 (10 pmol/kg body weight) was injected together with PTHrP-(1-86) (100 pmol/kg body weight), only a significant increase in mammary blood flow was observed. Thus, PTHrP produced by the lactating mammary gland may be involved in the regulation of mammary blood flow.

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Eight wethers were used to test the technique. Silicone rubber catheters were introduced into both ruminal veins so that their tips lay a few centimeters from the splenic vein. Arterial blood flow to the rumen was measured by an ultrasonic transit-time flow meter with 3-mm probes implanted around the left and right ruminal arteries. No loss of patency of the venous catheters was observed before slaughter (2 to 6 mo after surgery). There was no evidence of extensive vascular trauma due to catheterization at postmortem examination. In vivo calibration of the flow probes showed that reliable measurements could be made until at least 6 mo after implantation. With an accurate method of blood flow measurement in ruminal arteries and guaranteed long-term catheter patency, it would be possible to make reliable estimates of nutrient uptake across the ruminal wall of sheep over an experimental period of several months.

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Four young milk-fed calves were fitted with catheters chronically implanted in the mesenteric, portal and hepatic veins and in the hepatic artery. Electromagnetic blood flow probes in the portal vein and hepatic artery allowed continuous measurement of hepatic IGF-1 production. In accordance with a latin square design these calves received iv mesenteric infusion (for 60 min) of calcium (Ca, 0.125 mmol.kg body wt-1), the synthetic human parathyroid hormone-related protein (1-34) fragment (PTHrP, 1 nmol.kg body wt-1), the synthetic analogue [tyr]34-bovine PTH-(7-34) NH2 (2 nmol.kg body wt-1) and PTHrP (1 nmol.kg body wt-1) or solvent alone (1.2 ml.kg body wt-1). Hypercalcaemia observed following Ca infusion had no significant effect on hepatic IGF-1 production. PTHrP induced a slight but significant increase in plasma Ca and IGF-1 concentrations measured in the hepatic vein, without changing blood flows measured in the hepatic artery and portal vein. Thus PTHrP increased hepatic IGF-1 production (15.1 +/- 2.7 nmol.6 h-1.kg body wt-1 vs 4 +/- 1.3 nmol.6 h-1.kg body wt-1 in controls; p less than 0.05). These effects induced by PTHrP were inhibited by the synthetic analogue [tyr]34-bPTH-(7-34) NH2.

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The effect of synthetic human parathyroid hormone-related peptide fragment 1-34 (hPTHrP) on plasma concentration and urinary excretion of inorganic phosphorus (P) was compared to that of synthetic bovine PTH fragment 1-34 (bPTH) in four 120- to 130-day-old fetal lambs chronically catheterized in utero. They received by I.V. infusion according to a Latin square design either bPTH (6 nmol per fetus) or hPTHrp (6 nmol per fetus) alone, or after the synthetic analogue [Tyr34]bPTH(7-34)NH2 (12 nmol per fetus). Control fetuses received the same volume of solvent alone. Both bPTH and hPTHrP stimulated diuresis. They induced hypercalcaemia, hyperphosphaturia and hypophosphataemia. The effects of hPTHrP were inhibited by [Tyr34]bPTH(7-34)NH2, indicating that PTHrP might work through the PTH receptor.

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Lipogenic activities of perirenal adipose tissue were investigated in early (wk 3) and midlactation (wk 19 to 26) cows that received a duodenal rapeseed oil infusion (1.0 to 1.1 kg/d). In midlactation, oil infusion resulted in a decreased rate of fatty acid synthesis from acetate and a decreased rate of the activities of fatty acid synthetase and glucose-6-phosphate dehydrogenase, whereas lipoprotein lipase activity tended to increase. The rate of glucose incorporation into glyceride-glycerol and the activities of glycerol-3-phosphate dehydrogenase and malic enzyme were not significantly affected. Fatty acid C14:0 content of perirenal adipose tissue was decreased, and fatty acid C18:2 and C18:3 contents were increased in oil-infused cows. In early lactation, rates of acetate incorporation into fatty acids and activities of fatty acid synthetase and lipoprotein lipase were very low. Activities of glucose-6-phosphate dehydrogenase and glycerol-3-phosphate dehydrogenase were lower in the early than in the midlactation trial. Oil infusion did not change the measured parameters. In both trials, percentages and yields of milk fatty acids C18:1, C18:2, and C18:3 were increased, whereas those of C14:0 and C16:0 were decreased by oil. Calculated transfer rates of absorbed fatty acid C18:2 from oil to milk fat were 16 to 26%. Results suggested that oil fatty acids affected adipose and mammary de novo lipogenesis in a direct way without affecting fatty acid esterification in adipose tissue or total fat secretion in mammary tissue.

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Three preruminant calves were fitted with catheters in portal and hepatic veins and in a mesenteric artery. Two electromagnetic flowmeter probes were clipped around the portal vein and the hepatic artery. The calves were fed either a diet with a low (L) or a high (R) abomasal emptying rate for dietary proteins. Blood flow and free amino acid levels in plasma (P) and blood (S) were determined before the morning meal and during the following 7 h. In the portal vein, for most amino acids P/S ratios were correlated to the net amino acid balance of the digestive tract measured in plasma. By contrast in the hepatic vein, these ratios were mainly correlated to hepatic balance measured in whole blood. Correlations between digestive tract and hepatic balance calculated using either plasma or whole blood pool were different for some amino acids. This suggests that amino acid exchange between plasma and blood cells is low and absorbed amino acids are mainly transported to the liver by plasma, whereas whole blood rather than plasma is concerned in amino acid exchanges in the liver.

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Remnants of the fusion of fetal renunculi have been mistaken for renal scars or tumors. We compared anatomic cuts of 24 cadaveric kidneys with fetal lobation (ages ranged from 16 weeks gestation to 49 years) to identical ultrasonographic sections performed in a water bath and to sonograms of healthy persons of similar ages as the cadavers. Fetal lobation was characterized as follows: there were fine, linear demarcations indenting the renal surface, separating normal lobes, consisting of a central pyramid and surrounding cortex. Separate renunculi seen in early fetal life progressively fuse throughout gestation, leaving interlobar grooves. During the third trimester, the renal surface becomes smoother and the interlobar grooves become invisible. One prominent indentation of the renal surface, the interrenuncular junction, incorporates perirenal fat and invaginates the anterior surface of the upper third of the kidney to the hilum and is the most easily visible remnant of fetal lobation. The sharply defined linear remnants of interlobar grooves should not be mistaken for scars, which are wider, less well defined and always associated with loss of renal cortex.

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A method of continuous in vivo flow measurement of plasma metabolites through the liver in calves was described. Five 2-wk old male calves were fitted with chronic catheters in the hepatic and portal veins and in the hepatic artery and with electromagnetic blood flow probes in the portal vein and in the hepatic artery. The reliability of measurements was tested during a 3-wk period in which calves were fed milk diets that curdled or did not curdle (uncurdled) in the abomasum. In comparison with a conventional curdled milk diet, the intake of uncurdled milk diet did not modify mean portal vein (47 to 49 ml.mn-1.kg live weight-1) or hepatic arterial (5.6 to 5.7 ml.mn-1.kg live weight-1) blood flows but did influence nycthemeral variations in portal blood flow rates, especially during the second part of the night.

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