Diagnosis and severity criteria for sinusoidal obstruction syndrome/veno-occlusive disease in pediatric patients: a new classification from the European society for blood and marrow transplantation

The advances in hematopoietic cell transplantation (HCT) over the last decade have led to a transplant-related mortality below 15%. Hepatic sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) is a life-threatening complication of HCT that belongs to a group of diseases increasingly identified as transplant-related, systemic endothelial diseases. In most cases, SOS/VOD resolves within weeks; however, severe SOS/VOD results in multi-organ dysfunction/failure with a mortality rate >80%. A timely diagnosis of SOS/VOD is of critical importance, given the availability of therapeutic options with favorable tolerability. Current diagnostic criteria are used for adults and children. However, over the last decade it has become clear that SOS/VOD is significantly different between the age groups in terms of incidence, genetic predisposition, clinical presentation, prevention, treatment and outcome. Improved understanding of SOS/VOD and the availability of effective treatment questions the use of the Baltimore and Seattle criteria for diagnosing SOS/VOD in children. The aim of this position paper is to propose new diagnostic and severity criteria for SOS/VOD in children on behalf of the European Society for Blood and Marrow Transplantation.

Comparative lipoplasty analysis of in vivo-treated adipose tissue

A comparative histologic and chemical analysis was undertaken of adipose tissue treated in vivo with traditional, ultrasound-assisted, and external ultrasound-assisted lipoplasty. A series of six healthy women undergoing elective liposuction according to the superwet technique using a 1:1 infiltration ratio with the estimated quantity of fat to be removed was included in the study. Four separate regions on each patient were treated independently in vivo with traditional liposuction, internal ultrasound-assisted liposuction, or external ultrasound-assisted liposuction for 7 minutes. External massage was used as a control. Four separate specimens of adipose tissue from each patient were assessed for cellular disruption using blinded histologic evaluation. The remainder of tissue was centrifuged to separate the aqueous phase from the cellular components and then spectrophotometrically analyzed for creatinine kinase and glycerol 3-phosphate dehydrogenase activity as markers of cellular disruption. Histologic analysis confirmed 70 to 90 percent cellular disruption with internal ultrasound-assisted liposuction. Suction-assisted and external ultrasound-assisted liposuction showed 5 to 25 percent disruption, whereas massage controls showed only 5 percent. Only internal ultrasound-assisted liposuction showed 5 to 20 percent thermal liquefaction. Absorbance analysis showed creatine kinase activity (sigma units) greatest in ultrasound-exposed tissue. Both external and internal ultrasound-assisted liposuction gave creatine kinase levels 28 to 33 percent greater than suction-assisted liposuction, which varied only 10 percent from controls. Glycerol 3-phosphate dehydrogenase activity was 44 percent greater for internal ultrasound-assisted liposuction than that detected with suction-assisted liposuction. Glycerol 3-phosphate dehydrogenase activity with external ultrasound-assisted liposuction and massage did not vary much from each other, at only 14 percent and 11 percent activity compared with internal ultrasound-assisted liposuction, respectively. Histologic and enzyme analysis of the different types of liposuction and their effect on adipocyte cellular disruption revealed no significant effect of external ultrasound or massage on the adipocytes. Further experimental studies are necessary to evaluate the role and efficacy of alternative techniques for body contouring.

Road traffic accidents in Saudi Arabia

Road traffic accidents are a major health hazard in Saudi Arabia, particularly during Ramadan. The ensuing trauma has increased in direct proportion to the increase in the number of road vehicles. An audit of RTAs over a one-year period revealed that, out of 361 victims, 16% were under 10 years and 47% between 11 and 30 years. None of those involved in accidents was wearing a seat belt. Half of the children injured were pedestrians. There was a male to female ratio of 4:1 reflecting the driving laws in Saudi Arabia. Burst tyres due to intense heat were identified as a common cause (39%) of accidents. The introduction of seat belt legislation and stricter law enforcement should lead to a rapid reduction in morbidity and mortality on the roads in Saudi Arabia.

Effect of glycaemic control on apoptosis in diabetic wounds

OBJECTIVE

To study the effect of glycaemic control on apoptosis in chronic ulcers in diabetic patients and the differential roles of insulin and oral hypoglycaemic agents (OHAs).

METHOD

Ten non-diabetic (group I) and 20 diabetic patients (groups II and III), with a wound of more than four weeks' duration, who were attending the wound clinic at University Hospital, Varanasi, India were recruited. The 10 patients in group 11 received insulin and the 10 in group III an oral hypoglycaemic agent; all had diabetic foot ulcers. Wound biopsy and other routine investigations were performed. Both DNA fragmentation and morphological changes under light microscopy (apoptotic index) were used as determinants of apoptosis. Different variables, including fasting and post-prandial blood sugar, serum low-density lipoprotein (LDL) and markers of microangiopathy, such as proteinuria and diabetic retinopathy, were compared with apoptosis.

RESULTS

DNA fragmentation in groups I, II and III was 40.00 +/- 2.97, 45.26 +/- 3.21 and 60.8 +/- 3.13 respectively (p < 0.01). Near linear correlation was observed with blood sugar level, particularly post-prandial blood sugar (p < 0.05) and DNA fragmentation. DNA fragmentation was significantly correlated with serum LDL and proteinuria, and it was much greater in the OHA group than in the insulin group (p < 0.05). Similarly, in the diabetic patients with background retinopathy the DNA fragmentation was 46.50 +/- 3.42 (n=3) in the insulin group and 66.70 +/- 6.48 (n=4) in the OHA group (p < 0.05).

CONCLUSION

There is a significant increase in apoptosis in diabetic wounds with poorly controlled blood sugar and microangiopathy. This increase was greater in patients on OHAs than those on insulin, and it contributes to delayed wound healing. Morphological markers do not appear to be a reliable index of apoptosis in the diabetic wound.

Fertility preservation issues in pediatric hematopoietic stem cell transplantation: practical approaches from the consensus of the Pediatric Diseases Working Party of the EBMT and the International BFM Study Group

Fertility preservation is an urgent challenge in the transplant setting. A panel of transplanters and fertility specialists within the Pediatric Diseases Working Party of the European Society for Blood and Marrow Transplantation (EBMT) and the International BFM Study Group provides specific guidelines. Patients and families should be informed of possible gender- and age-specific cryopreservation strategies that should be tailored according to the underlying disease, clinical condition and previous exposure to chemotherapy. Semen collection should be routinely offered to all postpubertal boys at the diagnosis of any disease requiring therapy that could potentially impair fertility. Testicular tissue collection might be offered to postpubertal boys; nevertheless, its use has been unsuccessful to date. Oocyte collection after hormonal hyperstimulation should be offered to postpubertal girls facing gonadotoxic therapies that could be delayed for the 2 weeks required for the procedure. Ovarian tissue collection could be offered to pre-/post-pubertal girls. Pregnancies have been reported after postpubertal ovarian tissue reimplantation; however, to date, no pregnancy has been reported after the reimplantation of prepubertal ovarian tissue or in vitro maturation of pre-/post-pubertal ovarian tissue. Possible future advances in reproductive medicine could change this scenario. Health authorities should prioritize fertility preservation projects in pediatric transplantation to improve patient care and quality of life.

Entry Flow of Polyethylene Melts in Tapered Dies

The excess pressure losses due to end effects (mainly entrance) in the capillary flow of several types of polyethylenes were studied both experimentally and numerically under slip and no-slip conditions. These losses were first measured as a function of the contraction angle ranging from 15° to 90°. It was found that the excess pressure loss attains a local minimum at a contraction angle of about 30° for all types of polyethylenes examined. This was found to be independent of the apparent shear rate. This minimum becomes more dominant under slip conditions that were imposed by adding a significant amount of fluoropolymer into the polymer. Numerical simulations using a multimode K-BKZ viscoelastic model have shown that the entrance pressure drops can be predicted fairly well for all cases either under slip or no-slip boundary conditions. The clear experimental minimum at about 30° can only slightly be seen in numerical simulations, and at this point its origin is unknown. Further simulations with a viscous (Cross) model have shown that they severely under-predict the entrance pressure by an order of magnitude for the more elastic melts. Thus, the viscoelastic spectrum together with the extensional viscosity play a significant role in predicting the pressure drop in contraction flows, as no viscous model could. The larger the average relaxation time and the extensional viscosity are, the higher the differences in the predictions between the K-KBZ and Cross models are.

The association of rate pressure product (RPP) and myocardial perfusion imaging (MPI) findings: a preliminary study

Introduction: The product of heart rate and systolic blood pressure, termed as rate-pressure product (RPP), is a very reliable indicator of myocardial oxygen demand and is widely used clinically. There have been previous attempts to describe the relationship between RPP and the onset of pain in angina pectoris. The current study aimed to evaluate the association between RPP results and scan findings.

Materials and methods: In total, 497 patients with suspected coronary artery disease (CAD) underwent gated, single-photon emission computed tomography (SPECT) imaging with dipyridamole, exercise, or dobutamine stress, and were included in this study. Baseline and maximum heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and electrocardiogram (ECG) results were recorded. The rate-pressure product (RPP) was calculated as the product of heart rate and systolic arterial pressure for both baseline and maximum measures. The difference between the RPP max and the basal RPP is known as the RPP reserve. Researchers also obtained semi-quantitative analyses of myocardial perfusion imaging (MPI), using gated software, demographic information, risk factors of CAD, and pretest likelihoods of CAD using nomograms.

Result: Four hundred and ninety-seven cases, including 426 patients with dipyridamole stress, 59 with exercise stress, and 12 with dobutamine stress, underwent myocardial perfusion imaging. Scan results were positive in 194 (45.5%) and negative in 232 (54.5%) patients with dipyridamole stress. In patients with exercise stress, the scan was positive in 24 (40.7%) cases and negative in 35 (59.3%) cases. In dobutamine stressed patients, the scan was positive in 6 (50%) cases and negative in the 6 remaining cases. Dipyridamole stress resulted in a significant difference between HR at rest and at maximum (28.95 ± 24.53, p-value<0.0001), between systolic BP at rest and maximum (6.75 ± 12.50, p-value<0.0001) and between diastolic BP at rest and maximum (1.45 ± 5.80; p-value<0.0001). There was a significant correlation between sum stress scores (SSS) and reserved RPP (r= −0.12, p-value<0.001) which, in dipyridamole patients, was r=−0.18, p-value=0.0001). In addition, there was a significant association between reserved RPP and risk of CAD (p-value<0.001). In the patients with dipyridamole stress, the ejection fraction (EF) change (odds ratio =0.92; 95% CI: 0.86-0.98; p=0.01), reserve RPP (odds ratio =1.00; 95% CI: 1.00-1.00; p=0.04), risk of CAD (odds ratio =5.80; 95% CI: 3.21-10.50; p<0.0001) and age (odds ratio =0.94; 95% CI: 0.89-0.98; p=0.01) were associated significantly with MPI results, using multiple logistic regressions.

Conclusion. The study demonstrated that RPP is associated with MPI findings using gated SPECT imaging with dipyridamole stress. However, to confirm this preliminary result, further studies are mandatory.

The impact of T-cell depletion techniques on the outcome after haploidentical hematopoietic SCT

Several T-cell depletion (TCD) techniques are used for haploidentical hematopoietic SCT (HSCT), but direct comparisons are rare. We therefore studied the effect of in vitro TCD with graft engineering (CD34 selection or CD3/CD19 depletion, 74%) or in vivo TCD using alemtuzumab (26%) on outcome, immune reconstitution and infections after haploidentical HSCT. We performed a retrospective multicenter analysis of 72 haploidentical HSCT in Switzerland. Sixty-seven patients (93%) had neutrophil engraftment. The 1-year OS, TRM and relapse incidence were 48 (36-60)%, 20 (11-33)% and 42 (31-57)%, respectively, without differences among the TCD groups. In vivo TCD caused more profound lymphocyte suppression early after HSCT, whereas immune recovery beyond the second month was comparable between the two groups. Despite anti-infective prophylaxis, most patients experienced post-transplant infectious complications (94%). Patients with in vivo TCD had a higher incidence of CMV reactivations (54% vs 28%, P=0.015), but this did not result in a higher TRM. In conclusion, TCD by graft engineering or alemtuzumab are equally effective for haploidentical HSCT.

Influence of glutathione S-transferase gene polymorphisms on busulfan pharmacokinetics and outcome of hematopoietic stem-cell transplantation in thalassemia pediatric patients

Hematopoietic stem-cell transplantation (HSCT) is currently the only curative therapeutic option for the treatment of thalassemia. In spite of the high cure rate, HSCT can lead to life-threatening adverse events in some patients. Busulfan (Bu) is a key component of the conditioning regimen prior to HSCT. Inter-individual differences in Bu pharmacokinetics (PK) are hypothesized to influence Bu efficacy and toxicity. Since Bu is mainly metabolized by glutathione S-transferase (GST), we investigated the relationship of GSTA1 and GSTM1 genotypes with first-dose PK and HSCT outcomes in 44 children with thalassemia intermedia and thalassemia major. All children received a myeloablative conditioning regimen with IV Bu. Association analysis revealed a relationship between GSTA169C>T (or haplotype *A/*B) and first Bu dose PK that was dependent on sex and Pesaro risk classification (PRC). Among female patients and patients with PRC I-II, homozygous individuals for the GSTA1T-69 allele defining haplotype *B, had higher Bu exposure and lower clearance (P⩽0.01). Association with HSCT outcomes showed that patients with the GSTM1 null genotypes had higher occurrence of regimen-related toxicity (P=0.01). These results suggest that GST genotypes could be useful to tailor the first Bu dose accordingly to improve HSCT outcome.

The association of cytochrome P450 genetic polymorphisms with sulfolane formation and the efficacy of a busulfan-based conditioning regimen in pediatric patients undergoing hematopoietic stem cell transplantation

Cytochrome P450 enzymes (CYPs) and flavin-containing monooxygenases (FMOs) likely have a role in the oxidation of intermediate metabolites of busulfan (Bu). In vitro studies to investigate the involvement of these enzymes are cumbersome because of the volatile nature of the intermediate metabolite tetrahydrothiophene (THT) and the lack of sensitive quantitation methods. This study explored the association between the CYP2C9, CYP2C19, CYP2B6 and FMO3 genotypes and sulfolane (Su, a water soluble metabolite of Bu) plasma levels in children undergoing hematopoietic stem cell transplantation (HSCT). The relationship between these genotypes and the effectiveness of myeloablative conditioning was also analyzed. Sixty-six children receiving an intravenous Bu-based myeloablative conditioning regimen were genotyped for common functional variant alleles in CYP2C9 (*2 and *3), CYP2C19 (*2 and *17), FMO3 (rs2266780, rs2266782 and rs1736557) and CYP2B6 (*5 and *9). The plasma levels of Bu and its metabolite Su were measured after the ninth Bu dose in a subset of 44 patients for whom plasma samples were available. The ratio of Bu to Su was considered the metabolic ratio (MR) and was compared across the genotype groups. Higher MRs were observed in CYP2C9*2 and *3 allele carriers (mean±s.d.: 7.8±3.6 in carriers vs 4.4±2.2 in non-carriers; P=0.003). An increased incidence of graft failure was observed among patients with an MR>5 compared with those with MR values <5 (20% vs 0%; P=0.02). In contrast, a significantly higher incidence of relapse and graft failure (evaluated as event-free survival) was observed in patients with malignant disease who carried CYP2B6 alleles with reduced function on both chromosomes compared with carriers of at least one normal allele (100% vs 40%; P=0.0001). These results suggest that CYP2C9 has a role in the oxidation reactions of THT and indicate that it may be possible to predict the efficacy of Bu-based myeloablative conditioning before HSCT on the basis of CYP genotypes and Bu MRs.

Association between comorbidity and erectile dysfunction in patients with diabetes

The aims of this study were to determine the prevalence of erectile dysfunction (ED) and its relationship with comorbidity in patients with diabetes. The study population comprised of 312 consecutive patients aged 20 years or over residing in the city of Hamadan in Iran in 2005. Depression was assessed by the modified version of the Beck Depression Inventory (BDI-II) and ED by the short form of the International Index of Erectile Function (IIEF-5) questionnaire. Potential confounding was controlled by stratification and by a logistic regression model. The prevalence of moderate or complete ED (IIEF score <or=11) was 34% and that of moderate or severe depressive symptoms 30%. Each 1-year increment in diabetes duration was associated with a 10% higher risk of ED. The risk of ED was higher in men with depression (odds ratio (OR)=10.7, 95% CI 5.4-21.1) and in those with cardiovascular disease (CVD) (OR=2.0, 95% CI 1.1-3.6). CVD was associated with ED only in elderly men, whereas depression was related to ED in both young and older subjects. The risk of ED was higher in subjects with both depression and CVD (OR=17.2, 95% CI 6.8-43.1 compared with men free from both diseases). Subjects who consumed fruits weekly or seldom had a higher risk of ED (OR=3.2) compared with those who consumed daily. Our study shows a strong association between depressive symptoms and ED. The association is much stronger for older men. Depression and CVD may interact with one another in relation to a higher risk of ED. A diet rich in fruits may have a beneficial effect on erectile function.

Development and progression of uremic changes in the mouse with surgically induced renal failure

Adult C57BL/6 mice with surgically induced renal failure of 1-15 weeks' duration were examined for the presence of changes caused by the renal failure. Surgery consisted of the electrocoagulation of the entire surface of the right kidney followed 3 weeks later by contralateral nephrectomy. Control groups comprised normal mice as well as sham-operated mice subjected to the right kidney electrocoagulation followed by visualization of the left kidney rather than removal. Results indicate: (1) the surgical procedures to induce renal failure were free of local and systemic infectious complications, (2) moderate to severe degree of renal failure was consistently achieved and remained stable over the study period, (3) significant growth retardation of the renal failure mice was present throughout the study whereas sham-operated mice showed catch-up growth with normal controls by the 3rd week postsurgery, (4) anemia was a very early manifestation of the disease appearing by the 1st week after the induction of renal failure to reach its nadir by the 2nd week; a mild anemia was observed transiently postsurgery in sham-operated mice and ascribed to the renal injury, and (5) renal failure mice were free of visible changes of advanced uremia such as impaired wound healing, bleeding tendency and gross neurological deficits. This new experimental model is proposed as a tool for the study of the pathogenesis and treatment of chronic uremia. While developed to study the immunological disturbances of renal failure, this model could conceivably serve for the study of other abnormalities, anemia in particular.

Managing atrial fibrillation in the Accident and Emergency department

We surveyed Accident and Emergency (A&E) consultants in England by questionnaire, on their management of patients presenting with AF. Completed questionnaires were received from 124 (45%). Most (42%) would use digoxin as first-line treatment for rate control of AF; 28% would not treat AF acutely but would refer the patient to the medical team; 59% would cardiovert a patient with AF in A&E, if there was evidence of cardiovascular compromise. Some 51% would not routinely initiate any anticoagulation therapy. Faced with a patient in fast AF who was haemodynamically unstable, 67% would immediately opt for electrical cardioversion, 13% would refer the patient directly to the medics and 15% would initially treat with intravenous digoxin. Given a patient in fast AF and cardiac failure, 55% would treat with digoxin. Asked about AF related to Wolff-Parkinson-White syndrome, 37% would initially give adenosine, 23% would opt for immediate DC cardioversion and 25% would refer directly to the medics; however, a minority would still give a rate-limiting calcium antagonist or digoxin. The majority (79%) would not treat AF in a known alcoholic with acute intoxication who was haemodynamically stable. Consultants were more likely to initiate treatment if the patient had signs of shock or heart failure. Where there were underlying medical problems they were more likely to refer the patient directly to the medical team. There was a general reluctance to initiate anticoagulation, and some difference in opinion over how long AF should have persisted for anticoagulation to be necessary in the context of electrical cardioversion. Given the current evolution of A&E as an acute speciality, A&E clinicians should at least initiate management of patients with AF and be prepared to care for them for some time in A&E.

Prevalence of multidrug-resistant and extended-spectrum beta-lactamase producing Gram-negative isolates from clinical samples in a tertiary care hospital of Nepal

BACKGROUND

The existence of multidrug-resistant organisms, including extended-spectrum beta-lactamases (ESBLs), is on rise across the globe and is becoming a severe problem. Knowledge of the prevalence and antibiogram profile of such isolates is essential to develop an appropriate treatment methodology. This study aimed to study the prevalence of Gram-negative isolates exhibiting ESBL at a tertiary care hospital and study their antibiogram profile.

METHODS

A cross-sectional study was conducted at Shahid Gangalal National Heart Centre, Kathmandu, Nepal, from June 2018 to November 2018. A total of 770 clinical samples were collected and identified using the conventional biochemical tests following the Clinical and Laboratory Standard Institute (CLSI) guidelines. Antimicrobial susceptibility testing (AST) was performed using the standardized Kirby-Bauer disk diffusion method. The screening test for ESBL producers was performed as recommended by the CLSI and the confirmatory test was performed phenotypically using the E-test.

RESULTS

Out of the 92 isolates, 84 (91.3%) were multidrug-resistant, and 47 (51.1%) were found to be potential ESBL producers. Of these, 16 isolates were confirmed ESBL producers by the E-test. Escherichia coli and Klebsiella pneumoniae were the predominant isolates and were also the major ESBL producers. Besides polymyxin B (100% sensitive), meropenem and imipenem showed high efficacy against the ESBL producers.

CONCLUSION

Multidrug resistance was very high; however, ESBL production was low. Polymyxin B and carbapenems are the choice of drugs against ESBL producers but should be used only as the last line drugs.

Extrudate Swell of High Density Polyethylenes in Slit (Flat) Dies

Extrudate swell of industrial-grade high-molecular mass high-density polyethylenes (HDPEs) in flat/slit dies is studied using both experiments and simulations. The experimental set-up consists of an optical micrometer to measure the extrudate dimensions and a pair of radiation heaters to control the extrudate temperature outside the die attached to the capillary rheometer. The simulation of extrudate swell phenomenon is carried out by using a well-known integral K-BKZ model. The effects of several rheological characteristics, die characteristics, and processing conditions on swell measurements are studied systematically, and the corresponding two-dimensional, steady-state numerical predictions are presented in this paper. This study includes the effects of polymer molecular characteristics, apparent shear rate, die geometrical characteristics (length to die gap (L/H) and width to die gap (W/H)), and distance from the die exit. It is found that the integral K-BKZ model predicts well both the width and thickness extrudate swells. Extrudate swell measurements demonstrate that the thickness swell is predominant in comparison with width swell.

Acute calcineurin inhibitor overdose: analysis of cases reported to a national poison center between 1995 and 2011

Transplant recipients and other patients requiring immunosuppression with calcineurin inhibitors or their household contacts may be exposed to overdose. This study investigated the circumstances, pharmacokinetics and outcomes of overdose with cyclosporine and tacrolimus reported to the Swiss Toxicological Information Centre between 1995 and 2011. Of 145,396 reports by healthcare professionals, 28 (0.02%) concerned enteral or parenteral overdose with these calcineurin inhibitors. Thirteen (46%) were iatrogenic errors, 12 (43%) were with suicidal intent and 3 (11%) were accidental. Iatrogenic overdoses usually involved noncapsule drug formulations. Acute enteral overdoses caused symptoms in a dose-dependent fashion but were generally well tolerated; the mean multiple of patient's usual dose was 20.8 ± 28.8 for symptomatic versus 4.4 ± 3.4 for asymptomatic cases (p = 0.037). The most common symptoms were nausea, headache, somnolence, confusion, hypertension and renal impairment. In contrast, acute intravenous overdoses were often poorly tolerated and resulted in one fatality due to cerebral edema after a cyclosporine overdose. Enteral decontamination measures were performed in six cases involving oral ingestion and appeared to reduce drug absorption, as shown by pharmacokinetic calculations. In the one case where it was used, pharmacoenhancement appeared to accelerate tacrolimus clearance after intravenous overdose.

The blood supply of the reverse temporalis muscle flap: anatomic study and clinical implications

Although the reverse temporalis muscle flap has been used clinically, the exact vascular connection between the superficial and deep temporal vessels has not been clearly defined. The purpose of this study was to investigate the vascular territory of the reverse temporalis muscle supplied by the superficial temporal vessels. Six cadaver heads were studied using a colored lead oxide injection through the superficial temporal artery. The specimens were examined macroscopically and radiographically. The reverse temporalis muscle flap was then applied to a clinical case presenting with traumatic anterior skull base defect communicating with the nasal cavity. The cadaver specimens demonstrated that the superficial temporal artery formed an average 1.3 +/- 0.2 cm in width of dense vascular zone, which was located within 1.8 cm below the superior temporal line. The dense vascular network further perfused the anterior and posterior deep temporal arteries and the muscular branch of the middle temporal artery to supply the temporalis muscle. The mean perfused area of the temporalis muscle was 83 percent, ranging from 79 to 89 percent, in five cadaver heads. One cadaver revealed only 55 percent of perfused area in the absence of the muscular branch of the middle temporal artery. The consistent area without perfusion was located in the distal third of the posterior portion of the reverse temporalis muscle. In clinical cases, the reverse temporalis muscle flap was used successfully to obliterate the anterior skull base defect without evidence of muscle flap necrosis. The exact blood supply to the distal third of the posterior portion of the reverse temporalis muscle flap needs to be investigated further in vivo. Particular attention was paid to the inclusion of the muscular branch of the middle temporal artery in this flap to augment the blood supply to the temporalis muscle.