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).

Ten-year experience with the swenson procedure in Nigerian children with hirschsprung's disease

Background: Hirschsprung's disease (HD) is a common cause of intestinal obstruction in children. Definitive treatments consist of excision of the aganglionic segment and anastomosing the normal colon to the anal remnant. The outcome of this approach in Nigerian children is not known. The aim of this study was to analyze the short to mid-term outcome of children who have undergone the Swenson Procedure (SPT) as a treatment of HD over a period of 10 years. Patients and Methods: The clinical data of biopsy-proven cases of HD managed at the Obafemi Awolowo University Teaching Hospital; Ile-Ife; Nigeria; between 1998 and 2007 were reviewed. Results: There were 33 children 28 were males and five were females (M 5.6: F = 1). The median age at presentation was eight months (range three days to 11 years). Eighteen (54.5) patients had primary pull-through without colostomy while 15 (45.5) patients had a two-staged operation. The operation was carried out at a median age of 14 months with a range of seven weeks to 11 years; four months. Twenty-one (64) of the patients were older than one year at the time of surgery. The level of aganglionosis was in the recto-sigmoid area in 30 (91) patients. The commonest post-SPT complication was intestinal obstruction from adhesions. Bowel opening varied from once daily to eight times daily; median thrice daily. Conclusion: The Swenson's Procedure is an effective procedure in the treatment of HD in children in Ile Ife; Nigeria

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.

Circumcision Mishaps: A Continuing Challenge In The Developing Countries

Objective: Circumcision has been described as the most commonly performed surgical operation in the boys and is probably the oldest surgical procedure in man. This prospective study was aimed at establishing the pattern; treatment outcome and cost of major complications of neonatal circumcision seen in a tertiary center in Nigeria. Methods: Consecutive cases of complications of circumcision presenting at the Paediatric Outpatient Department in a tertiary centre in Nigeria were prospectively studied over a period of 3 and half years from July 2003 to December 2006. Information regarding the age of the patient; time of circumcision; the surgeon; place of circumcision was recorded as well as the type of mishap; outcome and cost of management were noted. Results: Forty five patients with major complications of circumcision representing 6.2of the patients. Their age at presentation ranged between 2 weeks to 10 years (Median = 3months). All the patients were circumcised during the neonatal period. The commonest complication reported is urethro-cutaneous fistula in 25 (56); Meatal Stenosis in 4(8.9); Severe bleeding in 4(8.9); Epidermoid cyst in 3 (6.7); and 2 (4.4) cases each of Buried penis; penile amputation; penile degloving with glans amputation; glanular adhesions and redundant prepuce respectively. The cost of treatment for the repairs varies from 4500 -35;000NGN (40-305 Dollars) Conclusion: The prevalence of complications of circumcision is high in our environment

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 24.3of 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 57.1of 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

Epidemiology of external birth defects in neonates in South Western 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 [+ or -] 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

Challenges of Surgical Repair of Hypospadias in Ile-Ife; Nigeria

Objective: To document the presentation; outcome and challenges of management of hypospadias in a resource-limited setting. Patients and Methods: For this retrospective study we analyzed the files of all patients with hypospadias managed at the Obafemi Awolowo University Teaching Hospital; Ile-Ife; Nigeria between 1996 and 2006. The parameters studied were the patients' bio-data; clinical presentation; treatment and outcome. Results: During the 10-year period under review 51 cases of hypospadias were managed. The majority of the patients (n=39; 76.5) presented within the first year of life with a mean age at presentation of 1 year and 8 months; though most of the repairs were done in the 2nd; 3rd and 4th years of life. Of the 51 patients 46 (90.2) came from rural and semi-urban areas and 18 (35.3) had been circumcised before presentation. Surgical repair consisted of preputial island flap in 22 patients (43.1) followed by a peri-meatal based flap (Mathieu procedure) in 16 patients (31.4). The MAGPI procedure was used in 5 patients (9.8) and the Snodgrass procedure in 1 (2). Staged repair was necessary in 7 patients (13.7). Post-operative complications were encountered in 15 patients with urethrocutaneous fistula being the commonest one (11 patients; 21.6). Conclusion: Our results show that hypospadias can be successfully managed in a low- resource setting

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

Typhoid Perforation: Determinants of Outcome in Children in Ile-Ife; Nigeria

Background: Ileal perforation can be a fatal complication of typhoid fever in children as its clinical presentation is often atypical. The risk of death from intestinal perforation in typhoid fever is more than four times when compared with patients without perforation. A high index of suspicion therefore; and early intervention are mandatory to reduce morbidities and deaths due to this disease in children. Aim: To highlight the factors that adversely influence treatment outcome following typhoid ileal perforation in a paediatric population and how they could be modified to reduce morbidity and mortality. Methods: This was a retrospective study whereby medical records of children aged 1 to 15 years with typhoid fever admitted to OAUTHC; Ile-Ife; over a 10-year period; 1994-2004. Results: A total of 38 patients; 20 males and 18 females in the ratio 1.1:1; were managed for typhoid perforation during the 10-year study period. Twenty-nine patients (76.3) survived while 9 (23.7) died. Of the many factors evaluated; only the duration of time before operation was found to significantly influence treatment outcome adversely (P=0.009); while large single or large multiple perforations (P=0.256); severe peritoneal contamination (P=0.291) and extensive surgery (P=0.089) did not. Conclusion: Typhoid ileal perforation has a poor treatment outcome in children in Ile-Ife; Nigeria. The duration of time before operation was the single most important factor that adversely affected treatment outcome. Therefore; swift preoperative resuscitation and early surgical intervention will enhance overall outcome irrespective of the number of perforations; severity of faecal contamination and extent of surgery

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.