Dirk von Delft - Academia.edu (original) (raw)

Papers by Dirk von Delft

Pediatric Surgery International, Dec 17, 2022

Vascular Medicine, May 28, 2010

Synthetic and to a lesser extent vein graft failure is still a major problem in the treatment of ... more Synthetic and to a lesser extent vein graft failure is still a major problem in the treatment of peripheral arterial disease, with neointimal hyperplasia being the main cause for graft occlusion in the medium and long term. This review aims to establish the current status of external stents or sheaths in the prevention of intimal hyperplasia in small diameter (< 6 mm) vein grafts.

Bangladesh journal of endosurgery, 2013

Background: Foreign body aspiration is a common cause of pulmonary complications and accidental d... more Background: Foreign body aspiration is a common cause of pulmonary complications and accidental death in children. A high index of suspicion and an early bronchoscopy are essential for the removal of an aspirated foreign body to prevent morbidity and mortality. Methods: This is a retrospective audit of the cases of aspirated foreign bodies in children up to 15 years of age managed in our unit over a 16-year period from 1st February 1995 to 31st January 2011. Results: There were 37 children with the diagnosis of foreign body aspiration during this period. Twenty-seven of these children resided between 50 and 200 km from our hospital. The age ranged from 14 months to 14 years. Twenty-one of these patients presented with an acute onset of respiratory distress without a history of choking. A radioopaque foreign body was visible only in 13 children. In 14 patients, the chest radiograph was normal. The foreign bodies were removed by rigid bronchoscopy. In 29 out of the 37 children the foreign body was non-food product. One patient had a tension pneumothorax and surgical emphysema which settled with a chest drain. Conclusion: An early bronchoscopy, done by a competent surgeon with a rigid bronchoscope deals effectively with the problem of aspirated foreign body, with minimum morbidity. The ability to safely remove an aspirated foreign body is an essential skill to be acquired as part of the training of paediatric surgeons in the developing world.

European Heart Journal - Case Reports, Jul 6, 2019

Background Paediatric penetrating cardiac injury is extremely rare, precluding published manageme... more Background Paediatric penetrating cardiac injury is extremely rare, precluding published management guidelines, therefore warranting a case-by-case approach with learning points gleaned from each case.

Hirschsprung's Disease and Allied Disorders

Intestinal motility is a highly coordinated process and depends on smooth muscle contractility, t... more Intestinal motility is a highly coordinated process and depends on smooth muscle contractility, the pacemaker activity evoked by the intestinal cells of Cajal, and the summation of the effects of the enteric and autonomic nervous systems on gut function. Crippling gastrointestinal dysfunction can result from a variety of abnormalities, involving these elements individually or in combination.

Pediatric Surgery International

South African journal of surgery. Suid-Afrikaanse tydskrif vir chirurgie, 2011

African degenerative leiomyopathy (ADL) is a rare incurable disorder seen in African children, pr... more African degenerative leiomyopathy (ADL) is a rare incurable disorder seen in African children, predominantly in southern and south-eastern Africa. ADL presents as chronic intestinal pseudo-obstruction. Management is traditionally conservative, with surgery restricted to the management of complications. We have placed Malone antegrade continence enema (MACE) stomas in the grossly dilated colon to vent accumulated gas and administer antegrade bowel enemas. This is done mainly for relief of gaseous distension and constipation in an attempt to provide symptomatic relief and improve quality of life. In this article, we present our preliminary results of laparoscopically assisted technique to insert a Mic-Key gastrostomy device as a 'button colostomy' in 8 patients over the past 6½ years.

The Lancet, 2021

Background Congenital anomalies are the fifth leading cause of mortality in children younger than... more Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58•0%) were male. Median gestational age at birth was 38 weeks (IQR 36-39) and median bodyweight at presentation was 2•8 kg (2•3-3•3). Mortality among all patients was 37 (39•8%) of 93 in low-income countries, 583 (20•4%) of 2860 in middle-income countries, and 50 (5•6%) of 896 in high-income countries (p<0•0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90•0%] of ten in lowincome countries, 97 [31•9%] of 304 in middle-income countries, and two [1•4%] of 139 in high-income countries; p≤0•0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2•78 [95% CI 1•88-4•11], p<0•0001; middle-income vs high-income countries, 2•11 [1•59-2•79], p<0•0001), sepsis at presentation (1•20 [1•04-1•40], p=0•016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4-5 vs ASA 1-2, 1•82 [1•40-2•35], p<0•0001; ASA 3 vs ASA 1-2, 1•58, [1•30-1•92], p<0•0001]), surgical safety checklist not used (1•39 [1•02-1•90], p=0•035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1•96, [1•41-2•71], p=0•0001; parenteral nutrition 1•35, [1•05-1•74], p=0•018). Administration of parenteral nutrition (0•61, [0•47-0•79], p=0•0002) and use of a peripherally inserted central catheter (0•65 [0•50-0•86], p=0•0024) or percutaneous central line (0•69 [0•48-1•00], p=0•049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030. Funding Wellcome Trust.

Pediatric Surgery International, 2015

Aim To develop and validate a scoring system for a training assessment tool using a box trainer w... more Aim To develop and validate a scoring system for a training assessment tool using a box trainer which can objectively demonstrate progression in laparoscopic skills. Method 170 assessments were performed over a 5-year period by doctors working in a busy paediatric surgical department. Each participant was scored based on experience and then undertook six laparoscopic tasks in a box trainer in a dry skills lab. The quicker and more accurate the performance, the lower the score. Validity and reliability tests were applied. Results Pearson correlation coefficient demonstrated that more experienced surgeons performed better than novices with an r of-0.63 (p \ 0.001). The mean assessment scores improved (reduced) with increasing experience score [4140 (0-20), 2696 (21-40), 1969 ([40) p \ 0.001]. Improvement in score was seen at all experience levels with greatest improvement seen in the less experienced (2315, 1820, 1571 p \ 0.001). Cronbach's alpha was 0.70 and the intraclass correlation coefficient for test-retest reliability was 0.81. Conclusion Construct validity with adequate reliability has been demonstrated for this simple training tool and scoring system. All experience levels demonstrated improvement in their laparoscopic skills by simulation training in a laparoscopic box trainer.

Veterinary parasitology, Jan 23, 2013

Cystic echinococcosis is a serious and neglected parasitic zoonosis that is regarded as an emergi... more Cystic echinococcosis is a serious and neglected parasitic zoonosis that is regarded as an emerging disease world-wide. Effective control of the disease is based on understanding the variability of Echinococcus granulosus (sensu lato), as genotypic characteristics may influence lifecycle patterns, development rate, and transmission. No molecular epidemiological research has previously been conducted to shed light on genotypes responsible for the disease in South Africa. To identify strains circulating in the country, parasite material was collected from patients between August 2010 and September 2012 and analyzed by PCR/RFLP methods. A total of 32 samples was characterized as E. granulosus sensu stricto (G1-G3) (81%), E. canadensis (G6/7) (16%) and E. ortleppi (G5) (3%). Furthermore, two co-amplifying G6/7 genotypes were confirmed as G7 by sequencing. This is the first report on genotyping of Echinococcus species in South Africa, and, to the best of our knowledge, the first report o...

Vascular Medicine, 2010

Synthetic and to a lesser extent vein graft failure is still a major problem in the treatment of ... more Synthetic and to a lesser extent vein graft failure is still a major problem in the treatment of peripheral arterial disease, with neointimal hyperplasia being the main cause for graft occlusion in the medium and long term. This review aims to establish the current status of external stents or sheaths in the prevention of intimal hyperplasia in small diameter (< 6 mm) vein grafts.

Annals of Emergency Medicine, 1985

European Heart Journal - Case Reports, 2019

Background Paediatric penetrating cardiac injury is extremely rare, precluding published manageme... more Background Paediatric penetrating cardiac injury is extremely rare, precluding published management guidelines, therefore warranting a case-by-case approach with learning points gleaned from each case. Case summary A 7-year-old boy presented to a rural hospital with a stab wound to the chest by a Withaak (Vachellia tortilis) thorn. The patient was haemodynamically stable on presentation, but a 2 cm subcutaneous, pulsatile mass was present at the cardiac apex. Echocardiography revealed a foreign body penetrating from the apex into the heart, with evidence for a fistula between a cardiac chamber and the pulsatile mass. Angiography confirmed the existence of the fistula between the right ventricle (RV) and the pulsatile mass. A controlled extraction under general anaesthaesia via median sternotomy was performed in-theatre, with blood products and cardiac bypass on standby. The patient recovered without complications and was discharged after 4 days. Discussion Our case illustrates the l...

Pediatric Surgery International, 2020

Central venous access is frequently essential for the management of many acute and chronic condit... more Central venous access is frequently essential for the management of many acute and chronic conditions in children. Millions of central venous access devices (CVADs) are placed each year. In this review article, we discuss the indications for longterm vascular access, the types of devices available, the state of the art of central venous cannulation and device placement, and the complications of long-term central venous access. We pay a special attention to the challenges of, and options for long-term central venous access, also those in developing countries, with limited financial, human, and material resources.

Pediatric Surgery International, Dec 17, 2022

Vascular Medicine, May 28, 2010

Synthetic and to a lesser extent vein graft failure is still a major problem in the treatment of ... more Synthetic and to a lesser extent vein graft failure is still a major problem in the treatment of peripheral arterial disease, with neointimal hyperplasia being the main cause for graft occlusion in the medium and long term. This review aims to establish the current status of external stents or sheaths in the prevention of intimal hyperplasia in small diameter (< 6 mm) vein grafts.

Bangladesh journal of endosurgery, 2013

Background: Foreign body aspiration is a common cause of pulmonary complications and accidental d... more Background: Foreign body aspiration is a common cause of pulmonary complications and accidental death in children. A high index of suspicion and an early bronchoscopy are essential for the removal of an aspirated foreign body to prevent morbidity and mortality. Methods: This is a retrospective audit of the cases of aspirated foreign bodies in children up to 15 years of age managed in our unit over a 16-year period from 1st February 1995 to 31st January 2011. Results: There were 37 children with the diagnosis of foreign body aspiration during this period. Twenty-seven of these children resided between 50 and 200 km from our hospital. The age ranged from 14 months to 14 years. Twenty-one of these patients presented with an acute onset of respiratory distress without a history of choking. A radioopaque foreign body was visible only in 13 children. In 14 patients, the chest radiograph was normal. The foreign bodies were removed by rigid bronchoscopy. In 29 out of the 37 children the foreign body was non-food product. One patient had a tension pneumothorax and surgical emphysema which settled with a chest drain. Conclusion: An early bronchoscopy, done by a competent surgeon with a rigid bronchoscope deals effectively with the problem of aspirated foreign body, with minimum morbidity. The ability to safely remove an aspirated foreign body is an essential skill to be acquired as part of the training of paediatric surgeons in the developing world.

European Heart Journal - Case Reports, Jul 6, 2019

Background Paediatric penetrating cardiac injury is extremely rare, precluding published manageme... more Background Paediatric penetrating cardiac injury is extremely rare, precluding published management guidelines, therefore warranting a case-by-case approach with learning points gleaned from each case.

Hirschsprung's Disease and Allied Disorders

Intestinal motility is a highly coordinated process and depends on smooth muscle contractility, t... more Intestinal motility is a highly coordinated process and depends on smooth muscle contractility, the pacemaker activity evoked by the intestinal cells of Cajal, and the summation of the effects of the enteric and autonomic nervous systems on gut function. Crippling gastrointestinal dysfunction can result from a variety of abnormalities, involving these elements individually or in combination.

Pediatric Surgery International

South African journal of surgery. Suid-Afrikaanse tydskrif vir chirurgie, 2011

African degenerative leiomyopathy (ADL) is a rare incurable disorder seen in African children, pr... more African degenerative leiomyopathy (ADL) is a rare incurable disorder seen in African children, predominantly in southern and south-eastern Africa. ADL presents as chronic intestinal pseudo-obstruction. Management is traditionally conservative, with surgery restricted to the management of complications. We have placed Malone antegrade continence enema (MACE) stomas in the grossly dilated colon to vent accumulated gas and administer antegrade bowel enemas. This is done mainly for relief of gaseous distension and constipation in an attempt to provide symptomatic relief and improve quality of life. In this article, we present our preliminary results of laparoscopically assisted technique to insert a Mic-Key gastrostomy device as a 'button colostomy' in 8 patients over the past 6½ years.

The Lancet, 2021

Background Congenital anomalies are the fifth leading cause of mortality in children younger than... more Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58•0%) were male. Median gestational age at birth was 38 weeks (IQR 36-39) and median bodyweight at presentation was 2•8 kg (2•3-3•3). Mortality among all patients was 37 (39•8%) of 93 in low-income countries, 583 (20•4%) of 2860 in middle-income countries, and 50 (5•6%) of 896 in high-income countries (p<0•0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90•0%] of ten in lowincome countries, 97 [31•9%] of 304 in middle-income countries, and two [1•4%] of 139 in high-income countries; p≤0•0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2•78 [95% CI 1•88-4•11], p<0•0001; middle-income vs high-income countries, 2•11 [1•59-2•79], p<0•0001), sepsis at presentation (1•20 [1•04-1•40], p=0•016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4-5 vs ASA 1-2, 1•82 [1•40-2•35], p<0•0001; ASA 3 vs ASA 1-2, 1•58, [1•30-1•92], p<0•0001]), surgical safety checklist not used (1•39 [1•02-1•90], p=0•035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1•96, [1•41-2•71], p=0•0001; parenteral nutrition 1•35, [1•05-1•74], p=0•018). Administration of parenteral nutrition (0•61, [0•47-0•79], p=0•0002) and use of a peripherally inserted central catheter (0•65 [0•50-0•86], p=0•0024) or percutaneous central line (0•69 [0•48-1•00], p=0•049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030. Funding Wellcome Trust.

Pediatric Surgery International, 2015

Aim To develop and validate a scoring system for a training assessment tool using a box trainer w... more Aim To develop and validate a scoring system for a training assessment tool using a box trainer which can objectively demonstrate progression in laparoscopic skills. Method 170 assessments were performed over a 5-year period by doctors working in a busy paediatric surgical department. Each participant was scored based on experience and then undertook six laparoscopic tasks in a box trainer in a dry skills lab. The quicker and more accurate the performance, the lower the score. Validity and reliability tests were applied. Results Pearson correlation coefficient demonstrated that more experienced surgeons performed better than novices with an r of-0.63 (p \ 0.001). The mean assessment scores improved (reduced) with increasing experience score [4140 (0-20), 2696 (21-40), 1969 ([40) p \ 0.001]. Improvement in score was seen at all experience levels with greatest improvement seen in the less experienced (2315, 1820, 1571 p \ 0.001). Cronbach's alpha was 0.70 and the intraclass correlation coefficient for test-retest reliability was 0.81. Conclusion Construct validity with adequate reliability has been demonstrated for this simple training tool and scoring system. All experience levels demonstrated improvement in their laparoscopic skills by simulation training in a laparoscopic box trainer.

Veterinary parasitology, Jan 23, 2013

Cystic echinococcosis is a serious and neglected parasitic zoonosis that is regarded as an emergi... more Cystic echinococcosis is a serious and neglected parasitic zoonosis that is regarded as an emerging disease world-wide. Effective control of the disease is based on understanding the variability of Echinococcus granulosus (sensu lato), as genotypic characteristics may influence lifecycle patterns, development rate, and transmission. No molecular epidemiological research has previously been conducted to shed light on genotypes responsible for the disease in South Africa. To identify strains circulating in the country, parasite material was collected from patients between August 2010 and September 2012 and analyzed by PCR/RFLP methods. A total of 32 samples was characterized as E. granulosus sensu stricto (G1-G3) (81%), E. canadensis (G6/7) (16%) and E. ortleppi (G5) (3%). Furthermore, two co-amplifying G6/7 genotypes were confirmed as G7 by sequencing. This is the first report on genotyping of Echinococcus species in South Africa, and, to the best of our knowledge, the first report o...

Vascular Medicine, 2010

Synthetic and to a lesser extent vein graft failure is still a major problem in the treatment of ... more Synthetic and to a lesser extent vein graft failure is still a major problem in the treatment of peripheral arterial disease, with neointimal hyperplasia being the main cause for graft occlusion in the medium and long term. This review aims to establish the current status of external stents or sheaths in the prevention of intimal hyperplasia in small diameter (< 6 mm) vein grafts.

Annals of Emergency Medicine, 1985

European Heart Journal - Case Reports, 2019

Background Paediatric penetrating cardiac injury is extremely rare, precluding published manageme... more Background Paediatric penetrating cardiac injury is extremely rare, precluding published management guidelines, therefore warranting a case-by-case approach with learning points gleaned from each case. Case summary A 7-year-old boy presented to a rural hospital with a stab wound to the chest by a Withaak (Vachellia tortilis) thorn. The patient was haemodynamically stable on presentation, but a 2 cm subcutaneous, pulsatile mass was present at the cardiac apex. Echocardiography revealed a foreign body penetrating from the apex into the heart, with evidence for a fistula between a cardiac chamber and the pulsatile mass. Angiography confirmed the existence of the fistula between the right ventricle (RV) and the pulsatile mass. A controlled extraction under general anaesthaesia via median sternotomy was performed in-theatre, with blood products and cardiac bypass on standby. The patient recovered without complications and was discharged after 4 days. Discussion Our case illustrates the l...

Pediatric Surgery International, 2020

Central venous access is frequently essential for the management of many acute and chronic condit... more Central venous access is frequently essential for the management of many acute and chronic conditions in children. Millions of central venous access devices (CVADs) are placed each year. In this review article, we discuss the indications for longterm vascular access, the types of devices available, the state of the art of central venous cannulation and device placement, and the complications of long-term central venous access. We pay a special attention to the challenges of, and options for long-term central venous access, also those in developing countries, with limited financial, human, and material resources.