Cutting uncertain stock and vehicle routing in a sustainability forestry harvesting problem.

Sustainable forest management is concerned with the management of forests according to the principles of sustainable development. As a contribution to the field, this paper combines the Vehicle Routing Problem (VRP) (in which the vehicles are harvesters) with the Multiple Stock Size Cutting Stock Problem under uncertainty (in which the stock is logs). We present an Integer Linear Program that dynamically combines the cutting of the uncertain stock with vehicle routing, and uses it to address real-life problems. In experiments on real data from the forestry harvesting industry, we show that it outperforms a commonly used metaheuristic algorithm.

An analytics-based heuristic decomposition of a bilevel multiple-follower cutting stock problem.

This paper presents a new class of multiple-follower bilevel problems and a heuristic approach to solving them. In this new class of problems, the followers may be nonlinear, do not share constraints or variables, and are at most weakly constrained. This allows the leader variables to be partitioned among the followers. We show that current approaches for solving multiple-follower problems are unsuitable for our new class of problems and instead we propose a novel analytics-based heuristic decomposition approach. This approach uses Monte Carlo simulation and k-medoids clustering to reduce the bilevel problem to a single level, which can then be solved using integer programming techniques. The examples presented show that our approach produces better solutions and scales up better than the other approaches in the literature. Furthermore, for large problems, we combine our approach with the use of self-organising maps in place of k-medoids clustering, which significantly reduces the clustering times. Finally, we apply our approach to a real-life cutting stock problem. Here a forest harvesting problem is reformulated as a multiple-follower bilevel problem and solved using our approach.

Genetic studies in the Nigerian population implicate an MSX1 mutation in complex oral facial clefting disorders.

BACKGROUND: Orofacial clefts are the most common malformations of the head and neck, with a worldwide prevalence of 1 in 700 births. They are commonly divided into CL(P) and CP based on anatomic, genetic, and embryologic findings. A Nigerian craniofacial anomalies study (NigeriaCRAN) was set up in 2006 to investigate the role of gene-environment interaction in the origin of orofacial clefts in Nigeria. SUBJECTS AND METHODS: DNA isolated from saliva from Nigerian probands was used for genotype association studies and direct sequencing of cleft candidate genes: MSX1 , IRF6 , FOXE1, FGFR1 , FGFR2 , BMP4 , MAFB, ABCA4 , PAX7, and VAX1 , and the chromosome 8q region. RESULTS: A missense mutation A34G in MSX1 was observed in nine cases and four HapMap controls. No other apparent causative variations were identified. Deviation from Hardy Weinberg equilibrium (HWE) was observed in these cases (p = .00002). A significant difference was noted between the affected side for unilateral CL (p = .03) and bilateral clefts and between clefts on either side (p = .02). A significant gender difference was also observed for CP (p = .008). CONCLUSIONS: Replication of a mutation previously implicated in other populations suggests a role for the MSX1 A34G variant in the development of CL(P).

Pentalogy of cantrell: a report of three cases.

Pentalogy of Cantrell is a rare upper midline syndrome that may present in association with anomalies outside the torso. The pentad - the supraumbilical body wall defect, sternal defect, deficiency of the anterior diaphragm, defect of the diaphragmatic pericardium, and the intracardiac anomalies - was first described by Cantrell et al., in 1958. The defect is said to be more common in males, and survival is dependent on the cardiac malformations and on the degree of completeness of the syndrome. We report three cases of Cantrell's pentalogy managed in our unit. Two of the patients were females and one a male. All were seen at peripheral health centers before being referred to us. Age at presentation for the girls was 18 hours and 36 hours, respectively, the boy presented at the age of six weeks. All of their parents were unschooled manual workers. All patients presented with a defect in the supraumbilical body wall, bifid sternum, and a visible cardiac impulse. We were unable to do echocardiography to rule out intracardiac anomalies in the three patients. The thin membranous covering of the epigastrium in the female patients was managed conservatively. Both female patients were discharged against medical advice as requested by their parents, due to financial constraints. The male patient was lost to follow up after two clinic visits. A multidisciplinary approach to the management of this syndrome is recommended.

Day case surgery in Nigerian children: influence of social circumstances of patients.

BACKGROUND: In order to achieve good results in day surgery and avoid pitfalls, selection of appropriate procedures and patients is required with attention given to the social circumstances among other considerations. The aim of this prospective study therefore was to evaluate the influence of the social circumstances of the patients on the performance of day surgery practice in our environment. METHOD: This was a prospective study carried out between April, 2004 and December, 2004, during which time 88 children aged 15 years and below with uncomplicated inguinal hernias were treated at the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC). The parents of the patients were interviewed about their social circumstances to determine the possibility of compliance with postoperative instructions. The data generated were then analyzed. RESULTS: More than half (54.6%) of the patients were from Ile-Ife. A few came from towns varying in distances from 65 to 80 km and spent an average time of 75 to 90 minutes to reach the hospital. Majority of the patients used public vehicles as a means of transport to and from the hospital in escort of their mothers. Despite the long distances and difficult traveling conditions, the parents still preferred day case surgery and were willing to obey postoperative instructions. CONCLUSION: From the findings in this study, day case surgery in children in our environment is feasible, despite the poor social circumstances of most of them. There is, however a compelling need to raise the standard of living of the people to enable them benefit maximally from day case surgery.

Epidemiology of external birth defects in neonates in Southwestern Nigeria.

BACKGROUND: There is paucity of information on the prevalence of birth defects in Nigeria, particularly in our setting. This study determined the epidemiology of external congenital anomalies in Southwest Nigerian children. PATIENTS AND METHODS: This was a stratified, randomized study of neonates presenting with external birth defects in Ife-Ijesha in Southwestern Nigeria, from August 2003 to July 2004. The neonates were screened for obvious congenital malformations by thorough physical examination. RESULTS: A total of 624 neonates were screened, 43 (6.9%) of whom had external birth defects (prevalence: 3.7 +/- 0.8% SD). There was a slight male preponderance (M: F= 1.4: 0.9). The overall prevalence rates of external congenital and major anomalies in Ife-Ijesa are 6.9 and 3.7% respectively. A higher prevalence for major malformations, 6.3%, was also found within the minority ethnic groups in these communities compared to the native majority. Musculoskeletal abnormalities are the most common anomaly, followed by those of abnormal external genitalia and head defects. CONCLUSION: Major malformations are more common amongst the minority settlers in this study, and musculoskeletal abnormalities were the most prevalent.

Outcome of primary closure of abdominal wounds following typhoid perforation in children in Ile-Ife, Nigeria.

BACKGROUND: Abdominal wounds following surgery for typhoid perforation are classified as dirty, with an infection rate of over 40%. To date, the optimal method for closure of these wounds remains controversial. Delayed primary closure which was conventionally recommended as standard practice, is now considered to be of no value in preventing surgical site infection (SSI). This study evaluates the outcome of primary closure of this class of wounds in children in Ile-Ife, Nigeria, and advocates a multidisciplinary wound management protocol. PATIENTS AND METHODS: This is a retrospective study of children aged < 1-15 years who had had surgery for typhoid perforation in a teaching hospital in south western Nigeria, over a period of ten years. RESULTS: Thirty-two patients, 18 males and 14 females, in the ratio of 1.3:1 were managed for typhoid perforation during the ten year period. All 32 patients had primary closure of their abdominal wounds. There was primary wound healing in six (18.8%) patients, while 19 (59.4%) patients had surgical site infections. Wound dehiscence, intraabdominal abscess, and faecal fistulas were the other complications documented in the study. CONCLUSION: Abdominal wounds of typhoid perforation, though classified as being dirty, can be closed primarily with good healing outcomes. A multidisciplinary approach to wound management will reduce the incidence of wound sepsis and its associated morbidity and costs.

Determinants of mortality in neonatal intestinal obstruction in Ile Ife, Nigeria.

BACKGROUND: Neonatal intestinal obstruction (NIO) is a common cause of mortality. This study determined the causes of mortality in patients with NIO at the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile Ife. PATIENTS AND METHODS: Records of all cases of NIO managed at OAUTHC between January 1996 and December 2005 were retrospectively reviewed and the possible factors that may result in mortality were analysed. RESULTS: Sixty-three neonates with intestinal obstruction were managed, representing 24.3% of the neonatal admissions during the study period. Forty-two were males and 21 were females (M:F = 2:1). The majority (71.4%) of the patients presented within the first week of life. Anorectal malformation constituted 57.1% of the causes of NIO. Other causes included Hirschsprung's disease, duodenal atresia, intestinal malrotation with midgut volvulus and jejunal atresia. There were 18 deaths, with a mortality rate of 28.6%. Reoperation, postoperative bleeding and peroperative sepsis were significant determinants of mortality. CONCLUSION: NIO is associated with significant mortality in our centre. Repeat surgery, postoperative bleeding and sepsis were the significant factors that contributed to mortality in NIO.

Experience with transverse preputial island flap for repair of hypospadias in Ile-Ife, Nigeria.

OBJECTIVE: To review our experience with the use of transverse preputial island flap in the repair of hypospadias in the paediatric surgical unit of our University Teaching Hospital, Nigeria. PATIENTS AND METHODS: We reviewed the cases of hypospadias managed by transverse preputial island flap repair over a ten year period (1996 and 2006) in the paediatric surgical unit of our institution. Data was retrieved from the case notes and analysed. RESULTS: Fifty-one patients had hypospadias repair during the period, 22 of whom were by transverse preputial island flap repair. Hypospadisas were in penile shaft in 16 (72.7%), penoscrotal in 5 (22.7%) and perineal in 1 (4.55%). All the patients had intact prepuce at presentation and chordee was present in 18 (81.8%). The commonest complication was urethrocutaneous fistula in five patients, which closed spontaneously in three leaving 2 patients (9.1%) with persistent urethrocutaneous fistular. CONCLUSION: Transverse preputial island flap urethroplasty remains a viable option in the management of hypospadias especially when the meatal opening is proximal, with associated chordee limiting the options in the repair.

Retroperitoneal and genital lymphangioma therapeutic challenges in a developing country.

BACKGROUND: Lymphangiomas occur most commonly in the head and neck region, while other sites are rarely affected. A combination of retroperitoneal and genital lymphangioma is very rare indeed. Though congenital, it may persist into adulthood due to missed diagnosis and inadequate or total lack of treatment. MATERIALS AND METHODS: A report of a 22-year-old male student who presented with recurrent multiloculated genital, thigh, groin and retroperitneal lymphangioma. He underwent surgical excision and adjuvant sclerotherapy using ethylene-diamine tetra acetic acid. RESULTS AND CONCLUSIONS: There was an initial recurrence after surgery which responded satisfactorily to sclerotherapy. Complete surgical excision of lymphangioma may be precluded by vital structures but sclerotherapy produces satisfactory resolution. The difficulties in management with limited facilities for diagnosis and treatment are highlighted.

Evaluation of cosmetic appearance of herniotomy wound scars in African children: Comparison of tissue glue and subcuticular suturing.

AIM: To evaluate the cosmetic appearance of herniotomy wound scars closed using either the tissue glue or subcuticular suturing technique. MATERIALS AND METHODS: Prospective randomised control study; randomisation into tissue glue and suturing groups. Ethical clearance obtained. Cosmetic outcome were based on visual analogue scale by parents and Hollander wound evaluation scale by a Plastic Surgeon blinded to the wound closure method. RESULTS: Fifty one wounds were evaluated, 26 in the tissue glue group and 25 in the suturing group. Parents' evaluation using Visual Analogue scale (VAS) showed that in the suturing group, 17 parents (68%) gave a VAS of 8cm while six parents (24%) gave a score of 7cm. Two parents (8%) gave a score of 9cm. In the tissue glue group, 22 parents (84.6%) scored the scar of their children as 8 or 9cm on the VAS while four parents (15.4%) gave a score of 7cm. The median VAS was 8cm for both groups with a range of 7 to 9cm. The Chi- square test showed that the parents preferred tissue glue compared with subcuticular suturing (X2 = 7.90, P < 0.05). The Hollander Wound Evaluation Scale (HWES) used by Plastic Surgeon showed 21 herniotomy wounds (84%) had a score of 6 in the suturing group while four wounds (16%) had a score of 5. In the tissue glue group, 19 wounds (73%) had a score of 6, six wounds (23.1%) had a score of 5 and a patient (3.8%) had a score of 4. The median score is 6 for both groups. There was no statistically significant difference between both groups (X(2) = 1.481, P = 0.393). CONCLUSION: This study has shown that the cosmetic outcome of wound closure using the tissue glue technique and subcuticular suturing technique are similar.

The role of preoperative antibiotics in the prevention of wound infection after day case surgery for inguinal hernia in children in Ile Ife, Nigeria.

PURPOSE: Day case surgery for inguinal hernia had been an established practice of the Paediatric Surgery Unit, OAUTHC, Ile Ife for about two decades. In a retrospective review of the practice from the same center, a high incidence of postoperative wound infection was noted, which was attributed to the poor personal hygiene of the patients. This prospective study, therefore, was performed to evaluate the role of a single dose of preoperative antibiotic (using gentamicin) in the prevention of these wound infections after day case surgery for inguinal hernia in children. METHODS: This was a prospective study carried out over a period of 8 months from 11 April 2004 to 20 December 2004. During this period, 88 children aged from birth to 15 years were randomized into two groups of equal numbers to undergo elective inguinal herniotomy. The children in the test group received prophylactic intravenous gentamicin, 30 min before a groin crease incision was made, while those in the control group did not. All patients were subsequently followed up for 32 days for any evidence of a wound infection. RESULTS: There were 104 wounds in the ratio of 50:54 in the control and test groups, respectively. All 54 wounds of the children who received prophylactic gentamicin healed primarily and without complication. Five cases of wound infections occurred in the control group, giving an infection rate of 4.8% (P < 0.041). Staphylococcus aureus was the single pathogen isolated from the infected postherniotomy wounds and this organism was wholly sensitive to gentamicin. CONCLUSION: From the findings in this study, administration of preoperative gentamicin has a role in the prevention of wound infection after day case surgery for inguinal hernias in susceptible children. Preoperative intravenous gentamicin is therefore recommended as a prophylactic measure against wound infection after day case surgery for inguinal hernias in those children at risk of wound infection.

Day case inguinal hernia surgery in Nigerian children: prospective study.

BACKGROUND: There has been an increase in day case surgery for children worldwide, but there have been few reports of the practice (most of them being retrospective) by many of the surgical sub-specialties in the sub-region. The aim of this study was to document our experience with day case inguinal hernia surgery in a developing economy. MATERIALS AND METHODS: This was a prospective study of uncomplicated inguinal hernias treated as day case at OAUTHC between April 2004 and December 2004. Data were collected and analysed. RESULTS: Eighty-eight patients were recruited into the study and none defaulted. There were 88 patients, (M:F = 16.6:1). A majority (n = 54) of the hernias occurred on the right side, while just a few (n = 18) occurred on the left. There were 5 cases of wound infections giving an infection rate of 4.8%. In all, the morbidity following day case inguinal hernia surgery was slight and no patient required readmission into the hospital. CONCLUSION: Day case inguinal hernia surgery in children is safe and well accepted by patients and parents alike. Health institutions in which children with inguinal hernias still queue for long periods for space on the operation list need to adopt day case surgery for inguinal hernia in order to forestall the risk of their obstruction.

Posterior sagittal approach in complicated Swenson's pull-through.

CONTEXT: Swenson's pull-through is one of the standard operations for the treatment of children with Hirschsprung's disease. Complications arising from the operation are difficult to treat because of fibrosis in the pelvis. The posterior sagittal approach may be a safer alternative. AIMS: The aim of this paper is to highlight our experience with the use of the posterior sagittal trans-sphincteric approach to treat unusual complications of Swenson's pull-through. SETTINGS AND DESIGN: A retrospective study of four patients who had posterior sagittal repair of their complications of Swenson pull-through at the Obafemi Awolowo University Teaching Hospital, Ile Ife, Nigeria. MATERIALS AND METHODS: Four cases of Hirschsprung's disease that developed post-Swenson pull-through complications are presented. There were three males and one female. Their age ranged between 10 months and 15 years. The patients had rectovaginal fistula, rectourethral fistula, high trans-sphincteric fistula-in-ano and complete anastomotic disruption. RESULT: All the patients were successfully treated using the posterior sagittal approach. The approach was used twice in one patient without significant sequelae. The three patients were old enough to be assessed and had a Kelly score of 4-6 at follow-up. CONCLUSION: The posterior sagittal technique offers a safe approach to treat the complications of Swenson pull-through.

Pattern and factors affecting management outcome of spina bifida cystica in Ile-Ife, Nigeria.

BACKGROUND AND OBJECTIVE: There is paucity of data on the pattern and factors affecting the management outcome of patients with spina bifida cystica in the Ife-Ijesa zone, Nigeria. This study was designed to address this research question. METHOD: One hundred and six consecutive cases of spina bifida cystica who presented in our hospital from January 1990 to December 2004 were reviewed. We obtained information on sociodemographic factors, medical history and management as well as clinical outcome. SPSS was used to analyze the data. RESULT: Males constituted 54.7% and females 45.2% of cases. Mortality was high in those presented after the 4th week of life (p = 0.04). The malformation occurred in the lumbar and lumbosacral regions in 77.4%. Myelomeningocele was the most common type (86.8%). Hydrocephalus was recorded in 53.8% of patients. Surgical closure was done for 91.5% of the patients. About 77% of all the patients were discharged while 22.7% died. This was significantly related to age at presentation (p = 0.04) and infection before surgery (p = 0.045). Postoperative complications were more frequent in patients with ruptured lesions (p = 0.025), a larger size of defect (p = 0.028) and a lower birth weight (p = 0.006). CONCLUSION: Myelomeningocele is the most common type of spina bifida cystica in our environment. Late presentation and preoperative infection are associated with high mortality in our patients.

Successful separation of two pairs of conjoined twins in Ile Ife, Nigeria: case reports.

Conjoined twins are rare phenomena occurring in one in 1 in 50,000 live births. Successful surgical separation of conjoined twins is a major undertaking requiring careful planning by a multidisciplinary team. Reports of seperation of joined twins in developing countries like Nigeria are rare. Ten cases of conjoined twins were separated between 1936 and January 2003 (including the authors two new cases). There were five omphalopagus, two pygopagus, two heterpagus and one ishiopagus twins. Three underwent emergency separation with 83.3% mortality while seven underwent elective seperation with 64.3% survival. The overall mortality rate was 50%. Despite the absence of advanced technological resource selected group of conjoined twins can be successfully separated in a developing country like Nigeria. An improvement in facilities and availability of trained personnel in likely to be associated with improved outcome.

Experience with anorectal malformations in Ile-Ife, Nigeria.

The study was carried out to determine the characteristics and outcome of management of anorectal malformations (ARM) in Nigerian children at the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC) in Ile-Ife, Nigeria, between January 1986 and December 2002. Eighty-six children with ARM were studied, 48 males and 38 females. Only 12 (13.9%) presented to the hospital within 24 h of birth. Twenty-four (27.9%) patients had one or more associated congenital anomalies, with oesophageal atresia with tracheo-oesophageal fistula being the most common associated malformation. A low variety was identified in 26 (30.2%) cases, while 60 (69.8%) had intermediate or high lesions. Twenty-two patients with the low type of anomaly were offered primary anoplasty in the neonatal period, whereas 59 patients with intermediate or high malformations were offered a preliminary colostomy. A definitive pull-through procedure was ultimately performed in 27 of these 59 cases. Twenty-six patients (30.2%) died. Infection and severe associated malformations were responsible for most (65%) of the deaths. Early results of definitive surgery among survivors were generally good after a mean follow-up period of 13 months. Late presentation, inadequate facilities for neonatal intensive care, and paucity of specialist supportive personnel appear to have negatively influenced the outcome of treatment in our environment. Increasing awareness and availability of medical facilities and specialists are needed.

Anaesthesia for neonatal surgical emergencies in a semi-urban hospital, Nigeria.

OBJECTIVE: To establish the techniques of anaesthesia for neonatal surgical emergencies in a semi-urban hospital in Nigeria, assess their adequacy and make recommendations to improve our practice. DESIGN: Retrospective study. SETTING: Obafemi Awolowo University Teaching Hospital, Ile-lfe, Nigeria, from January 1990 to December 2000. SUBJECTS: One hundred neonates aged one to twenty eighty days. RESULTS: One hundred neonatal surgical emergencies were operated but only 76 case notes were available for review. Three hundred and fifty eight elective neonatal surgeries were done during the same period. The ASA classification were: ASA IE=10, 2E=25, 3E=28, 4E =12 and 5E=1. The mean weight was 2.66+/ 0.52 kg. Over 95% of the cases were done under general anaesthesia. Anorectal malformations and intestinal obstruction were the most common indications for surgery (64.5%). Nurse anaesthetists gave over 50% of the anaesthetics. Peri-operative adverse events such as tachycardia, respiratory distress, aspiration and hypothermia were recorded in 11.8% of the cases. Mortality was 39.2%. CONCLUSION: General anaesthesia is still the main technique of anaesthesia and mortality following surgery is still high. Efforts should be made to train appropriate personnel to provide improved care and thereby reduce morbidity and mortality.

Acute generalized peritonitis in African children: assessment of severity of illness using modified APACHE II score.

BACKGROUND: Generalized surgical acute abdomen is a significant cause of morbidity and mortality among children. Severity assessment is useful in order to prioritize treatment and reduce complications. Patients with a high severity score are often faced with high morbidity and mortality, thus, requiring more intensive treatment than those with low severity scores. The purpose of the present study was to assess the severity of the acute abdomen in paediatric patients using a modification of the acute physiological and chronic ill-health evaluation II score (APACHE II). METHODS: Children admitted and operated on for generalized acute abdomen over a period of 7 years from January 1993 to December 1999 were prospectively studied. A study proforma was drafted and demographic, clinical, preoperative, operative and postoperative data on each patient were entered. Each patient had severity of illness assessed using APACHE II parameters with minor modification to make it applicable to children. Postoperative outcome and severity of illness were compared to determine any correlation. RESULTS: There were 69 patients operated on within the period of the study. Age ranged from 3 months to 15 years, with a mean of 9.1 SD 4.3 years. Forty-two patients (61.2%) were male and 27 (39.8%) were female. Typhoid intestinal perforation accounted for 35 (50.7%) and intestinal obstruction with or without intestinal gangrene accounted for nine (13%). Modified APACHE II score ranged from 0 to 18, mean 8.5 SD 5. For survivors, the mean score was 8; for non-survivors, 13. Eight patients died (11.6%): four of 63 (6.4%) patients who scored 0-15 died; four of six (66.7%) patients who scored 16-18 (P < 00.05) died. A modified APACHE II score greater than 15 was associated with a significantly greater mortality. The data for postoperative morbidity and hospital stay were not conclusive. CONCLUSION: Although the APACHE II score was designed for adults, a modification can be suitably applied to predict mortality in children with generalized peritonitis. There will be a need to apply this to large number of patients in order to validate our finding.

Surgical audit in the developing countries.

Audit assures provision of good quality health service at affordable cost. To be complete therefore, surgical practice in the young developing countries, as elsewhere, must incorporate auditing. Peculiarities of the developing countries and insufficient understanding of auditing may be, however, responsible for its been little practised. This article, therefore, reviews the objectives, the commonly evaluated aspects, and the method of audit, and includes a simple model of audit cycle. It is hoped that it will kindle the idea of regular practice of quality assurance by surgeons working in the young developing nations and engender a sustainable interest.