Surgical management of complicated Crohn's disease

Surgical management of pediatric Crohn's disease is fundamentally palliative, aiming to treat the sequalae of complicated disease while preserving intestinal length. Multidisciplinary discussion of risk factors and quality of life should take place prior to operative intervention. Though the surgical management of pediatric Crohn's disease is largely based on the adult literature, there are considerations specific to the pediatric population - notably disease and treatment effects on growth and development. Intrabdominal abscess is approached with percutaneous drainage when feasible, reserving surgical intervention for the patient who is unstable or failing medical therapy. Pediatric patients with fibrostenotic disease should be considered for strictureplasty when possible, for maximum preservation of bowel length. Patients with medically refractory Crohn's proctocolitis should be treated initially with fecal diversion without proctocolectomy.

Does Delayed Diagnosis of Hirschsprung Disease Impact Post-operative and Functional Outcomes? A Multi-Center Review From the Pediatric Colorectal and Pelvic Learning Consortium

BACKGROUND

Hirschsprung Disease (HD) is a rare cause of functional bowel obstruction in children. Patients are typically diagnosed in the neonatal period and undergo pull-through (PT) soon after diagnosis. The optimal management and post-operative outcomes of children who present in a delayed fashion are unknown.

METHODS

A multi-center retrospective review of children with HD was performed at participating Pediatric Colorectal and Pelvic Learning Consortium sites. Children were stratified by age at diagnosis (neonates <29 days; infants 29 days-12 months; toddler 1 year-5 years and child >5 years).

RESULTS

679 patients with HD from 14 sites were included; Most (69%) were diagnosed in the neonatal period. Age at diagnosis was not associated with differences in 30-day complication rates or need for PT revision. Older age at diagnosis was associated with a greater likelihood of undergoing fecal diversion after PT (neonate 10%, infant 12%, toddler 26%, child 28%, P < 0.001) and a greater need for intervention for constipation or incontinence postoperatively (neonate 56%, infant 62%, toddler 78%, child 69%, P < 0.001).

CONCLUSION

Delayed diagnosis of HD does not impact 30-day post-operative outcomes or need for revision surgery but, delayed diagnosis is associated with increased need for fecal diversion after pull-through.

LEVEL OF EVIDENCE

III.

Does Length of Extended Resection Beyond Transition Zone Change Clinical Outcome for Hirschsprung Pull-Through?

INTRODUCTION

A proximal resection margin greater than 5 cm from the intra-operative histologically determined transition zone has been deemed necessary to minimize the risk of transition zone pull-through. This extended resection may require the sacrifice of vascular supply and even further bowel resection. The impact of extended proximal resection margin on post-operative complications and functional outcomes is unclear.

METHODS

A retrospective chart review of patients who underwent primary pull-through for Hirschsprung disease at a single institution between January 2008 and December 2022 was performed. An adequate proximal margin was defined by a circumferential normally ganglionated ring and absence of hypertrophic nerves. The extended margin was defined as the total length of proximal colon with normal ganglion cells and without hypertrophic nerves. Fecal incontinence severity was assessed with the Pediatric Fecal Incontinence Severity Score (PFISS).

RESULTS

Eighty seven patients met criteria for inclusion. Median age at primary pull-through was 17 days (IQR 10-92 days), 55% (n = 48) of patients had an extended proximal margin (EPM) ≤ 5 cm, and 45% (n = 39) had an EPM > 5 cm. An EPM ≤5 cm was not associated with increased rates of Hirschsprung associated enterocolitis (≤5 cm 43%, >5 cm 39%, P = 0.701), diversion post pull-through (≤5 cm 10%, >5 cm 5%, P = 0.367) or reoperation for transition zone pull-through (≤5 cm 3%, >5 cm 0%, P = 0.112). EPM ≤5 cm had more frequent involuntary daytime bowel movements (P = 0.041) and more frequent voluntary bowel movements (P = 0.035). There were no differences in other measures of fecal incontinence severity.

CONCLUSIONS

Shorter proximal extended margins beyond the adequate ganglionated margin do not significantly impact post-operative complication rates and have an unclear effect on fecal incontinence.

TYPE OF STUDY

Case Control.

LEVEL OF EVIDENCE

Level III.

Long-Term Male Sexual Function and Fecal Incontinence Outcomes for Adult Patients with Hirschsprung Disease or Anorectal Malformation

BACKGROUND

This study sought to characterize sexual function and fecal incontinence related quality of life (QOL) outcomes for adult males with anorectal malformation (ARM) or Hirschsprung's Disease (HD).

METHODS

We conducted a cross-sectional survey study of male patients ≥18 years with ARM or HD. Patients were identified from our institutional database, contacted and consented by telephone, and sent a REDCap survey via email. The International Index of Erectile Function (IIEF-5) and Male Sexual Health Questionnaire (MSHQ) evaluated erectile dysfunction (ED) and ejaculatory dysfunction (EjD), respectively. The Cleveland Clinic Incontinence Score (CCIS) and the Fecal Incontinence Quality of Life Scale (FIQLS) assessed fecal incontinence-related outcomes. A linear regression analysis of IIEF-5 scores compared to CCIS scores was used to evaluate for an association between ED and incontinence.

RESULTS

Of 63 patients contacted, 48 completed the survey. The median age for respondents was 22.5 years (IQR 20-25). There were 19 patients with HD and 29 patients with ARM. On the IIEF-5 survey, 35.3% report some level of ED. On the MSHQ-EjD survey, the median score was 14 out of 15 (IQR 10.75-15), indicating few EjD concerns. The median CCIS was 5 (IQR 2.25-7.75) and the median FIQL scores ranged from 2.7 to 3.5 depending on the domain assessed, demonstrating some QOL challenges secondary to fecal incontinence. On linear regression analysis, IIEF-5 and CCIS scores were weakly associated (B = -0.55, p = 0.045).

CONCLUSIONS

Male adult patients with ARM or HD may have ongoing concerns with sexual function and fecal incontinence.

LEVEL OF EVIDENCE

Level 4.

TYPE OF STUDY

Cross-Sectional Survey Study.

Sacral Nerve Stimulation in Children with Medically Refractory Fecal Incontinence or Severe Constipation

INTRODUCTION

The goal of this study was to evaluate outcomes in patients treated with sacral nerve stimulation (SNS) for medically refractory fecal incontinence or severe constipation.

METHODS

We performed a retrospective cohort study of all patients treated with SNS after failed medical management at a single center between 9/1/2015 and 6/30/2022. Demographic and clinical data was extracted from the electronic medical record. Rates of involuntary bowel movements were evaluated using a bowel severity score questionnaire and compared pre- and post-SNS using McNemar and McNemar-Bowker tests.

RESULTS

70 patients underwent SNS placement. The median age was 12.8 years (IQR 8.6-16.0) and 61.4% were male. The most common diagnosis was idiopathic constipation (67.1%), followed by anorectal malformation (15.7%), and others. 43 patients had severity scores recorded both pre- and at least 90 days post-SNS insertion. The rates of daytime and nighttime involuntary bowel movements were significantly different pre-compared to post-SNS placement (p = 0.038 and p = 0.049, respectively). The rate of daytime and nighttime fecal continence increased from 44% to 58.1% and 53.5%-83.7%, respectively. The rate of at least weekly daytime and nighttime fecal incontinence decreased from 48.8% to 18.7% and 34.9%-7.0%, respectively. Minor pain/neurological symptoms occurred in 40% of patients, while 5.7% developed a wound infection. Further surgery for the SNS was required in 40% of patients.

CONCLUSIONS

SNS placement can be an effective treatment for medically refractory fecal incontinence. Minor complications and the need for further procedures are common, while more serious complications like wound infections are rare.

TYPE OF STUDY

Retrospective Cohort Study.

LEVEL OF EVIDENCE

Level 3.

Rectal Prolapse Following Repair of Anorectal Malformation: Incidence, Risk Factors, and Management

BACKGROUND

The incidence and optimal management of rectal prolapse following repair of an anorectal malformation (ARM) has not been well-defined.

METHODS

A retrospective cohort study was performed utilizing data from the Pediatric Colorectal and Pelvic Learning Consortium registry. All children with a history of ARM repair were included. Our primary outcome was rectal prolapse. Secondary outcomes included operative management of prolapse and anoplasty stricture following operative management of prolapse. Univariate analyses were performed to identify patient factors associated with our primary and secondary outcomes. A multivariable logistic regression was developed to assess the association between laparoscopic ARM repair and rectal prolapse.

RESULTS

A total of 1140 patients met inclusion criteria; 163 (14.3%) developed rectal prolapse. On univariate analysis, prolapse was significantly associated with male sex, sacral abnormalities, ARM type, ARM complexity, and laparoscopic ARM repairs (p < 0.001). ARM types with the highest rates of prolapse included rectourethral-prostatic fistula (29.2%), rectovesical/bladder neck fistula (28.8%), and cloaca (25.0%). Of those who developed prolapse, 110 (67.5%) underwent operative management. Anoplasty strictures developed in 27 (24.5%) patients after prolapse repair. After controlling for ARM type and hospital, laparoscopic ARM repair was not significantly associated with prolapse (adjusted odds ratio (95% CI): 1.50 (0.84, 2.66), p = 0.17).

CONCLUSION

Rectal prolapse develops in a significant subset of patients following ARM repair. Risk factors for prolapse include male sex, complex ARM type, and sacral abnormalities. Further research investigating the indications for operative management of prolapse and operative techniques for prolapse repair are needed to define optimal treatment.

TYPE OF STUDY

Retrospective cohort study.

LEVEL OF EVIDENCE

II.

Hirschsprung-Associated Enterocolitis at a Referral Institution: A Retrospective Review

BACKGROUND

Hirschsprung-associated enterocolitis (HAEC) is the most common cause of morbidity and mortality amongst patients with Hirschsprung disease (HD); rectal Botulinum toxin (Botox) has been reported a possible prevention strategy. We aimed to evaluate our institution's historic cohort of HD patients, first to determine our incidence of HAEC and second to begin assessing the effect of Botox on HAEC incidence.

METHODS

Patients with HD seen at our institution between 2005 and 2019 were reviewed. Incidence of HD and frequencies of HAEC and Botox injections were tallied. Associations between initial Botox treatment or transition zone and HAEC incidence were evaluated.

RESULTS

We reviewed 221 patients; 200 were included for analysis. One hundred thirteen (56.5%) patients underwent primary pull-through at a median age of 24 days (IQR 91). Eighty-seven (43.5%) patients with initial ostomy had their intestinal continuity reestablished at a median of 318 days (IQR 595). Ninety-four (49.5%) experienced at least one episode of HAEC and 62 (66%) experienced multiple episodes of HAEC. Nineteen (9.6%) patients had total colonic HD and had an increased total incidence of HAEC compared to patients without total colonic HD (89% vs 44%, p < 0.001). Six (2.9%) patients received Botox injections at the time of pull-through or ostomy takedown; one experienced an episode of HAEC (versus 50.7% of the patients who were confirmed to have not received Botox injections at their surgery, p = 0.102).

CONCLUSION

Further prospective study on Botox's effect on Hirschsprung-associated enterocolitis is required and is the next step in our investigation.

LEVEL OF EVIDENCE

Level III.

Antithrombin III infusion improves anticoagulation in congenital diaphragmatic hernia patients on extracorporeal membrane oxygenation

PURPOSE

Achieving effective anticoagulation during neonatal extracorporeal membrane oxygenation (ECMO) without increasing the risk of hemorrhage remains challenging. The use of antithrombin III (AT-III) for this purpose has been examined, but studies have been limited to intermittent bolus dosing. We aimed to evaluate the efficacy and safety of an institutionally developed AT-III continuous infusion protocol in neonates receiving ECMO for the treatment of congenital diaphragmatic hernia (CDH).

METHODS

In this single center, retrospective study, all neonates with a CDH who received ECMO support during the study period were included. Data on anticoagulation labs and therapy, life-threatening bleeding, and circuit changes were analyzed.

RESULTS

Eleven patients were divided into two groups: patients with AT-III continuous infusion (n = 5) and without (n = 6). There were no differences in the gestational age (p = 0.29), sex (p = 1.00), ECMO duration (p = 0.59), or initial AT-III levels (p = 0.76) between groups. Patients in the AT-III infusion group had on average 18.5% higher AT-III levels (p < 0.0001). Patients receiving continuous AT-III infusions spent a significantly higher percentage of ECMO time within the therapeutic range, measured using anti-Factor Xa levels (64.9±4.2% vs. 29.1±8.57%, p = 0.008), and required fewer changes to the heparin infusion rate (6.48±0.88 vs 2.38±0.36 changes/day changes/day, p = 0.005). Multivariate analysis revealed continuous infusion of AT-III did not increase the rate of intracranial or surgical bleeding (p = 0.27).

CONCLUSION

AT-III as a continuous infusion in CDH neonates on ECMO provides a decreased need to modify heparin infusion and more consistent therapeutic anticoagulation without increasing the risk of life-threatening bleeding.

Hospital and Professional Charges and Reimbursement Patterns in Pediatric Extracorporeal Membrane Oxygenation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is an expensive therapeutic modality. We sought to identify the main charge contributors to patient bills and analyze their patterns of reimbursement. We additionally sought to evaluate the impact of 2015 Current Procedural Terminology (CPT) code changes in professional billing for pediatric surgeons.

METHODS

A retrospective review of ECMO cases at a standalone quaternary children's hospital between 2008-2017 was performed. Itemized hospital and professional bills were analyzed.

RESULTS

Top charges included room rates, nitric oxide, medications, invasive support and monitoring, and laboratory testing. Average reimbursement was ∼60% for hospital and ∼36% for professional bills. CPT code changes in 2015 represented a 65% reduction in RVUs and 46% reduction in professional charges. Medicaid reimbursement for professional billing remained stable at 9%, and commercial reimbursement fell from 70% to 59% during the study period.

CONCLUSIONS

The main drivers of ECMO charges are unrelated to ECMO supplies or surgery. Evidence-based guidelines for ECMO management could make a difference in healthcare expenditure. Modern CPT codes depreciate RVUs and professional charges, compromising revenue. As the infrastructure required to provide this service is costly, diminishing returns may limit access to this therapy.

Surgical history of Hirschsprung disease

Harald Hirschsprung presented the first comprehensive and detailed description of clinical outcomes in patients with congenital megacolon. In the century following his discovery, we have seen realization of the etiology, diagnosis, and treatment of Hirschsprung disease. In this article we describe the surgical management of Hirschsprung disease starting with Orvar Swenson, who pioneered the field with the first full thickness transrectal dissection followed by several additional innovative surgeons who have contributed to the modifications that have brought us to the modern surgical management of Hirschsprung Disease.

A child presents with perianal symptoms - how often is this Crohn's disease?

BACKGROUND

The cumulative incidence and predictors of future diagnosis of Crohn's disease (CD) following presentation with perianal symptoms, such as anorectal abscess, fistula or fissure, is unknown.

METHODS

A 5-year retrospective review of children presenting with perianal symptoms without prior CD diagnosis was performed. Institutional cumulative incidence of CD was calculated to determine the risk of CD presenting with perianal symptoms.

RESULTS

1140 children presented for evaluation of an anorectal abscess (n = 232), fistula (n = 49), or fissure (n = 859). Thirty-five were later diagnosed with CD, resulting in an incidence of 3%. Prognostic indicators of future CD diagnosis included increased age per every additional year (RR 1.19, 95% CI: 1.14-1.25, p < 0.001), male sex (RR 2.12, 95% CI 1.07-4.22, p = 0.024), or perianal fistula (RR 4.67, 95% CI 2.26-9.67, p = 0.022). Among those diagnosed with CD, 57% experienced and had a documented history of a CD-associated symptom prior to perianal symptom onset. Absence of symptoms resulted in delayed diagnosis (43 vs 3 days, p < 0.02).

CONCLUSION

Of children presenting with a perianal symptom, three percent will eventually be diagnosed with CD. At highest risk (35%) were males aged 10 years or older with a perianal fistula; which should prompt expeditious workup.

Creating a collaborative program for the care of children with colorectal and pelvic problems

The treatment of patients with colorectal disorders and their associated urologic, gynecologic, gastrointestinal, spinal, and orthopedic anomalies requires care from various medical and surgical specialties over the course of their lifetime. This is ideally handled by a collaborative center which facilitates the assessment and development of a long-term patient care plan among multiple specialties which can enhance the quality of care, improve communication among different specialties, and improve patient satisfaction and outcomes. We describe the process, as well as lessons learned in developing such a center.

Hemorrhage after on-ECMO repair of CDH is equivalent for muscle flap and prosthetic patch

BACKGROUND/PURPOSE

Prosthetic patch (patch) and muscle flap (flap) techniques are utilized for severe congenital diaphragmatic hernia (CDH) repair; however, when performed on extracorporeal membrane oxygenation (ECMO), the risk of hemorrhage increases. We sought to compare bleeding complications between repair types.

METHODS

We retrospectively reviewed 2010-2016 on-ECMO CDH repairs.

RESULTS

Twenty-nine patients met criteria: 13 patch (44.8%) and 16 flap (55.2%). Eight patch (61.5%) and 13 flap (81.2%) patients had left-sided defects (p = 0.223). All defects were Type C or D (Type C: patch 53.8%, flap 56.2%, p = 0.596). There was no difference in gestational age at delivery (patch 37.5 ± 0.9 weeks, flap 37.2 ± 1.3 weeks, p = 0.390) or age at repair (patch 7.46 ± 6.6 days, flap 6.00 ± 4.3 days, p = 0.476). Seven patch (53.8%) and 9 flap (56.2%) patients survived to discharge (p = 0.596). Estimated intraoperative blood loss was equivalent (patch 35.3 ± 53.9 mL, flap 24.2 ± 18.4 mL, p = 0.443). One patch patient (7.6%) and two (12.5%) flap patients required reoperation in the first 48 h for bleeding (p = 0.580). 48-h postoperative transfusions were the same for those that required reoperation (patch 282.0 mL/kg, flap 208.5 ± 21.9 mL/kg, p = 0.054) and those that did not (patch 120.7 ± 111.7 mL/kg, flap 118.4 ± 89.9 mL/kg, p = 0.561).

CONCLUSIONS

On-ECMO bleeding complications are equivalent for both flap and patch CDH repair.

LEVEL OF EVIDENCE

Type III (retrospective comparative study).

A comparison of surgical complications after appendicostomy and neoappendicostomy in pediatric patients

PURPOSE

There are limited data on neoappendicostomy complications owing to small patient populations. This study compares appendicostomy and neoappendicostomy procedures with an emphasis on major postoperative complications requiring either a surgical or interventional radiology procedure.

METHOD

A single-institution retrospective review included all patients with complete medical charts in the Cincinnati Children's Colorectal Database who underwent either an appendicostomy or neoappendicostomy from August 2005 through December 2016. Demographics, details of the procedure, and major postoperative complications were evaluated.

RESULTS

261 patients (appendicostomy n = 208, neoappendicostomy n = 53) with a median follow up time of 2.5 years resulted in 84 patients (appendicostomy n = 60, neoappendicostomy n = 24) experiencing a total of 118 complications requiring surgical or radiologic intervention with a significant difference between the groups (29% vs 45%, RR = 1.79 (95% CI: 1.24-2.60), p < 0.01). Skin level stricture was the most common complication (20% appendicostomies vs 30% neoappendicostomies, p = 0.13).

CONCLUSIONS

Appendicostomies and neoappendicostomies can be an effective way to manage fecal incontinence; however, 32% of our patients experienced a complication that required either a surgical or interventional radiology procedure. Patients need to be informed of the possible complications that are associated with appendicostomy and neoappendicostomy construction.

TYPE OF STUDY

Single institution retrospective review.

LEVEL OF EVIDENCE

IV.

Initial development and validation of a fecal incontinence-specific quality of life measure

BACKGROUND/PURPOSE

Fecal incontinence is a prevalent pediatric condition with psychosocial impacts on both children and their caregivers. We sought to develop and validate the Cincinnati Fecal Incontinence Scale (CINCY-FIS) as a psychometrically valid measure to assess the quality of life and caregiver impacts of pediatric fecal incontinence.

METHODS

Items were generated through review of previous measures, expert consensus, and pilot testing with feedback from 8 families. Initial study measures were completed by 222 caregivers. Following item reduction, 18 items were subjected to confirmatory factor analysis. Convergent and criterion validity were assessed using correlation. Reliability was established using internal consistency statistics and test-retest reliability at baseline and 2-week follow-up.

RESULTS

A five factor first-order structure with two higher-order factors demonstrated acceptable fit to the data, was consistent with a priori hypotheses, and was more parsimonious than the alternative model. Convergent validity and criterion-related validity were established for all of the CINCY-FIS scales. Reliability was high and consistent across both measurement occasions.

CONCLUSIONS

The CINCY-FIS is a reliable and valid assessment of pediatric fecal incontinence-specific quality of life and parenting stress. The score is highly sensitive to patient changes making it suitable for both clinical and research purposes.

TYPE OF STUDY

Prospective observational.

LEVEL OF EVIDENCE

Study of Diagnostic Test Level II.

Clinical and urodynamic outcomes in children with anorectal malformation subtype of recto-bladder neck fistula

INTRODUCTION

Patients with anorectal malformations (ARMs) have a high incidence of genitourinary anomalies. Those with a recto-bladder neck fistula may represent a high-risk group, but their long-term urologic outcomes are poorly described.

OBJECTIVE

To evaluate the clinical and urodynamic outcomes in a large cohort of patients with an ARM subtype of recto-bladder neck fistula.

MATERIALS AND METHODS

A retrospective cohort study was performed of patients who had been treated for a recto-bladder neck fistula at the present institution since 2007. The primary outcomes were the ability to achieve urinary continence after 4 years of age, and development of a mildly decreased glomerular filtration rate (GFR) or worse (<89 ml/min/1.73 m²). Continence was defined as the ability to store urine for 3-4 h during the day and 8 h overnight without leakage.

RESULTS

Demographic and clinical data are provided in the Summary Table. The most recent urodynamic findings included the presence of detrusor overactivity in 30 (75%) patients, median leak point pressure of 56.0 cmH₂O (range, 14-140), median functional cystometric capacity at 40 cmH₂O of 125.5% age-expected capacity (range, 36-473%), and median maximum cystometric capacity of 131.0% age-expected capacity (range, 44-473%). A mildly decreased GFR or worse developed in 13 (24%) patients. Of the 52 (78%) patients who were followed by pediatric urology at the present institution with a median follow-up of 30.9 months (range, 0.0-86.8), 35 (67%) were at least 4 years of age and could be assessed for continence. Continence was achieved in five (14%) patients voiding spontaneously and 15 (43%) performing CIC. Recurrent urinary tract infections (UTI) (OR 0.70, P = 0.006) were an independent predictor of incontinence, while urethral anomalies (OR 1.40, P = 0.03) were an independent predictor of chronic kidney disease (CKD) on multiple logistic regression analysis.

DISCUSSION

The findings favorably compared with other studies, but were more robust due to the size of the cohort and breadth of urologic evaluation. Limitations included the retrospective design at a single institution. Incomplete clinical data and misclassification of continence may have lead to bias.

CONCLUSIONS

This large cohort of patients with an ARM subtype of recto-bladder neck fistula had a high incidence of genitourinary anomalies. They were rarely able to achieve continence with spontaneous voiding alone and were at risk of developing CKD, both of which were likely multifocal in origin. Long-term urologic follow-up is warranted for patients with a recto-bladder neck fistula.

Complications in colorectal surgery

Colorectal pediatric surgery is a diverse field that encompasses many different procedures. The pullthrough for Hirschsprung disease, the posterior sagittal anorectoplasty for anorectal malformations including complex cloaca reconstructions and the ileal pouch anal anastomosis for ulcerative colitis and familial adenomatous polyposis present some of the most technically challenging procedures pediatric surgeons undertake. Many children prevail successfully following these surgical interventions, however, a small number of patients suffer from complications following these procedures. Anticipated postoperative problems are discussed along with medical and surgical strategies for managing these complications.

Extensive heterotopic gastric mucosa of the small intestine: imaging with 99mTc-sodium pertechnetate SPECT/CT enterography

Extensive heterotopic gastric mucosa of the small intestine is a rare, but potentially life-threatening condition characterized by multifocal or long-segment heterotopic gastric mucosa within the bowel lumen that is often associated with other anomalies including malrotation and annular pancreas. Although the imaging findings are characteristic, this entity may be unrecognized due to its unusual imaging appearance and rarity. CT or MR enterography and ^99mTc-sodium pertechnetate scintigraphy can provide complementary information that enables specific diagnosis and accurate assessment of disease extent. We present a case of extensive heterotopic gastric mucosa of the small intestine imaged by simultaneous, combined ^99mTc-sodium pertechnetate single photon-emission computed tomography (SPECT)/CT enterography to both familiarize the reader with the condition and describe an imaging strategy that enables specific diagnosis and assists with treatment planning.

The association of the severity of anorectal malformations and intestinal malrotation

INTRODUCTION

Intestinal malrotation is a known association of anorectal malformations (ARM). Exact incidence, prognosis and surgical implications related to ARM are unknown. The aim of this study was to identify relevant associations between ARM and the presence of malrotation.

METHODS

Records of patients from two referral centers were retrospectively analyzed looking for malrotation associated to ARM and its management, as well as factors for functional prognosis.

RESULTS

40 patients out of 2572 with ARM (1.6%) were found to have malrotation. Females were more commonly affected, and severe malformations were more frequent (cloaca, covered cloacal exstrophy in females and rectoprostatic and rectobladder neck fistula in males). Factors significantly associated with malrotation included Müllerian or Wolffian duct anomalies (P<0.05), while fecal continence status, presence of constipation, and use of laxatives or enemas were not. Detecting and correcting malrotation early on or at the time of colostomy creation represented a protective factor against additional surgeries for bowel obstruction and volvulus (P<0.001). Removal of the appendix during malrotation treatment required constructing a neoappendicostomy using a cecal flap in 9 out of 14 patients needing antegrade enema administration.

CONCLUSIONS

Malrotation presence in patients with ARM has the same frequency as in the general population, but it is more common in severe malformations. Surgeons treating these patients should address the malrotation at the time of colostomy opening if detected. The appendix should be preserved for potential future use as an appendicostomy for antegrade administration of enemas.

Angiogenesis and Vascular Endothelial Growth Factor-A Expression Associated with Inflammation in Pediatric Crohn's Disease

BACKGROUND AND AIMS

Angiogenesis is a component of chronic inflammatory diseases including inflammatory bowel disease. Some studies describe increased angiogenesis associated with acute disease in adult Crohn's disease and ulcerative colitis, while animal models aid investigations of mechanism and pathophysiology of angiogenesis. We aim to explore the role of angiogenesis and its pathways in pediatric Crohn's disease.

METHODS

Surgical specimens were obtained from pediatric Crohn's disease (both inflamed and non-inflamed regions of ileum) and control patients. Samples were examined for inflammation, microvessel density, and molecular expression of vascular endothelial growth factor-A, platelet-derived growth factor-β, angiopoietin-1, and angiopoietin-2.

RESULTS

Angiogenesis and inflammation were increased in parallel in Crohn's disease compared to controls. We also discovered increased angiogenesis in Crohn's disease tissue that was relatively free of inflammatory disease. Vascular endothelial growth factor-A gene expression (P = 0.034) was elevated in Crohn's disease over controls, while gene expression of platelet-derived growth factor-β (P = 0.069), angiopoietin-1 (P = 0.206), and angiopoietin-2 (P = 0.082) was not significantly elevated.

CONCLUSIONS

We confirm that inflammation-associated angiogenesis is upregulated in pediatric Crohn's disease. This population also exhibits elevated mucosal angiogenesis at the surgical margin with limited inflammation. This suggests that angiogenesis is an additional pathologic characteristic to potentially identify normal mucosa and margins of surgical resection that are uninvolved with disease and, furthermore, may have implications for monitoring complete disease remission. We further identify the vascular endothelial growth factor-A pathway involvement in the disease process, which may serve as a future molecular target for anti-angiogenic therapy in inflammatory bowel disease.

Pyloric atresia with epidermolysis bullosa: fetal MRI diagnosis with postnatal correlation

Pyloric atresia is an uncommon congenital gastric outlet obstruction, accounting for only 1% of gastrointestinal atresias. Up to 55% of cases have associated anomalies, the most common of which is epidermolysis bullosa. Fetal MRI findings of the epidermolysis bullosa-pyloric atresia association have not been previously reported. We present a case of this association diagnosed by prenatal MRI with corroborative postnatal imaging and surgical findings.

The role of a colon resection in combination with a Malone appendicostomy as part of a bowel management program for the treatment of fecal incontinence

PURPOSE

Surgical options previously described by us as part of a bowel management program for the treatment of soiling and fecal incontinence include (1) resection of a megarectosigmoid to reduce a patient's laxative requirement or (2) a Malone appendicostomy in patients who require enemas. We have found that some patients may benefit from both procedures.

METHODS

We reviewed 18 fecally incontinent patients with structural or functional disorders of the anorectosigmoid (16 ARM, 1 spina bifida, and 1 SCT) who underwent both procedures.

RESULTS

Of 18 patients, the enema regimen prior to resection had an average volume of 681 ml of saline (Range 400-1000 ml) and 60 ml (Range 48-117 ml) of additives (glycerine, castile soap and/or phosphate). Following the colon resection, the average volume of saline and additives was 335 ml (Range 130-650 ml) and 25 ml (Range 0-60 ml), respectively, a 50% reduction for both (P<0.01). The time for enema administration and evacuation was reduced by 25%, and the enemas were more effective, rendering the patients clean in 18 of 18 cases (follow-up was 3 months to 21 years). 2 patients later demonstrated that they could be managed with laxatives alone.

CONCLUSION

In patients with poor continence potential and a megarectosigmoid, combining a colon resection with a Malone appendicostomy can make the enema more effective. In some rare cases we found the resection may allow for a better response to laxatives.

Paediatric Crohn disease patients with stricturing behaviour exhibit ileal granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibody production and reduced neutrophil bacterial killing and GM-CSF bioactivity

Granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies are associated with stricturing behaviour in Crohn disease (CD). We hypothesized that CD ileal lamina propria mononuclear cells (LPMC) would produce GM-CSF autoantibodies and peripheral blood (PB) samples would contain GM-CSF neutralizing capacity (NC). Paediatric CD and control PBMC and ileal biopsies or LPMC were isolated and cultured and GM-CSF, immunoglobulin (Ig)G and GM-CSF autoantibodies production were measured by enzyme-linked immunosorbent assay (ELISA). Basal and GM-CSF-primed neutrophil bacterial killing and signal transducer and activator of transcription 5 (STAT5) tyrosine phosphorylation (pSTAT5) were measured by flow cytometry. GM-CSF autoantibodies were enriched within total IgG for LPMC isolated from CD ileal strictures and proximal margins compared to control ileum. Neutrophil bacterial killing was reduced in CD patients compared to controls. Within CD, neutrophil GM-CSF-dependent STAT5 activation and bacterial killing were reduced as GM-CSF autoantibodies increased. GM-CSF stimulation of pSTAT5 did not vary between controls and CD patients in washed PB granulocytes in which serum was removed. However, GM-CSF stimulation of pSTAT5 was reduced in whole PB samples from CD patients. These data were used to calculate the GM-CSF NC. CD patients with GM-CSF NC greater than 25% exhibited a fourfold higher rate of stricturing behaviour and surgery. The likelihood ratio (95% confidence interval) for stricturing behaviour for patients with elevation in both GM-CSF autoantibodies and GM-CSF NC was equal to 5 (2, 11). GM-CSF autoantibodies are produced by LPMC isolated from CD ileal resection specimens and are associated with reduced neutrophil bacterial killing. CD peripheral blood contains GM-CSF NC, which is associated with increased rates of stricturing behaviour.

Foregut duplication cyst associated with esophageal atresia and tracheoesophageal fistula: a case report and literature review

A case of esophageal atresia associated with a foregut duplication cyst is reported and the literature reviewed. This is the first documented occurrence in conjunction with Down syndrome and the second case where both anomalies were treated at the initial surgery.

VEGF blockade enables oncolytic cancer virotherapy in part by modulating intratumoral myeloid cells

Understanding the host response to oncolytic viruses is important to maximize their antitumor efficacy. Despite robust cytotoxicity and high virus production of an oncolytic herpes simplex virus (oHSV) in cultured human sarcoma cells, intratumoral (ITu) virus injection resulted in only mild antitumor effects in some xenograft models, prompting us to characterize the host inflammatory response. Virotherapy induced an acute neutrophilic infiltrate, a relative decrease of ITu macrophages, and a myeloid cell-dependent upregulation of host-derived vascular endothelial growth factor (VEGF). Anti-VEGF antibodies, bevacizumab and r84, the latter of which binds VEGF and selectively inhibits binding to VEGF receptor-2 (VEGFR2) but not VEGFR1, enhanced the antitumor effects of virotherapy, in part due to decreased angiogenesis but not increased virus production. Neither antibody affected neutrophilic infiltration but both partially mitigated virus-induced depletion of macrophages. Enhancement of virotherapy-mediated antitumor effects by anti-VEGF antibodies could largely be recapitulated by systemic depletion of CD11b(+) cells. These data suggest the combined effect of oHSV virotherapy and anti-VEGF antibodies is in part due to modulation of a host inflammatory reaction to virus. Our data provide strong preclinical support for combined oHSV and anti-VEGF antibody therapy and suggest that understanding and counteracting the innate host response may help enable the full antitumor potential of oncolytic virotherapy.

Pretreatment with anti-VEGF therapy may exacerbate inflammation in experimental acute colitis

AIM

Our previous investigations of angiogenesis in inflammatory bowel disease showed that vascular endothelial growth factor (VEGF) blockade reduced colonic neovascularization and inflammation. We hypothesized that pretreatment with bevacizumab, a monoclonal anti-VEGF antibody, would attenuate the severity of angiogenesis and inflammation in a murine model of colitis.

METHODS

C57BL/6 mice were treated with intraperitoneal injections of bevacizumab (250 μg/dose) before induction of colitis with dextran sulfate sodium (DSS). The colons were examined at predetermined time points. Colonic inflammation and microvessel density were assessed microscopically.

RESULTS

All mice acutely developed melena and weight loss (18.8% ± 1.1% control vs 20.2% ± 1.1% treated, P = .37) and regained a similar weight percentage after the recovery (26.5% ± 4.0% vs 20.9% ± 4.4%, P = .37). Microvessel density acutely increased in both groups in response to DSS, with a trend toward inhibited angiogenesis in the treated group at the conclusion of the acute phase (194,100 ± 14,240 vs 149,400 ± 17,590 μm(2), P = .11). Bevacizumab-treated mice exhibited significantly increased inflammation after the acute phase (8.3 ± 0.8 vs 13.0 ± 2.0, P = .05), but were similar to control after the recovery (7.3 ± 1.5 vs 5.5 ± 1.0, P = .27).

CONCLUSIONS

Preemptive VEGF inhibition does not significantly attenuate angiogenesis and, in fact, worsens inflammation in a model of acute colitis. Preventive VEGF blockade may disrupt healing and exacerbate injury via alternative angiogenic or inflammatory pathways.

Pediatric hernia repair: 1-stop shopping

PURPOSE

Multiple visits for the evaluation, treatment, and follow-up of straightforward surgical problems are inconvenient, can result in lost work for the parents, and missed school for the child. We hypothesized that with proper previsit screening, patients with select diagnoses can be evaluated in an outpatient clinic setting and undergo operation the same day.

METHODS

Criteria were developed to identify straightforward referrals to our surgical practice for umbilical, epigastric, or inguinal hernias. Scripting was created to offer families the option of consultation and, if indicated, surgical treatment on the same day. Data collected included number of patients, cases performed, insurance status, and consultation reimbursement and surgical fees. Families were surveyed postoperatively.

RESULTS

Sixty-one patient candidates participated. The diagnosis and indication for surgery were confirmed in 56 (92%), of which 50 underwent repair the day of their consultation. Seventy-two percent of patients had commercial insurance, whereas 28% had Medicaid. The preoperative consultation fee was reimbursed in 39 (78%) of 50 encounters (57% Medicaid, 86% commercial). All surgical cases were reimbursed. Patient and family satisfaction was high.

CONCLUSIONS

We conclude that it is feasible to provide same-day evaluation and service for straightforward pediatric hernias with acceptable financial reimbursement and high parent satisfaction.

Late gestation fetal magnetic resonance imaging-derived total lung volume predicts postnatal survival and need for extracorporeal membrane oxygenation support in isolated congenital diaphragmatic hernia

PURPOSE

Magnetic resonance imaging (MRI) has been used as an imaging modality to assess pulmonary hypoplasia in congenital diaphragmatic hernias (CDHs). The objective of this study was to determine if there is a correlation between late gestational fetal MRI-derived total lung volumes (TLVs) and CDH outcomes.

METHODS

From 2006 to 2009, 44 patients met criteria of an isolated CDH with a late gestational MRI evaluation. The prenatal TLV (in milliliters) was obtained between 32 and 34 weeks gestation. The measured study outcomes included survival, need for extracorporeal membrane oxygenation (ECMO), and length of stay.

RESULTS

There were 39 left and 5 right CDH patients. The average TLV was significantly lower for nonsurvivors (P = .01), and there was a significant association between lower TLV and the need for ECMO (P = .0001). When stratified by TLV, patients with a TLV of greater than 40 mL had a 90% survival vs 35% survival for a TLV of less than 20 mL. Furthermore, patients with a TLV greater than 40 mL had a lower rate of ECMO use (10%) than patients with a TLV of less than 20 mL (86%). Shorter length of stay was found to correlate with increasing TLV (P = .022).

CONCLUSION

Late gestation fetal MRI-derived TLV significantly correlates with postnatal survival and need for ECMO. Fetal MRI may be useful for the evaluation of patients who present late in gestation with a CDH.

The utility of routine pouchogram before ileostomy reversal in children and adolescents following ileal pouch anal anastomosis

INTRODUCTION

Pouchograms are used to assess the integrity of the ileal pouch anal anastomosis (IPAA) in patients who have undergone restorative proctocolectomy. Its benefits have been questioned, and there are no data to support the routine use in children.

METHODS

We retrospectively reviewed the charts of 26 patients who had an IPAA and pouchogram at our institution between 2001 and 2009. Each patient also underwent an examination under anesthesia to assess the integrity of the IPAA on the day of the ileostomy closure.

RESULTS

The mean age of the patients was 13.8 (± 0.7) years. The pouchogram was performed at a median of 6 weeks after the IPAA (range, 4-20 weeks). The findings were normal in 26 (89.7%) and demonstrated stricture in 2 (6.9%) and leak in 1 (3.4%). History was suggestive and physical examination was confirmatory in these 3 problematic cases.

CONCLUSIONS

A contrast enema is not routinely required to evaluate the integrity of the IPAA before ileostomy reversal in pediatric patients. Complications can be detected by history and rectal examination before ileostomy closure. We recommend the use of contrast enema only in symptomatic patients where a leak is suspected, thereby limiting radiation exposure and inconvenience.

Cancer screening by systemic administration of a gene delivery vector encoding tumor-selective secretable biomarker expression

Cancer biomarkers facilitate screening and early detection but are known for only a few cancer types. We demonstrated the principle of inducing tumors to secrete a serum biomarker using a systemically administered gene delivery vector that targets tumors for selective expression of an engineered cassette. We exploited tumor-selective replication of a conditionally replicative Herpes simplex virus (HSV) combined with a replication-dependent late viral promoter to achieve tumor-selective biomarker expression as an example gene delivery vector. Virus replication, cytotoxicity and biomarker production were low in quiescent normal human foreskin keratinocytes and high in cancer cells in vitro. Following intravenous injection of virus >90% of tumor-bearing mice exhibited higher levels of biomarker than non-tumor-bearing mice and upon necropsy, we detected virus exclusively in tumors. Our strategy of forcing tumors to secrete a serum biomarker could be useful for cancer screening in high-risk patients, and possibly for monitoring response to therapy. In addition, because oncolytic vectors for tumor specific gene delivery are cytotoxic, they may supplement our screening strategy as a "theragnostic" agent. The cancer screening approach presented in this work introduces a paradigm shift in the utility of gene delivery which we foresee being improved by alternative vectors targeting gene delivery and expression to tumors. Refining this approach will usher a new era for clinical cancer screening that may be implemented in the developed and undeveloped world.

Submucosal gland development in the human fetal trachea xenograft model: implications for fetal gene therapy

BACKGROUND/PURPOSE

Our previous work in a human-fetal trachea xenograft model suggests potential benefits of treating cystic fibrosis in utero. The target for postnatal gene therapy in cystic fibrosis is tracheal submucosal glands (SMGs). The aim of this study was to determine if SMG development in our model recapitulates normal trachea development and its validity for studying fetal gene transfer.

METHODS

Fetal tracheas were divided into developmental phases: early, mid, and late. Fetal tracheas were xenografted onto immunocompromised mice and analyzed for SMG developmental staging and mucopolysaccharide production.

RESULTS

There were no significant differences in gland number, size, or density from early through late phase between groups. Xenografted tracheas demonstrated a similar progression through the stages of SMG development as controls after an initial phase shift. Control and xenografted tracheas demonstrated characteristic patterns of acidic mucin production at the base of the SMGs.

CONCLUSIONS

Fetal trachea xenograft SMG recapitulates normal development and is a valid model for studying human fetal gene transfer. The accessibility of SMG stem cells in early tracheal development may afford a unique window of opportunity for gene transfer. This model has the benefit of providing access to human fetal tracheas in vivo and permits the study of novel fetal gene therapy strategies.

Crohn's disease limited to the appendix: a case report in a pediatric patient

In the original description of Crohn's disease, the appendix was not believed to be involved in the inflammatory process. Later on, case reports started to appear in publications demonstrating that the appendix could be involved in the inflammatory changes of Crohn's disease, and it could also be the primary or the sole manifestation of the disease. Being that appendectomies are one of the most common procedures performed by pediatric surgeons, the knowledge about this diagnosis, all be it rare, is important. Our aim was to report a case and discuss the results of our literature review in order to elucidate the probability of a pediatric patient subsequently developing full Crohn's disease and the follow up that is indicated in such patients. A 12-year-old male patient presented with a history of chronic abdominal pain (3-4 times per week) for 1 year, crampy in nature, localized in the left lower quadrant, and associated with diarrhea (2 episodes per day). There were no extraintestinal manifestations of Crohn's, such as arthralgia or uveitis. Important family history included two paternal uncles with ulcerative colitis both of whom currently have stomas. The only abnormal laboratory value in our patient was an elevated fecal calprotectin level. An esophagogastroduodenoscopy and colonoscopy were performed and found to be unremarkable except for the cecum where it appeared that an exudate was emanating from the appendiceal orifice. A magnetic resonance enterography was ordered and showed an enlarged enhancing appendix. An exploratory laparoscopy identified an appendix with macroscopic cobblestone or lymphoid reaction that histologically was consistent with Crohn's disease. It appears that the Crohn's appendix is more indolent than Crohn's disease of the ileum or colon, with a recurrence rate in the largest series of 8%. The interval time from diagnosis to recurrence varied from 1 to 48 months with an average of 19 months. Some authors debate the need of follow up at all in those patients, believing that the appendectomy alone is curative in the majority of patients. Others recommend follow up for up to 5 years.

The transanal approach with laparoscopy or laparotomy for the treatment of rectal strictures in Crohn's disease

INTRODUCTION

Rectal strictures in patients with Crohn's colitis are common and options described for their treatment include direct steroid injection, injection of tumor necrosis factor (TNF) inhibitors, endoscopic balloon dilatation, use of Hegar dilators, stricturoplasty, and proctectomy. Adequate treatment is a challenge, especially with respect to the prevention of stricture recurrence. We present an option for the surgical treatment of these strictures using a transanal resection of the rectum with the addition of laparoscopy or laparotomy.

METHODS

Three patients who had medically refractory or chronic Crohn's colitis with rectal strictures were referred to us after failed medical management, rectal dilation, and balloon dilation of the strictures. In each case, we performed a transanal sphincter preserving dissection in the prone position and used the lithotomy position for intraabdominal mobilization, completion of the rectosigmoid resection, pull-through of the left colon, and coloanal anastomosis.

RESULTS

We resected the rectal strictures transanally in all three cases. One case provided the opportunity to perform a laparoscopy-assisted procedure, whereas the other 2 patients had laparotomy-assisted rectosigmoid resections. We did a coloanal anastomosis in 2 patients with healthy left colon. In the third case, the anal canal was preserved, but the patient was left with a stoma.

CONCLUSIONS

Transanal resection is feasible in the surgical treatment of rectal strictures in patients with Crohn's colitis. It preserves the anal sphincteric mechanism and may help in avoiding a permanent stoma in a subgroup of patients. We found the prone position very helpful in performing the transanal rectal dissection.

Button-loop feeding jejunostomy

INTRODUCTION

Post-pyloric feeding via a surgical jejunostomy allows for enteral nutrition in patients that cannot receive oral or gastric feeding. Regardless of the technique used to create a jejunostomy, complications such as tube dislodgement, jejunostomy closure, or bowel obstruction can occur.

SURGICAL TECHNIQUE

We present a simple and efficient jejunostomy technique that does not require a sewn anastomosis and employs an easily exchangeable feeding button.

Gastric tube-pericardial fistula: a remote complication of esophageal replacement for long gap esophageal atresia

Several short and long-term complications of esophageal replacement have been described in the literature. We report the case of a gastric tube-pericardial fistula occurring 20 years after initial repair of long gap esophageal atresia with a reversed gastric tube.

Extracorporeal membrane oxygenation in pediatric cardiac transplantation

BACKGROUND

We reviewed a single institution experience with extracorporeal membrane oxygenation (ECMO) in the perioperative management of cardiac transplantation.

METHODS

Of all pediatric cardiac transplant candidates (1984-2003), patients requiring ECMO pretransplantation/posttransplantation were identified, with particular attention to use of ECMO as a bridge to transplantation. Parameters reviewed included proportionate survival, incidence of pre-ECMO cardiac arrest, ECMO duration, and United Network for Organ Sharing list time.

RESULTS

Three hundred patients were listed for transplantation. Twenty-nine required ECMO: 18 pretransplant, 3 pretransplant and posttransplant, 6 posttransplant, and 2 for delayed acute rejection. There were 21 bridge-to-transplant candidates, of which 10 eventually transplanted with 60% survival; 11 not transplanted had no survivors (P = .004). Thirteen of 21 had cardiac arrest pre-ECMO with 1 (8%) survivor; 8 of 21 had no arrest with 5 (63%) survivors (P = .014). Mean ECMO duration and United Network for Organ Sharing list times between transplanted and not transplanted were not significant. Nine received ECMO posttransplantation for cardiopulmonary support; 5 (56%) of 9 survived. Two patients supported with ECMO for rejection-related cardiovascular collapse survived.

CONCLUSION

ECMO can bridge children to cardiac transplantation. Survival is significantly impaired in bridge-to-transplant candidates stratified by pre-ECMO cardiac arrest. ECMO can also help transition from cardiopulmonary bypass after transplantation and provide effective support during acute rejection.

Effects of potent VEGF blockade on experimental Wilms tumor and its persisting vasculature

We characterized the effect of potent vascular endothelial growth factor (VEGF) blockade on early-stage Wilms tumor xenograft growth, vasculature and metastasis. VEGF is a key mediator of both physiologic and tumor angiogenesis. We recently described that potent VEGF blockade induces regression of established Wilms tumor xenografts and vessels, also reducing the size but not the incidence of pre-existing metastases. In these studies, we examined the effects of potent VEGF blockade on earlier stages of experimental Wilms tumors, focusing on tumor growth, vasculature and metastasis. Athymic mice received intrarenal human Wilms tumor cell implants. Biweekly treatment with vehicle or the VEGF-Trap, a high-affinity soluble decoy receptor incorporating regions of VEGFR1 and VEGFR2, was begun 1 week later (100 or 500 micrograms/dose, n=20 in each group). Mice were euthanized at week 6 to examine tumor weight, incidence of lung metastases, vascularity and expression of angiogenic factors. A cohort of mice was examined 2 weeks after cessation of treatment. Compared to controls, VEGF-Trap treated tumors were significantly smaller (100 micrograms/dose: 92.7% smaller, p=0.0017; 500 micro g/dose: 99.0% smaller, p=0.0009). The incidence of lung metastasis also decreased significantly (p<0.0055). VEGF-Trap nearly eradicated tumor vasculature. Rare persisting vessels were characterized by large caliber, quiescence (lacking proliferation/apoptosis) and arterialization (both phenotypic and molecular). Potent VEGF blockade caused near-arrest of experimental Wilms tumor growth, resulted in nearly avascular tumors, and also decreased the incidence and size of metastases. Persistent vessels in tumors treated with VEGF-Trap displayed specific morphologic and molecular features, suggestive of arterialization. Future strategies that target these persisting vessels may enhance the efficacy of VEGF blockade therapy.

TNP-470 promotes initial vascular sprouting in xenograft tumors

TNP-470 (AGM-1470), an analogue of fumagillin, was one of the first molecules proposed to have antiangiogenic properties. This concept was based on its ability to inhibit both endothelial proliferation in vitro and tumor growth in vivo in a number of xenograft models. Yet, subsequent investigations indicated that the biochemical activities associated with TNP-470 are not selective for endothelial cells. Moreover, recent evidence suggests that this agent inhibits tumor growth in vivo, but without a corresponding decrease in angiogenesis. Therefore, we performed a detailed comparison of TNP-470 to a validated antiangiogenic agent, a VEGF inhibitor termed VEGF-Trap, using a xenograft model of Wilms tumor. Treatment with TNP-470 for 5 weeks significantly suppressed xenograft growth (83%). Surprisingly, this inhibition was not associated with a decrease in angiogenesis, but instead with an increase in tiny neovessels. To determine whether this was a direct effect of TNP-470 on tumor vessels, we examined its effect in a short-term assay using large tumors with established vasculature. In contrast to treatment with VEGF-Trap, which led to rapid vessel regression and tumor hypoxia, tumors exposed to TNP-470 for 1 day displayed increased capillary sprouting, with significantly increased microvessel density, vessel length, and branch points. TNP-470 did not induce tumor hypoxia as demonstrated by minimal pimonidazole staining and VEGF expression. TNP-470 did, however, cause a marked increase in apoptosis of tumor cells. Our results indicate that the antitumor effects of TNP-470 cannot be attributed to prevention of neoangiogenesis, but instead to its direct action on tumor cells.

Biomolecular markers and involution of hemangiomas

BACKGROUND/PURPOSE

Vascular anomalies are a diverse set of lesions with distinct clinical behaviors, whose biomolecular characteristics are largely undefined. Common hemangiomas proliferate during the first year of life, then involute at a variable pace over several years. Other vascular tumors may involute much more quickly (rapidly involuting congenital hemangiomas [RICH]), not at all (lymphatic malformation), or display malignant behavior (angiosarcoma). Key cytokines driving angiogenesis include vascular endothelial growth factor (VEGF) family members/receptors (placental growth factor [PIGF], VEGF-A, and VEGF-C) and angiopoietins. The authors hypothesized that involuting hemangiomas would display biologic markers distinctly different from noninvoluting vascular lesions.

METHODS

Six patient samples were analyzed: (1) RICH, (2) proliferating hemangioma, (3) involuting hemangioma, (4) tufted angioma, (5) hepatic angiosarcoma, and (6) lymphatic malformation. Detailed examination of endothelial/vascular mural cell status was performed by fluorescent double-label immunostaining using specific markers (PECAM-1, alphaSMA) in combination with markers of proliferation (anti-phospho-histone H3) or apoptosis (TUNEL). Expression of PIGF, VEGF-A, VEGF-C, and Ang-1 was localized by in situ hybridization.

RESULTS

Involuting/proliferating common hemangiomas demonstrated vasculature with abundant vascular mural cells (alphaSMA+); in contrast, alphaSMA(+) cells were rare in RICH vessels. Endothelial apoptosis was increased dramatically, but proliferation was unchanged during involution. VEGF-A was expressed in all lesions except lymphatic malformation, which displayed VEGF-C and Ang-1 upregulation. Strikingly, PIGF expression was increased markedly in the lesions predicted to involute/actively involuting but was virtually absent from noninvoluting tumors.

CONCLUSIONS

Vessel architecture and endothelial/vascular mural cell status differed between lesions, differentiating even common versus rapidly involuting hemangioma and corresponded to clinical involution. VEGF-A expression characterized endothelial-derived lesions, whereas VEGF-C marked lymphatic-derived cells. PIGF expression occurred only in vascular anomalies predicted to involute or actively involuting, a pattern potentially linked to PIGF function as a conditional antagonist of VEGF-A. Thus, distinct patterns of morphology and angiogenic factor expression characterize vascular anomalies with different clinical behaviors.

TNP-470 promotes initial vascular sprouting in xenograft tumors

TNP-470 (AGM-1470), an analogue of fumagillin, was one of the first molecules proposed to have antiangiogenic properties. This concept was based on its ability to inhibit both endothelial proliferation in vitro and tumor growth in vivo in a number of xenograft models. Yet, subsequent investigations indicated that the biochemical activities associated with TNP-470 are not selective for endothelial cells. Moreover, recent evidence suggests that this agent inhibits tumor growth in vivo, but without a corresponding decrease in angiogenesis. Therefore, we performed a detailed comparison of TNP-470 to a validated antiangiogenic agent, a VEGF inhibitor termed VEGF-Trap, using a xenograft model of Wilms tumor. Treatment with TNP-470 for 5 weeks significantly suppressed xenograft growth (83%). Surprisingly, this inhibition was not associated with a decrease in angiogenesis, but instead with an increase in tiny neovessels. To determine whether this was a direct effect of TNP-470 on tumor vessels, we examined its effect in a short-term assay using large tumors with established vasculature. In contrast to treatment with VEGF-Trap, which led to rapid vessel regression and tumor hypoxia, tumors exposed to TNP-470 for 1 day displayed increased capillary sprouting, with significantly increased microvessel density, vessel length, and branch points. TNP-470 did not induce tumor hypoxia as demonstrated by minimal pimonidazole staining and VEGF expression. TNP-470 did, however, cause a marked increase in apoptosis of tumor cells. Our results indicate that the antitumor effects of TNP-470 cannot be attributed to prevention of neoangiogenesis, but instead to its direct action on tumor cells.

Thalidomide is anti-angiogenic in a xenograft model of neuroblastoma

Thalidomide has previously been shown to have anti-angiogenic properties. More recently, clinical efficacy of this agent has been demonstrated in multiple myeloma and prostate cancer. Neuroblastoma is the most frequent solid tumor of the abdomen of childhood, yet children with this disease frequently have metastases at presentation. Such patients have a very poor prognosis with current therapies. Thus, new approaches are needed. We have previously shown that VEGF antagonists can inhibit neoangiogenesis and tumor growth in experimental neuroblastoma. In this study, we investigated the anti-angiogenic and anti-tumor properties of thalidomide in a xenograft model of human neuroblastoma. Tumors were induced in athymic mice using the human neuroblastoma cell line NGP. Intraperitoneal thalidomide (100 mg/kg/dose) or vehicle was administered beginning one week after implantation, and animals euthanized at six weeks. Thalidomide treatment did not significantly alter tumor growth as compared with controls. However, thalidomide suppressed angiogenesis, as demonstrated both by fluorescein angiography and immunohistochemical staining, and induced apoptosis of endothelial cells in neuroblastoma xenografts. Quantification of microvessel density demonstrated a significant reduction of vasculature in treated tumors (p<0.004). Thalidomide induced co-option of host vasculature, an effect noted previously after VEGF blockade. This study demonstrates that thalidomide has anti-angiogenic properties in experimental neuroblastoma.

Human epidermal growth factor receptor signaling contributes to tumor growth via angiogenesis in her2/neu-expressing experimental Wilms' tumor

BACKGROUND

The human epidermal growth factor family (HER) members play a significant role in the mesenchymal-to-epithelial transition during renal tubulogenesis. HER misexpression has been linked also to loss of growth control, invasiveness, and promotion of angiogenesis in breast cancers and other human malignant tumors

METHODS

The authors screened Wilms' tumor samples and derived cell lines for expression of her2/neu, which was detected in both unfavorable and favorable histology tissues. Xenografts were implanted in mice using her2/neu(+) and her2/neu(-) cell lines and the effect of specific blockade tested using monoclonal anti-her2/neu antibody.

RESULTS

Blocking antibody suppressed tumor growth in her2/neu(+) but not her2/neu(-) experimental Wilms' tumor. In addition, antibody exposure resulted in suppression of tumor angiogenesis but no decrease in tumor cell proliferation in her2/neu(+) xenografts.

CONCLUSIONS

Her2/neu contributes to the growth of some Wilms' tumors, and an important mechanism of its action is promotion of angiogenesis.

Blockade of her2/neu decreases VEGF expression but does not alter HIF-1 distribution in experimental Wilms tumor

Her2/neu regulates angiogenesis in human breast cancer, in part by stabilizing hypoxia-inducible factor 1alpha (HIF-1alpha), causing accumulation of the HIF-1 heterodimer and thus increasing expression of the proangiogenic cytokine VEGF. Her2/neu has recently been shown to be overexpressed in a subset of Wilms tumors. Using her2/neu (+) and her2/neu (-) Wilms tumor cell lines, we tested the effect of blocking anti-her2/neu antibody in vitro and in vivo. Blocking antibody did not alter VEGF expression in vitro, but decreased expression of VEGF in her2/neu (+) Wilms tumor xenografts. Tumor suppression was less marked than in parallel experiments using agents directly blocking VEGF. HIF-1alpha immunostaining was not altered in her2/neu (+) xenografts exposed to blocking antibody. These results suggest that her2/neu contributes to Wilms tumor angiogenesis in vivo by regulating VEGF, but other processes may act to rescue HIF-1alpha and thus to support tumor growth in this system.

Regression of established tumors and metastases by potent vascular endothelial growth factor blockade

Vascular endothelial growth factor (VEGF) is a critical promoter of blood vessel growth during embryonic development and tumorigenesis. To date, studies of VEGF antagonists have primarily focused on halting progression in models of minimal residual cancer. Consistent with this focus, recent clinical trials suggest that blockade of VEGF may impede cancer progression, presumably by preventing neoangiogenesis. However, VEGF is also a key mediator of endothelial-vascular mural cell interactions, a role that may contribute to the integrity of mature vessels in advanced tumors. Here, we report that high-affinity blockade of VEGF, using the recently described VEGF-Trap, abolishes mature, preexisting vasculature in established xenografts. Eradication of vasculature is followed by marked tumor regression, including regression of lung micrometastases. Thus, the contribution of relatively low levels of VEGF to vessel integrity may be critical to maintenance of even very small tumor masses. Potent blockade of VEGF may provide a new therapeutic option for patients with bulky, metastatic cancers.

Potent VEGF blockade causes regression of coopted vessels in a model of neuroblastoma

Vascular endothelial growth factor (VEGF) plays a key role in human tumor angiogenesis. We compared the effects of inhibitors of VEGF with different specificities in a xenograft model of neuroblastoma. Cultured human neuroblastoma NGP-GFP cells were implanted intrarenally in nude mice. Three anti-VEGF agents were tested: an anti-human VEGF(165) RNA-based fluoropyrimidine aptamer; a monoclonal anti-human VEGF antibody; and VEGF-Trap, a composite decoy receptor based on VEGFR-1 and VEGFR-2 fused to an Fc segment of IgG1. A wide range of efficacy was observed, with high-dose VEGF-Trap causing the greatest inhibition of tumor growth (81% compared with controls). We examined tumor angiogenesis and found that early in tumor formation, cooption of host vasculature occurs. We postulate that this coopted vasculature serves as a source of blood supply during the initial phase of tumor growth. Subsequently, control tumors undergo vigorous growth and remodeling of vascular networks, which results in disappearance of the coopted vessels. However, if VEGF function is blocked, cooption of host vessels may persist. Persistent cooption, therefore, may represent a novel mechanism by which neuroblastoma can partly evade antiangiogenic therapy and may explain why experimental neuroblastoma is less susceptible to VEGF blockade than a parallel model of Wilms tumor. However, more effective VEGF blockade, as achieved by high doses of VEGF-Trap, can lead to regression of coopted vascular structures. These results demonstrate that cooption of host vasculature is an early event in tumor formation, and that persistence of this effect is related to the degree of blockade of VEGF activity.

Long-term results with multimodal adjuvant therapy and liver transplantation for the treatment of hepatocellular carcinomas larger than 5 centimeters

OBJECTIVE

To determine the long-term results of liver transplantation for hepatocellular carcinoma (HCC) measuring 5 cm or larger treated in a multimodality adjuvant protocol.

SUMMARY BACKGROUND DATA

Transplant has been established as a viable treatment of HCC measuring less than 5 cm, but the results for larger tumors have been disappointing. Several studies have shown promising preliminary results when combining transplant with preoperative transarterial chemoembolization and/or perioperative systemic chemotherapy in the treatment of advanced HCC that is not amenable to resection. However, follow-up in the studies has been limited and the number of patients has been small.

METHODS

Beginning in October 1991, all patients with unresectable HCC measuring 5 cm or larger, as measured by computed tomography, were considered for enrollment in the authors' multimodality protocol. Entry criteria required that all patients be free of extrahepatic disease based on computed tomography scans of the chest and abdomen and bone scan and have a patent main portal vein and major hepatic veins on duplex ultrasonography. Patients received subselective arterial chemoembolization with mitomycin C, doxorubicin, and cisplatin at the time of diagnosis, repeated as necessary based on tumor response. Patients received a single systemic intraoperative dose of doxorubicin (10 mg/m(2)) before revascularization of the new liver and systemic doxorubicin (50 mg/m(2)) every 3 weeks as tolerated, for a total of six cycles, beginning on the sixth postoperative week.

RESULTS

Eighty patients were enrolled; 37 were eventually excluded, due mainly to disease progression while on the waiting list, and 43 underwent liver transplant. Mean pathologic tumor diameter was 5.8 +/- 2.7 cm. Median follow-up of surviving transplanted patients was 55.1 +/- 24.9 months. There were two (4.7%) perioperative deaths. Median overall survival was significantly longer in transplanted patients (49.9 +/- 10.42 months) than in those who were excluded (6.83 +/- 1.34 months). Overall and recurrence-free survival rates in transplanted patients at 5 years were 44% and 48%, respectively. A tumor size larger than 7 cm and the presence of vascular invasion correlated significantly with recurrence. Recurrence-free survival at 5 years was significantly higher for the 32 patients with tumors measuring 5 to 7 cm (55%) than the 12 patients with tumors larger than 7 cm (34%).

CONCLUSIONS

A significant proportion of patients with HCC measuring 5 cm or larger can achieve long-term survival after liver transplantation in the context of multimodal adjuvant therapy. Patients with tumors measuring 5 to 7 cm have significantly longer recurrence-free survival compared with those with larger tumors.