Congenital adrenal hyperplasia due to 21-hydroxylase deficiency in South Africa.

BACKGROUND: Congenital adrenal hyperplasia (CAH) caused by deficiency of the 21-hydoxylase (21-OH) enzyme is the most common form of CAH worldwide. OBJECTIVE: To evaluate the prevalence of CAH due to 21-OH deficiency, and its clinical presentation and biochemical profiles in affected children. METHODS: We performed a retrospective subset analysis of 44 children with confirmed CAH. RESULTS: All the children had classic CAH. The majority (59.8%) had classic salt-wasting (CSW) CAH and 40.1% had simple virilising (SV) CAH. The median age of presentation was 8.1 years (interquartile range (IQR) 4.5 - 11) in the SV group and 2 months (IQR 2 weeks - 5 months) in the CSW group (p=0.0001). No difference in age of presentation was noted between males and females (p=0.541). The clinical presentation was significantly different between the CSW and SV groups, and between males and females in the CSW group (p<0.0001). Most of the females with 46,XX CSW CAH (66.7%) presented with disorders of sex development (DSD), while the remaining 33.3% presented with DSD and dehydration and shock. All the males with 46,XY CSW CAH presented with dehydration and shock. Overall, 37.9% (11/29) of the children were obese or overweight at presentation. Gonadotrophin-releasing hormone-dependent central precocious puberty was observed on follow-up in 29.4% (10/34) of the children at a median of 6.7 years (IQR 5 - 7.7). CONCLUSION: The diagnosis of CAH is delayed in males and females in both SV and CSW forms of the disorder, which probably contributes to under-reporting of cases and a high mortality rate.

Delayed diagnosis of anorectal malformations (ARM): causes and consequences in a resource-constrained environment.

PURPOSE: Delay in diagnosis or referral of patients with an anorectal malformation (ARM) is associated with significant morbidity and mortality. We describe the frequency and consequences of delay in recognition or referral of patients with ARM. Our study aims to determine whether the source healthcare facility affects the timing of diagnosis and to identify modifiable factors that may expedite diagnosis and referral. METHODS: Retrospective study of patients referred to a pediatric surgical service with a newly diagnosed ARM between July 2002 and December 2010. Data retrieved included patient demographics, perinatal history, time of diagnosis, clinical findings, management, and morbidity and mortality. Delay was defined as diagnosis after 24 h of birth or transfer to the tertiary referral centre more than 24 h after diagnosis. RESULTS: 273 patients (186 males, 87 females) were referred during the study period. Delays were seen in 158 (57.9%) patients with morbidity in 58 (36.7%, p < 0.001) and mortality in 9 (5.7%, p = 0.008). Delay was more frequent amongst babies born in community health centres (CHCs) than in hospitals (90.5 vs. 55.1%, p = 0.002). The median age at diagnosis was 3 days (range 2 days to 5 years). CONCLUSION: There is a need for staff education, particularly in CHCs, concerning routine neonatal examination and normal perineal anatomy. Girls, in whom a decompressive fistula is often present, are at particular risk of diagnostic delay. Delay causes increased morbidity and mortality.

Development of an automated region of interest selection method for 3D surface monitoring of head motion.

PURPOSE: To simplify the often complex and user-dependent manual region of interest (ROI) selection process for head motion monitoring, an automatic ROI selection method was developed. METHODS: The automatic ROI selection algorithm calculated the displacements and velocities of 3D surface points between a temporally correlated 3D image series and a reference image. Only facial surfaces satisfying certain spatial and temporal criteria were selected. The algorithm was tested on five healthy volunteers instructed to perform different types of facial movements for a total of 27 real-time image sets (40-120 images for each image set). RESULTS: The algorithm detected and excluded surface areas affected by different types of local facial movements that were independent of actual net head motion. Eye, eyebrow, and mandible motion were most commonly detected as being independent of head motion and were excluded from the final ROI. For 3D images taken with substantial facial or whole head motion, either most of the facial area was excluded or only small areas with random patterns were included in the final ROI. Surface image registration using iterative closest point (ICP) methods showed more stable real-time head tracking using the automatically selected ROI than manual user defined ROIs. CONCLUSIONS: The automatic selection method successfully found ROIs stable over time for tracking head motion by excluding locally varying facial motions. By automating the ROI selection process, it is feasible that the time and complexity of current ROI definition can be reduced, together with user-dependent registration errors.

SU-E-J-157: Simulation and Design of a Real-Time 6D Head Motion Compensation Platform Based on a Stewart Platform Approach.

PURPOSE: Real-time sub-millimeter head motion compensation during frameless SRS delivery has the potential to achieve the accuracy of frame-based SRS while being significantly less invasive. Previously, we demonstrated real-time 6D head motion monitoring using an optical camera, however, at the time we were limited to only 3D (x-y-z) of head motion correction due to mechanical restrictions of the head platform. In this work we investigate the feasibility of using a compact 6D robotic Stewart platform (hexapod) placed under the patient's head to perform both translational and rotational motion compensation in real-time. Benefits of a hexapod approach over a conventional serial kinematics stage include less flex, compactness, high force to weight ratio, and fast response times. METHODS: A hexapod is a parallel robotics device consisting of two platforms connected by six linear actuators oriented at particular angles. To provide accurate motion in 6D, the desired position of the top platform (head) was ascertained using inverse kinematics. MATLAB was used to simulate the six actuator positions for performing motion along x-y-z-phi -theta-psi. Prior recorded 6D human volunteer head motion data was used as an input for simulation of motion compensation. Six Firgelli L12-P linearservo actuators, together with a PCI-7344 motion controller and Labview software, were used for initial construction of a hexapod prototype. RESULTS: The necessary actuator lengths over time were computed for this data, simulating the required 6D movement of the hexapod for motion correction. Simulations on previously collected volunteer data indicate a hexapod system is capable of responding to subject head motion with corrections of precise movements, and solutions to the linear system can be computed at near real-time speeds. CONCLUSIONS: Based on simulated results, it was successfully demonstrated that a hexapod device can compensate for small patient head motions along all six degrees of freedom.

SU-E-T-409: A Comparison of 3D Optical Surface and IR Marker Tracking for Head Motion Compensated Frameless SRS.

PURPOSE: Both infrared marker and 3D facial surface tracking were performed simultaneously on both a head phantom and healthy volunteers. Accuracies of the two 6D real-time tracking systems were quantitatively assessed both spatially and temporally. The suitability of 3D facial surface tracking for providing real-time head positioning to guide a robotic head motion compensation stage was investigated. METHODS: A xyz stage was programmed to move a head phantom to approximately 200 points in 10×10×10 mm3 and 100×100×100 mm3 cubic volumes, respectively. Both 3D surface and IR marker tracking were performed simultaneously on the head phantom to allow direct comparison of spatial accuracy. Sinusoidal motion was performed along all three axis directions and recorded under the same clock cycle. Spatial and temporal accuracies on actual deformable facial surfaces were assessed by simultaneous 3D surface and IR marker tracking on human volunteers. 3D surface tracking both with and without the use of robotic head motion compensation was evaluated. RESULTS: For 10 samples at each position, the 10 mm cube had RMSE of 0.30 mm and 0.08 mm for the AlignRT and Polaris, respectively. Temporal lag of the AlignRT system was found to be approximately twice the fps time (t_{lag} ∼ 2/fps). The fps value was found to be strongly correlated with region-of-interest (ROI) surface size and could vary from 0.5 - 1.6 fps, leading to a lag time of 1 - 4 s. The Polaris output lagged behind the reference by 0.06 s in all cases. CONCLUSIONS: Both 3D surface and IR marker devices demonstrate high spatial accuracy for phantom based studies, however, a slight dimensional warping along the SI direction was observed to occur with the AlignRT. The current ROI dependent lag time of the AlignRT could also pose an issue for image guidance techniques requiring quick response times.

Urethro-ejaculatory duct reflux in children: an updated review.

AIM: Reflux of urine into the ejaculatory ducts of children may result in recurrent orchitis and sterility. Urethro-ejaculatory duct reflux (UER) is an uncommonly reported condition in children. The diagnosis of this condition can be made using a micturating cystourethrogram (MCUG) to demonstrate the reflux of contrast into any of the ejaculatory ducts. The aim of this study was to look at the incidence of UER in the broader pediatric population and review the management options. METHODS: A retrospective study was made of all MCUGs done in boys up to 13 years of age in all service departments caring for children in a teaching hospital. Those studies demonstrating UER were correlated with the hospital and departmental clinical notes. RESULTS: Over a 6 1/2 year period, 360 MCUGs were done in boys, and UER was demonstrated in 54 boys treated in seven departments. Twenty-three patients had recognized causes of UER. Eighteen patients were found to have other urological pathologies, and seven patients had neurological or complex VACTERL pathologies. The remaining six patients had no underlying pathology but presented with orchitis or torsion. Reflux into the seminal vesicles was the most frequent finding (74%), but reflux into the ductus deferens was the most debilitating. Orchitis was seen in a total of nine patients, and biopsies showed severe destruction of testicular tissue in these patients. Management of patients with recognized UER consisted of attempted correction of the underlying pathology and prolonged antibiotics. Where this failed in 6 patients, vasectomy was done in 4, and injection of a bulking gel into the verumontanum was done in 2 patients to prevent ongoing orchitis and pain. CONCLUSION: UER is more common then originally thought. All boys who present with uro-genital symptoms should have a MCUG as part of the investigative work-up and be scrutinized for UER. Management should aim at correcting any underlying anomaly and providing prolonged antibiotics, but vasectomy and the injection of a bulking agent should be considered. The indications for these newer forms of treatment are not clearly defined.

Use of MV and kV imager correlation for maintaining continuous real-time 3D internal marker tracking during beam interruptions.

The integration of onboard kV imaging together with a MV electronic portal imaging device (EPID) on linear accelerators (LINAC) can provide an easy to implement real-time 3D organ position monitoring solution for treatment delivery. Currently, real-time MV-kV tracking has only been demonstrated by simultaneous imagining by both MV and kV imaging devices. However, modalities such as step-and-shoot IMRT (SS-IMRT), which inherently contain MV beam interruptions, can lead to loss of target information necessary for 3D localization. Additionally, continuous kV imaging throughout the treatment delivery can lead to high levels of imaging dose to the patient. This work demonstrates for the first time how full 3D target tracking can be maintained even in the presence of such beam interruption, or MV/kV beam interleave, by use of a relatively simple correlation model together with MV-kV tracking. A moving correlation model was constructed using both present and prior positions of the marker in the available MV or kV image to compute the position of the marker on the interrupted imager. A commercially available radiotherapy system, equipped with both MV and kV imaging devices, was used to deliver typical SS-IMRT lung treatment plans to a 4D phantom containing internally embedded metallic markers. To simulate actual lung tumor motion, previous recorded 4D lung patient motion data were used. Lung tumor motion data of five separate patients were inputted into the 4D phantom, and typical SS-IMRT lung plans were delivered to simulate actual clinical deliveries. Application of the correlation model to SS-IMRT lung treatment deliveries was found to be an effective solution for maintaining continuous 3D tracking during 'step' beam interruptions. For deliveries involving five or more gantry angles with 50 or more fields per plan, the positional errors were found to have < or =1 mm root mean squared error (RMSE) in all three spatial directions. In addition to increasing the robustness of MV-kV tracking against beam interruption, it was also found that use of correlation can be an effective way of lowering kV dose to the patient and for increasing kV image quality by reduction of MV scatter interference.

Real-time 3D internal marker tracking during arc radiotherapy by the use of combined MV-kV imaging.

To minimize the adverse dosimetric effect caused by tumor motion, it is desirable to have real-time knowledge of the tumor position throughout the beam delivery process. A promising technique to realize the real-time image guided scheme in external beam radiation therapy is through the combined use of MV and onboard kV beam imaging. The success of this MV-kV triangulation approach for fixed-gantry radiation therapy has been demonstrated. With the increasing acceptance of modern arc radiotherapy in the clinics, a timely and clinically important question is whether the image guidance strategy can be extended to arc therapy to provide the urgently needed real-time tumor motion information. While conceptually feasible, there are a number of theoretical and practical issues specific to the arc delivery that need to be resolved before clinical implementation. The purpose of this work is to establish a robust procedure of system calibration for combined MV and kV imaging for internal marker tracking during arc delivery and to demonstrate the feasibility and accuracy of the technique. A commercially available LINAC equipped with an onboard kV imager and electronic portal imaging device (EPID) was used for the study. A custom built phantom with multiple ball bearings was used to calibrate the stereoscopic MV-kV imaging system to provide the transformation parameters from imaging pixels to 3D world coordinates. The accuracy of the fiducial tracking system was examined using a 4D motion phantom capable of moving in accordance with a pre-programmed trajectory. Overall, spatial accuracy of MV-kV fiducial tracking during the arc delivery process for normal adult breathing amplitude and period was found to be better than 1 mm. For fast motion, the results depended on the imaging frame rates. The RMS error ranged from approximately 0.5 mm for the normal adult breathing pattern to approximately 1.5 mm for more extreme cases with a low imaging frame rate of 3.4 Hz. In general, highly accurate real-time tracking of implanted markers using hybrid MV-kV imaging is achievable and the technique should be useful to improve the beam targeting accuracy of arc therapy.

Fast internal marker tracking algorithm for onboard MV and kV imaging systems.

Intrafraction organ motion can limit the advantage of highly conformal dose techniques such as intensity modulated radiation therapy (IMRT) due to target position uncertainty. To ensure high accuracy in beam targeting, real-time knowledge of the target location is highly desired throughout the beam delivery process. This knowledge can be gained through imaging of internally implanted radio-opaque markers with fluoroscopic or electronic portal imaging devices (EPID). In the case of MV based images, marker detection can be problematic due to the significantly lower contrast between different materials in comparison to their kV-based counterparts. This work presents a fully automated algorithm capable of detecting implanted metallic markers in both kV and MV images with high consistency. Using prior CT information, the algorithm predefines the volumetric search space without manual region-of-interest (ROI) selection by the user. Depending on the template selected, both spherical and cylindrical markers can be detected. Multiple markers can be simultaneously tracked without indexing confusion. Phantom studies show detection success rates of 100% for both kV and MV image data. In addition, application of the algorithm to real patient image data results in successful detection of all implanted markers for MV images. Near real-time operational speeds of approximately 10 frames/sec for the detection of five markers in a 1024 x 768 image are accomplished using an ordinary PC workstation.

Combined kV and MV imaging for real-time tracking of implanted fiducial markers.

In the presence of intrafraction organ motion, target localization uncertainty can greatly hamper the advantage of highly conformal dose techniques such as intensity modulated radiation therapy (IMRT). To minimize the adverse dosimetric effect caused by tumor motion, a real-time knowledge of the tumor position is required throughout the beam delivery process. The recent integration of onboard kV diagnostic imaging together with MV electronic portal imaging devices on linear accelerators can allow for real-time three-dimensional (3D) tumor position monitoring during a treatment delivery. The aim of this study is to demonstrate a near real-time 3D internal fiducial tracking system based on the combined use of kV and MV imaging. A commercially available radiotherapy system equipped with both kV and MV imaging systems was used in this work. A hardware video frame grabber was used to capture both kV and MV video streams simultaneously through independent video channels at 30 frames per second. The fiducial locations were extracted from the kV and MV images using a software tool. The geometric tracking capabilities of the system were evaluated using a pelvic phantom with embedded fiducials placed on a moveable stage. The maximum tracking speed of the kV/MV system is approximately 9 Hz, which is primarily limited by the frame rate of the MV imager. The geometric accuracy of the system is found to be on the order of less than 1 mm in all three spatial dimensions. The technique requires minimal hardware modification and is potentially useful for image-guided radiation therapy systems.

Examination of geometric and dosimetric accuracies of gated step-and-shoot intensity modulated radiation therapy.

Due to the complicated technical nature of gated radiation therapy, electronic and mechanical limitations may affect the precision of delivery. The purpose of this study is to investigate the geometric and dosimetric accuracies of gated step-and-shoot intensity modulated radiation treatments (SS-IMRT). Unique segmental MLC plans are designed, which allow quantitative testing of the gating process. Both ungated and gated deliveries are investigated for different dose sizes, dose rates, and gating window times using a commercial treatment system (Varian Trilogy) together with a respiratory gating system [Varian Real-Time Position Management system]. Radiographic film measurements are used to study the geometric accuracy, where it is found that with both ungated and gated SS-IMRT deliveries the MLC leaf divergence away from planned is less than or equal to the MLC specified leaf tolerance value for all leafs (leaf tolerance being settable from 0.5-5 mm). Nevertheless, due to the MLC controller design, failure to define a specific leaf tolerance value suitable to the SS-IMRT plan can lead to undesired geometric effects, such as leaf motion of up to the maximum 5 mm leaf tolerance value occurring after the beam is turned on. In this case, gating may be advantageous over the ungated case, as it allows more time for the MLC to reach the intended leaf configuration. The dosimetric precision of gated SS-IMRT is investigated using ionization chamber methods. Compared with the ungated case, it is found that gating generally leads to increased dosimetric errors due to the interruption of the "overshoot phenomena." With gating the average timing deviation for intermediate segments is found to be 27 ms, compared to 18 ms for the ungated case. For a plan delivered at 600 MU/min this would correspond to an average segment dose error of approximately 0.27 MU and approximately 0.18 MU for gated and ungated deliveries, respectively. The maximum dosimetric errors for individual intermediate segments are found to deviate by up to approximately 0.64 MU from their planned value when delivered at 600 MU/min using gating, this compares to only approximately 0.32 MU for the ungated case.

Gastrointestinal tract perforation in neonates.

Gastrointestinal tract perforation in neonates is a serious problem associated with high morbidity and mortality. Co-morbid factors, particularly prematurity and low birth weight, impact negatively on the outcome. This article highlights issues related to diagnosis and treatment with a view to improving the poor prognosis found in this condition.

Intersex conditions in children and adolescents: surgical, ethical, and legal considerations.

INTRODUCTION: Approximately one in 2000 children globally is born with an intersex condition. There is unfortunately a relative paucity of data on the choices and the surgical and psychosocial outcomes in patients who undergo genital surgery for intersex conditions and ambiguous genitalia, especially in developing countries. Specialists in these and other countries, where patient follow-up is generally poor, are faced with the daunting task of offering the appropriate medical and surgical management, in the absence of guidelines or recommendations. SURGICAL CONSIDERATIONS: A surgical procedure in these patients sometimes involves clitoral recession, reduction, vaginoplasty, and gonadectomy. The best surgical outcome is likely to be achieved with a multidisciplinary surgical team; however, the choice of surgery and appropriate timing remains controversial. Some authors have suggested delaying surgery until the child becomes competent to make his/her own decisions. LEGAL/ETHICAL CONSIDERATIONS: All procedures should conform to an ethical code of practice and be in the interest of the child. Exhaustive counseling of all parties and informed consent is of paramount importance, as is adherence to laws that protect the rights of the child as outlined in respective constitutions. RECOMMENDATIONS: Recommendations in this article, which have been put together from the combined input of three departments, are broad-based. They emphasize the need for extensive counseling, informed consent, adherence to ethical and legal norms, a multidisciplinary input and a shift away from a paternalistic approach.

True hermaphroditism in southern Africa: the clinical picture.

This is an 18-year (1985-2001) retrospective review of 85 patients with true hermaphroditism, with the aim of facilitating early recognition of this condition. Presentation of neonates and infants 6 months or younger, constituting 54% of this cohort, were different from the older children. The presentation, clinical features and investigative results of all patients diagnosed with true hermaphroditism at a single South African paediatric surgical unit were reviewed. This paper highlights the previously reported high incidence (51%) of this condition, as well as some of the unusual features of true hermaphroditism in this region. Diagnosis of true hermaphroditism requires a high index of suspicion for subtle anomalies of the genitalia. Although there were no pathognomonic clinical features, the true hermaphrodite presents as a patient of either gender with a congenital anomaly of the genitalia. The child is likely to have a normal male phallus, bifid labio-scrotal folds, a perineal hypospadias and in 53% of patients there was a palpable gonad. The method of investigation, together with the results and some of the management dilemmas associated with true hermaphroditism in a Third World population are presented.

Neonatal gastric perforation.

BACKGROUND: Gastric perforation in neonates is a catastrophe associated with high morbidity. Most are due to underlying primary pathology. OBJECTIVES: To review the management of gastric perforation in neonates in Kwa Zulu-Natal, South Africa. DESIGN: Retrospective study of consecutive complete data sets of neonates presenting with gastric perforation. SETTING: Department of Paediatric Surgery, Nelson R. Mandela School of Medicine, University of Natal, Durban, South Africa. SUBJECTS: Eight neonates treated for gastric perforation between January 1998 and April 2003. MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: There was an equal number of males and females. Median birth weight was 2.0 kg with a range of 1.4 to 3.2 kg. Five of the eight neonates were premature. Primary pathologies were associated with perforation in seven of the eight neonates. Prematurity, low birth weight and pneumonia were contributing factors to the poor outcome. Sepsis was a complication in seven of the eight neonates leading to their death (88% mortality). CONCLUSION: Active perinatal management, early treatment of primary pathologies, and protection of the stomach against distension in neonates at risk are essential in the management of neonatal gastric perforation.

Minimizing surgery in complicated intussusceptions in the Third World.

When presentation is delayed, intussusceptions may be difficult to reduce using standard enema regimens. Our endeavour to minimize the need for surgery in an environment where failed reductions are common has led to the development of an aggressive, non-operative method of reducing intussusceptions. One hundred and six patients with intussusception were reviewed with the aim of evaluating a new method of reducing intussusceptions suited to our Third World environment. In our cohort, delayed presentation was common, with 32% of patients presenting more than 48 h after the onset of the intussusception. On clinical grounds alone, 41% of patients required a primary laparotomy. Standard barium and air reductions for intussusception were rarely successful under these conditions i.e. 13% and 22%, respectively. By using an air enema under general anaesthesia in the operating theatre, the reduction rate has improved to 53%. This approach is suggested as a last attempt at reducing an intussusception prior to laparotomy following failed standard enema reduction, and as the first line of management in the attempted reduction in the patient with delayed presentation without symptoms of peritonitis.

Activated transport in the separate layers that form the nuT=1 exciton condensate.

We observe the total filling factor nuT=1 quantum Hall state in a bilayer two-dimensional electron system with virtually no tunneling. We find thermally activated transport in the balanced system with a monotonic increase of the activation energy with decreasing d/lB below 1.65. In the imbalanced system we find activated transport in each of the layers separately, yet the activation energies show a striking asymmetry around the balance point, implying a different excitation spectrum for the separate layers forming the condensed state.

Gastro-intestinal tract perforation in neonates.

BACKGROUND: Gastro-intestinal tract (GIT) perforation in neonates is a serious problem associated with high mortality due to resulting sepsis. Co-morbid factors, eg. prematurity, respiratory problems, low birth weight, and nutritional factors, negatively affect the outcome. OBJECTIVES: To review the management outcome of gastro-intestinal tract perforation in neonates in KwaZulu-Natal and identify factors that require attention for better survival of neonates with GIT perforation. DESIGN: Retrospective study of consecutive complete data sets of patients presenting with a diagnosis of GIT perforation. SETTING: Department of Paediatric Surgery, Nelson R. Mandela School of Medicine, University of Natal, Durban, South Africa. SUBJECTS: Fifty four neonates treated for gastro-intestinal tract perforation between January 1998 and January 2003. MAIN OUTCOME MEASURES: Morbidity as determined by complications and mortality. RESULTS: More males (69%) were affected than females (31%). The median birth weight was 2.3 kg and median age at presentation was four days. Eighty nine percent were referred from peripheral hospitals. Abdominal distension was the leading symptom and sign (74%). Co-morbid factors were present in 89%, with prematurity as the leading factor (52%). Necrotising enterocolitis (NEC) was the main cause of perforation (33%) and the terminal ileum was the most common site. Most (56%) were treated by excision and primary repair of perforations. Sepsis was the leading complication (44%) and major cause of death (72%). Mortality was highest (56%) in perforations due to other primary pathology followed by NEC (53%). Overall mortality was 46%. CONCLUSION: It is essential to prevent secondary perforations by early recognition and management of primary pathology. Management of pneumoperitoneum in neonates with respiratory difficulties should be included in resuscitation before transfer. Rectal temperature monitoring and herbal enemas should be strongly discouraged.

HIV-positive African children with rectal fistulae.

BACKGROUND/PURPOSE: Human immunodeficiency virus (HIV) disease is an increasingly common infection in children in sub-Sahara Africa. Rectal fistulation is one such condition with which these patients present to the paediatric surgeon. This appeared to be an exclusively female condition until 2 male patients were treated recently. METHODS: A 6-year (1996 through 2001) retrospective study found 39 children presenting with HIV-related rectal fistulae. Thirty-seven girls were seen with rectovaginal fistulae (RVF), and there is supportive documentation showing an increase in this condition throughout Southern Africa. Until now, boys have not been described with this condition. The author presents 2 boys who complete this spectrum of HIV-related acquired rectal fistulae. RESULTS: All patients were found to have rectal fistula at the dentate line. In girls it varied in size from pin-point to 5 mm diameter, tracking anteriorly into the vagina. When closure of the fistula was attempted, it broke down. The 2 boys had a large fistula, which tracked to the prostatic urethra on the right of the verumontanum. The first patient underwent a successful repair. The second patient had a "Y"-shaped fistula based at the dentate line, with the second limb passing into the bladder. The parents refused further treatment and took the child home. CONCLUSIONS: HIV disease affects increasing numbers of children. A spectrum of rectal fistulae now has been seen in both girls and boys. These acquired rectal fistulae arise at the dentate line in both genders. Girls with these fistulae are seen more commonly, presenting with RVF. The closure of a fistula has only been successful in one boy.

Rectal gastric heterotopia in infancy.

Heterotopic gastric mucosa is rare in children with most cases presenting in association with Meckel's diverticulum. The authors present a 2-year-old boy with gastric heterotopia of the anorectum, who presented with painless, intermittent rectal bleeding.