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Dive into the research topics where Mandela Thyoka is active.

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Featured researches published by Mandela Thyoka.


Annals of Surgery | 2013

Hypercapnia and Acidosis During Open and Thoracoscopic Repair of Congenital Diaphragmatic Hernia and Esophageal Atresia Results of a Pilot Randomized Controlled Trial

Mark Bishay; Luca Giacomello; Giuseppe Retrosi; Mandela Thyoka; Massimo Garriboli; Joe Brierley; L Harding; Stephen Scuplak; Kate Cross; Joe Curry; Edward M. Kiely; P De Coppi; Simon Eaton; Agostino Pierro

Objective: We aimed to evaluate the effect of thoracoscopy in neonates on intraoperative arterial blood gases, compared with open surgery. Background: Congenital diaphragmatic hernia (CDH) and esophageal atresia with tracheoesophageal fistula (EA/TEF) can be repaired thoracoscopically, but this may cause hypercapnia and acidosis, which are potentially harmful. Methods: This was a pilot randomized controlled trial. The target number of 20 neonates (weight > 1.6 kg) were randomized to either open (5 CDH, 5 EA/TEF) or thoracoscopic (5 CDH, 5 EA/TEF) repair. Arterial blood gases were measured every 30 minutes intraoperatively, and compared by multilevel modeling, presented as mean and difference (95% confidence interval) from these predictions. Results: Overall, the intraoperative PaCO2 was 61 mm Hg in open and 83 mm Hg [difference 22 mm Hg (2 to 42); P = 0.036] in thoracoscopy and the pH was 7.24 in open and 7.13 [difference −0.11 (−0.20 to −0.01); P = 0.025] in thoracoscopy. The duration of hypercapnia and acidosis was longer in thoracoscopy compared with that in open. For patients with CDH, thoracoscopy was associated with a significant increase in intraoperative hypercapnia [open 68 mm Hg; thoracoscopy 96 mm Hg; difference 28 mm Hg (8 to 48); P = 0.008] and severe acidosis [open 7.21; thoracoscopy 7.08; difference −0.13 (−0.24 to −0.02); P = 0.018]. No significant difference in PaCO2, pH, or PaO2 was observed in patients undergoing thoracoscopic repair of EA/TEF. Conclusions: This pilot randomized controlled trial shows that thoracoscopic repair of CDH is associated with prolonged and severe intraoperative hypercapnia and acidosis, compared with open surgery. These findings do not support the use of thoracoscopy with CO2 insufflation and conventional ventilation for the repair of CDH, calling into question the safety of this practice. The effect of thoracoscopy on blood gases during repair of EA/TEF in neonates requires further evaluation. (ClinicalTrials.gov Identifier: NCT01467245)


Journal of Pediatric Surgery | 2011

Decreased cerebral oxygen saturation during thoracoscopic repair of congenital diaphragmatic hernia and esophageal atresia in infants

Mark Bishay; Luca Giacomello; Giuseppe Retrosi; Mandela Thyoka; Shireen A. Nah; Merrill McHoney; Paolo De Coppi; Joe Brierley; Stephen Scuplak; Edward M. Kiely; Joe Curry; David P. Drake; Kate Cross; Simon Eaton; Agostino Pierro

BACKGROUND/PURPOSE Congenital diaphragmatic hernia (CDH) and esophageal atresia with tracheoesophageal fistula (EA/TOF) can be repaired thoracoscopically, but this may cause hypercapnia, acidosis, and reduced cerebral oxygenation. We evaluated the effect of thoracoscopy in infants on cerebral oxygen saturation (cSO(2)), arterial blood gases, and carbon dioxide (CO(2)) absorption. METHODS Eight infants underwent thoracoscopy (6 CDH and 2 EA/TOF). Serial arterial blood gases were taken. Regional cSO(2) was measured using near-infrared spectroscopy. Absorption of insufflated CO(2) was calculated from exhaled (13)CO(2)/(12)CO(2) ratio measured by mass spectrometry. RESULTS CO(2) absorption increased during thoracoscopy with a maximum 29% ± 6% of exhaled CO(2) originating from the pneumothorax. Paco(2) increased from 9.4 ± 1.3 kPa at the start to 12.4 ± 1.0 intraoperatively and then decreased to 7.6 ± 1.2 kPa at end of operation. Arterial pH decreased from 7.19 ± 0.04 at the start to 7.05 ± 0.04 intraoperatively and then recovered to 7.28 ± 0.06 at end of operation. Cerebral hemoglobin oxygen saturation decreased from 87% ± 4% at the start to 75% ± 5% at end of operation. This had not recovered by 12 (74% ± 4%) or 24 hours (73% ± 3%) postoperatively. CONCLUSIONS This preliminary study suggests that thoracoscopic repair of CDH and EA/TOF may be associated with acidosis and decreased cSO(2). The effects of these phenomena on future brain development are unknown.


European Journal of Pediatric Surgery | 2012

Advanced necrotizing enterocolitis part 1: mortality.

Mandela Thyoka; P De Coppi; Simon Eaton; K. Khoo; Nigel J. Hall; Joe Curry; Edward M. Kiely; David P. Drake; Kate Cross; Agostino Pierro

AIM OF THE STUDY The aim of this study was to investigate the factors associated with mortality in infants referred for the surgical treatment of advanced necrotizing enterocolitis (NEC). METHODS Retrospective review of all infants with confirmed (Bell stage II or III) NEC treated in our unit during the past 8 years (January 2002 to December 2010). Data for survivors and nonsurvivors were compared using Mann-Whitney test and Fishers exact test and are reported as median (range). RESULTS Of the 205 infants with NEC, 35 (17%) were medically managed; 170 (83%) had surgery; 66 (32%) infants died; all had received surgery. Survivors and nonsurvivors were comparable for gestational age, birth weight, and gender distribution. Overall mortality was 32%, the highest mortality was in infants with pan-intestinal disease (86%) but remained significant in those with less severe disease (multifocal 39%; focal disease 21%). The commonest cause of mortality was multiple organ dysfunction syndrome and nearly half of the nonsurvivors had care withdrawn. CONCLUSION Despite improvement in neonatal care, overall mortality (32%) for advanced NEC has not changed in 10 years. Mortality is significant even with minimal bowel involvement.


European Journal of Pediatric Surgery | 2012

Advanced necrotizing enterocolitis part 2: recurrence of necrotizing enterocolitis.

Mandela Thyoka; Simon Eaton; Nigel J. Hall; David P. Drake; Edward M. Kiely; Joe Curry; Kate Cross; P De Coppi; Agostino Pierro

AIM OF THE STUDY The aim of this study was to report incidence and clinical outcomes of recurrent necrotizing enterocolitis (NEC). METHODS Review of infants treated for recurrent episode(s) of NEC at a tertiary Neonatal Surgical Intensive Care Unit over 8 years (January 2002 to February 2011). Demographic, clinical, radiological, and operative data were analyzed and compared using Mann-Whitney or Fishers exact tests. Data are reported as median (range). RESULTS A total of 212 consecutive infants were referred for surgical evaluation and treatment of NEC (Bell stage II or III). Of these patients, 22 (10%) had suspected recurrent NEC: in 11 of these the primary episode was Bell stage I successfully treated before coming to our institution (suspected recurrent NEC); in the remaining 11, the primary episode was confirmed (Bell stage II or III) NEC successfully treated in our hospital. Birth weight, gestational age at birth, corrected gestational age, weight on admission, gender, need for surgery, stricture, and mortality rates were similar between infants with recurrent NEC and those with a single episode. Long-term parenteral nutrition (PN) dependency (>28 days) was significantly more common following recurrent NEC compared with a single episode. Among the infants with recurrent NEC, medical therapy alone was not successful in the majority (82%) of cases during the first episode and all required surgery during the recurrent episode. CONCLUSION Infants (10%) referred for surgical treatment of NEC develop recurrence of the disease. Surprisingly, these infants have similar mortality and stricture rates to those with a single episode. However, the incidence of long-term PN dependency was significantly increased in those with recurrent episodes of NEC.


Radiology | 2014

Fluoroscopic Balloon Dilation of Esophageal Atresia Anastomotic Strictures in Children and Young Adults: Single-Center Study of 103 Consecutive Patients from 1999 to 2011

Mandela Thyoka; Alex M. Barnacle; Samantha Chippington; Simon Eaton; David P. Drake; Kate Cross; Paolo De Coppi; Edward M. Kiely; Agostino Pierro; Joe Curry; Derek J. Roebuck

PURPOSE To determine whether fluoroscopic balloon dilation (FBD) is a safe and effective method of treating esophageal anastomotic stricture after surgical repair in an unselected patient population. MATERIALS AND METHODS With ethics committee approval, records for 103 consecutive patients who underwent FBD with our interventional radiology service (1999-2011) were reviewed retrospectively. Patients underwent diagnostic contrast material-enhanced study prior to the first dilation. Dilations were performed by using general anesthesia. Outcomes were number and/or frequency of dilations, clinical effectiveness and response to dilations, esophageal perforation, requirement for surgery, and mortality. Data were expressed as mean ± standard deviation (with range). Comparisons were conducted by using the Fisher exact test and log-rank test. The significance level was set at P < .05. RESULTS One hundred three patients (61 male patients, 59%) underwent 378 FBD sessions (median, two dilations per patient; range, 1-40 dilations). The median age at first FBD was 2.2 years (range, 0.1-19.5 years). The balloon catheter diameters ranged from 4 to 20 mm. FBD was successful in 93 patients (90%): 44 (47%) after single dilation and 49 (53%) after multiple dilations. There was no difference in the proportion of patients who required one dilation and were younger than 1 year versus those who were 1 year of age and older (P > .99; odds ratio, 1.07 [range, 0.43-2.66]). Ten patients (10%) required further procedures: Three underwent stent placement, three underwent esophageal stricture resection, and four underwent esophageal reconstruction. Four esophageal perforations (1%) developed after FBD. Antireflux surgery was performed in 18 patients (17%). There were no deaths. CONCLUSION FBD for anastomotic strictures after esophageal atresia repair is feasible and acceptably safe and provides relief of symptoms in most patients (90%); however, about half require more than one dilation, and surgery is best predicted if more than 10 dilations are required.


Journal of Pediatric Surgery | 2011

Outcomes of diverting jejunostomy for severe necrotizing enterocolitis

Mandela Thyoka; Simon Eaton; Edward M. Kiely; Joe Curry; David P. Drake; Kate Cross; Nigel J. Hall; A. Katy Khoo; Paolo De Coppi; Agostino Pierro

BACKGROUND/PURPOSE A diverting jejunostomy without bowel resection is an option for surgical management of extensive necrotizing enterocolitis (NEC). We aimed to determine outcomes of infants who underwent this operation. METHODS We collected clinical and outcome data on infants undergoing a diverting jejunostomy with no bowel resection as a primary procedure for extensive NEC. Data are median (range). RESULTS Seventeen neonates underwent a diverting jejunostomy. Eleven (65%) had multifocal disease, whereas 6 (35%) had pan-intestinal involvement. Perforation was seen in 7 (41%), all with multifocal disease. The stoma was placed 12 cm (8-45) from the duodenojejunal flexure. Six infants (35%) died, 4 of these within a day of operation, owing to persisting instability. Intestinal continuity was achieved in all survivors after 52 (17-83) days, and only 1 infant (9%) had a colonic stricture. Seven infants recovered without the need for further intestinal resection distal to the jejunostomy. In those that survived, parenteral nutrition was needed for 2.2 months (1.3-18.0). A single patient had short bowel syndrome. CONCLUSIONS A diverting jejunostomy is a useful surgical procedure that allows high survival and enteral autonomy in the treatment of extensive NEC. In most patients, the affected intestine recovers without further intestinal resection.


Journal of Pediatric Surgery | 2014

The outcome of critically ill neonates undergoing laparotomy for necrotising enterocolitis in the neonatal intensive care unit: a 10-year review

Naomi Jane Wright; Mandela Thyoka; Edward M. Kiely; Agostino Pierro; Paolo De Coppi; Kate Cross; David D. Drake; Mark J. Peters; Joe Curry

PURPOSE To evaluate outcomes in critically ill neonates with necrotising enterocolitis (NEC) undergoing a laparotomy in the neonatal intensive care unit (NICU). METHODS This is a retrospective review of neonates diagnosed with NEC who underwent a laparotomy on NICU between 2001 and 2011. Demographic, diagnostic, operative and outcome data were analysed. Nonparametric comparison was used. Data are reported as median (range). RESULTS 221 infants with NEC were referred for surgical evaluation; 182 (82%) underwent surgery; 15 (8%) required a laparotomy on NICU. Five had NEC totalis, 4 multifocal disease and 6 focal disease. Five had an open and close laparotomy, 8 stoma with/without bowel resection and 2 bowel resection and primary anastomosis. Ten (67%) died at a median of 6.5-hours (2-72) postoperatively; 2 died at 72 and 264-days. The 30-day mortality rate was higher (p=0.01) among infants undergoing a laparotomy on NICU (10/15; 67%) than in theatre (54/167; 32%). There was no significant difference in mean Paediatric Index of Mortality 2 Scores between survivors and nonsurvivors (p=0.55). Three (20%) infants remain alive with no or minimal disability at 1.4 (0.5-7.5) years. CONCLUSION Laparotomy for NEC on NICU is a treatment option for neonates who are too unstable to transfer to theatre. However, with 67% dying within 6.5-hours and a further 13% after months in hospital, we must consider whether surgery is always in their best interests. Development of a prediction model to help distinguish those at highest risk of long-term morbidity and mortality could help with decision making in this difficult situation.


European Journal of Pediatric Surgery | 2014

Clinical negligence claims in pediatric surgery in England: pattern and trends.

Mandela Thyoka

AIMS OF THE STUDY We hypothesized that there has been an increase in the number of successful litigation claims in pediatric surgery in England. Our aim was to report the incidence, causes, and costs of clinical negligence claims against the National Health Service (NHS) in relation to pediatric surgery. MATERIALS AND METHODS We queried the NHS Litigation Authority (NHSLA) on litigation claims among children undergoing pediatric surgery in England (2004-2012). We decided a priori to only examine closed cases (decision and payment made). Data included year of claim, year of payment of claim, payment per claim, paid-to-closed ratio, and severity of outcome of clinical incident. RESULTS Out of 112 clinical negligence claims in pediatric surgery, 93 (83%) were finalized-73 (65%) were settled and damages paid to the claimant and 20 (18%) were closed with no payment, and 19 (17%) remain open. The median payment was £13,537 (600-500,000) and median total cost borne by NHSLA was £31,445 (600-730,202). Claims were lodged at a median interval of 2 (0-13) years from time of occurrence with 55 (75%) cases being settled within the 3 years of being received. The commonest reasons for claims were postoperative complications (n=20, 28%), delayed treatment (n=16, 22%), and/or diagnosis (n=14, 19%). Out of 73, 17 (23%) closed claims resulted in case fatality. Conclusion: Two-thirds of all claims in pediatric surgery resulted in payment to claimant, and the commonest reasons for claims were postoperative complications, delayed treatment, and/or diagnosis. Nearly a quarter of successful claims were in cases where negligence resulted in case fatality. Pediatric surgeons should be aware of common diagnostic and treatment shortfalls as high-risk areas of increased susceptibility to clinical negligence claims.


Case Reports | 2014

Supraventricular tachycardia precipitated by a peripherally inserted central catheter in an infant with gastroschisis

Mandela Thyoka; Iram Haq; Gareth Hosie

Gastroschisis is a common congenital abdominal wall defect requiring surgical correction in early neonatal life. The time to full enteral feeds among infants with gastroschisis is variable. Gastroschisis remains a common surgical cause of intestinal failure in neonates. Peripherally inserted central catheters (PICC) are commonly used to provide long-term venous access for parenteral nutrition during the time enteral feeds are being slowly established. The PICC is placed under fluoroscopic guidance with the distal end of the catheter usually placed at the junction of the superior vena cava with the right atrium. In rare circumstances, the catheter tip may advance into intracardiac chambers, precipitating supraventricular re-entrant tachycardia. We report a case of an infant who was antenatally diagnosed with uncomplicated gastroschisis in whom a supraventricular tachycardia was precipitated by the PICC in the right atrium.


European Journal of Pediatric Surgery | 2013

Histologic and immunohistochemical features associated with outcome in neonatal necrotizing enterocolitis.

Simon Eaton; Nj Sebire; Mandela Thyoka; Agostino Pierro

INTRODUCTION The aim of the study was to compare histopathologic and immunohistochemical markers between survivors and nonsurvivors of surgical necrotizing enterocolitis (NEC). METHODS With appropriate ethical approval, archived resection specimens were identified for patients with NEC (Bell Stages II and III) for whom outcome data (survival yes/no) were available. For each specimen, a severely affected part of the bowel and the least affected area, usually the margin, were analyzed. Histologic findings were scored as no necrosis/mucosal necrosis/full-thickness necrosis and immunohistochemistry staining for inflammatory markers vascular cell adhesion protein (VCAM), CD68, CD20, intercellular adhesion molecule (ICAM), human leukocyte antigen (HLA-DR), CD3, Cleaved Caspase-3 (CC3), forkhead box P3 (FOXP3), CD62p, and C4d were performed and scored on a semiquantitative scale (0; no staining to 10, strong extensive staining). All samples were identified by only their study number throughout and the samples were analyzed completely blinded to all clinical information. Data were compared using chi-square test for trend (histologic data) or Mann-Whitney U test. RESULTS A total of 123 slides from 60 patients (birth weight 1.3 ± 0.1 kg, gestational age at birth 29.3 ± 0.6 weeks) were examined. Seventy-four specimens (60%) were from survivors and 49 specimens (40%) were from those who subsequently died. There was no relationship between histologic severity of necrosis (none/mucosal/full thickness) and mortality (p = 0.58). VCAM (adhesion molecule; p = 0.005) and CC3 (a marker of apoptosis,  p = 0.008) expression was significantly elevated in nonsurvivors, whereas there were no differences in CD68, CD20, ICAM, HLA-DR, CD3, FOXP3, CD62p, or C4d expression. CONCLUSIONS There is a poor relationship between histologic severity of bowel necrosis and patient survival in infants undergoing bowel resection for NEC. There is statistically increased expression of VCAM reflecting severity of systemic inflammatory response and evidence of increased apoptosis in the form of CC3 expression in those who subsequently die, but no histologic features can predict outcome.

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Dive into the Mandela Thyoka's collaboration.

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Edward M. Kiely

Great Ormond Street Hospital

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Joe Curry

Great Ormond Street Hospital

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Kate Cross

Great Ormond Street Hospital

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Simon Eaton

University College London

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Agostino Pierro

UCL Institute of Child Health

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David P. Drake

UCL Institute of Child Health

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Paolo De Coppi

University College London

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Nigel J. Hall

University of Southampton

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P De Coppi

Great Ormond Street Hospital

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Derek J. Roebuck

Great Ormond Street Hospital

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