Robotic-assisted laparoscopic Malone appendicostomy: a 6-year perspective.

PURPOSE: A robotic-assisted laparoscopic approach to appendicostomy offers the benefits of a minimally invasive approach to patients who would typically necessitate an open procedure, those with a larger body habitus, and those requiring combined complex colorectal and urologic reconstructive procedures. We present our experience performing robotic-assisted appendicostomies with a focus on patient selection, perioperative factors, and functional outcomes. METHODS: A retrospective review of patients who underwent a robotic-assisted appendicostomy/neoappendicostomy at our institution was performed. RESULTS: Twelve patients underwent robotic-assisted appendicostomy (n = 8) and neoappendicostomy (n = 4) at a range of 8.8-25.8 years. Five patients had a weight percentile > 50% for their age. Seven patients underwent combined procedures. Median operative time for appendicostomy/neoappendicostomy only was 185.0 min. Complications included surgical site infection (n = 3), stricture requiring minor operative revision (n = 2), conversion to an open procedure due to inadequate appendiceal length (prior to developing our technique for robotic neoappendicostomies; n = 1), and granuloma (n = 1). At a median follow-up of 10.8 months (range 1.7-74.3 months), 91.7% of patients were consistently clean with antegrade enemas. DISCUSSION: Robotic-assisted laparoscopic appendicostomy and neoappendicostomy with cecal flap is a safe and effective operative approach. A robotic approach can potentially overcome the technical difficulties encountered in obese patients and can aid in patients requiring both a Malone and a Mitrofanoff in a single, combined minimally invasive procedure.

Outcomes From Colonic Pull-Through for Cloacal Exstrophy Differ by Colon Length: A Multi-Institutional Study.

BACKGROUND: Cloacal exstrophy (CE) represents a rare sub-group of anorectal malformations. Traditionally managed with a permanent colostomy, colonic pull-through (PT) has emerged to allow cleanliness without a life-long stoma. We sought to understand outcomes of PT in a large multi-center CE population. METHODS: We performed a retrospective study involving eleven pediatric hospitals. We gathered data on demographics, outcomes, and anatomical factors including colon length. Continuous variables were analyzed with Wilcoxon rank-sum tests and categorial variables with Fisher's exact tests. RESULTS: There were 98 patients, of which the majority (n = 70, 71.4 %) never underwent PT. There were no differences in exstrophy type, demographics, or associated anomalies. Median age at PT was 1.3 years (IQR 0.3-3.7). Of the cohort that continue to use their PT, the majority (n = 16, 69.6 %) are not clean. In total, 7.1 % (n = 7) of the cohort is clean with a PT, and only one patient is continent. Clean patients have a longer colon length than those who are not clean or opt for re-do ostomy (64.0 cm [IQR 46.0-82.0] vs 26.5 cm [IQR 11.6-41.2], p = 0.005). CONCLUSION: Overall, we demonstrate that most children born with CE will keep their stoma. Only a small percentage who elect to undergo colonic PT are clean for stool. Greater colon length correlates with success. This suggests that multiple factors, including colon length, are important when considering PT in a child with CE. LEVEL OF EVIDENCE: III.

Late Diagnosis of Hirschsprung Disease: Clinical Presentation and Long-Term Functional Outcomes.

PURPOSE: Hirschsprung Disease (HD) is typically diagnosed in the neonatal period. A small subset of patients have a prolonged course of abdominal distention and constipation prior to diagnosis. Late HD is defined as having been diagnosed at greater than or equal to one year of age. The literature is limited and offers conflicting data on the implications of a late diagnosis. We aim to investigate the presentation, operative approach, and functional outcomes of a large cohort of patients with a late HD diagnosis. METHODS: All patients with a late diagnosis of HD (after 1 year of age) at our institution between 1997 and 2021 were included. RESULTS: Twenty-eight patients were diagnosed with HD at a median age of 3.4 years. Chronic constipation, failure to thrive, and enterocolitis occurred in 100 %, 31 %, and 14 %, respectively. All patients underwent contrast enema and biopsies during their workup, identifying primarily rectosigmoid disease (n = 27) and total colonic aganglionosis (n = 1). Surgical intervention was performed in 27 patients, with 4 patients (15 %) needing a stoma (3 with plan for staged pull-through, 1 long-term stoma) and 23 patients (85 %) undergoing a single-stage pull-through. Postoperative complications included Hirschsprung-associated enterocolitis (n = 5), ostomy prolapse and revision (n = 2), abdominal distention requiring ileostomy creation (n = 2), redo pull-through (n = 2), retroperitoneal hematoma (n = 1), and cecostomy tube placement (n = 1). At a median follow-up of 5.4 years, 83 % of eligible patients achieved fecal continence with 43 % needing laxatives for persistent constipation. CONCLUSION: Recognizing a late presentation of HD requires a high index of suspicion. Patients with a late diagnosis did not experience an increased rate of permanent stoma, complications, or redo surgery compared to rates reported for the larger HD population. Similar long-term functional outcomes were achieved compared to the larger HD population. LEVEL OF EVIDENCE: IV.

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.

Surgical Resection of Vulvar Labial Venous Malformations: A Single Center Experience.

BACKGROUND: Venous malformations (VMs) involving the vulva are rare but often cause debilitating pain, aesthetic concern, and functional impairment. Treatment with medical therapy, sclerotherapy, operative resection, or a combination thereof may be considered. The optimal therapeutic approach remains unclear. We report our experience resecting labial VMs in a large cohort of patients. METHODS: A retrospective review of patients who underwent partial or complete resection of a labial VM was conducted. RESULTS: Thirty-one patients underwent forty-three resections of vulvar VMs between 1998 and 2022. Physical examination and imaging demonstrated: 16% of patients had focal labial lesions, 6% had multifocal labial lesions, and 77% had extensive labial lesions. Indications for intervention included pain (83%), appearance (21%), functional impairment (17%), bleeding (10%), and cellulitis (7%). Sixty-one percent of patients underwent a single resection, 13% multiple partial resections, and 26% a combination of sclerotherapy and operative resection(s). Median age was 16.3 years at first operation. All patients requiring multiple operations had extensive VMs. Median blood loss was 200 mL. Postoperative complications included wound infection/dehiscence (14%), hematoma (2%), and urinary tract infection (2%). The median follow-up assessment was 14 months: 88% of patients had no complaints and 3 patients were experiencing recurrent discomfort. CONCLUSIONS: Surgical resection is a safe and effective approach to treating vulvar labial VMs. Patients with focal or multifocal VMs can be successfully treated with a single resection, whereas patients with an extensive VM may require multiple partial resections or combined sclerotherapy and resection(s) to achieve long-term control. TYPE OF STUDY: Retrospective Study. LEVEL OF EVIDENCE: IV.

Primary and secondary vaginal reconstruction with autologous buccal mucosa and intravaginal wound vacuum therapy.

BACKGROUND: Vaginal reconstruction with autologous buccal mucosa graft offers a promising alternative to the use of skin grafts and vascularized intestinal segments. Given the novelty of this procedure, the optimal approach to postoperative wound management remains unclear with current practices often requiring many months of vaginal stents/molds. This study aims to evaluate a newly developed negative pressure intravaginal wound vacuum placed at the conclusion of the vaginoplasty with the goals of facilitating graft take and healing. METHODS: A retrospective review of patients (age 12-21 years) who underwent eight primary and secondary vaginoplasty procedures using autologous buccal mucosa coupled with intravaginal wound vacuum placement was performed. RESULTS: Vaginal reconstruction with fenestrated full-thickness buccal mucosa graft and intravaginal wound vacuum placement was successfully performed eight times in seven patients at a median age of 15.6 years. Four patients underwent robotic vaginal pull-through with buccal mucosa serving as an interposition graft, and four patients underwent vaginoplasty with buccal graft alone. All cases had excellent engraftment at time of wound vacuum removal on postoperative day seven and had healthy-appearing buccal mucosa at a mean follow-up of 148 days. Postoperatively, one patient developed a stricture at the anastomosis between native vagina and buccal mucosa graft, requiring a second buccal mucosa graft six months after the first operation. CONCLUSIONS: The use of autologous buccal mucosa graft for primary and secondary vaginal reconstruction coupled with intravaginal wound vacuum therapy offers a promising new approach. Negative pressure wound vacuum therapy may provide a more optimal wound healing environment for improved outcomes. TYPE OF STUDY: Retrospective Study LEVELS OF EVIDENCE: Level IV.

Hindgut Duplication in an Infant with Omphalocele-Exstrophy-Imperforate Anus-Spinal Defects (OEIS) Complex.

Introduction The congenital anomaly of omphalocele, cloacal exstrophy, imperforate anus, and spinal abnormalities (OEIS complex) is rare but well recognized. Hindgut duplications are also uncommon and are not known to be associated with OEIS. We describe a neonate with OEIS who was found to have fully duplicated blind-ending hindguts. Case Report A premature infant boy with OEIS underwent first-stage closure on day of life 6, which included excision of the omphalocele sac, separation of the cecal plate and bladder halves, tubularization of the cecal plate, hindgut rescue with end colostomy, and joining of the bladder halves. Cecal plate inspection revealed two hindgut structures that descended distally, one descended midline into the pelvis along the sacrum and the second laterally along the left border of the sacrum. Both lumens connected to the cecal plate and had separate mesenteries. In an effort to maximize the colonic mucosal surface area, the hindgut segments were unified through a side-to-side anastomosis, creating a larger caliber hindgut. The cecal plate was tubularized and an end colostomy was created. Bowel function returned and he was discharged home on full enteral feeds. Discussion This case represents a cooccurrence of two extremely rare and complex congenital anomalies. The decision to unify the distinct hindguts into a single lumen was made in an effort to combine the goals of management for both OEIS and alimentary duplications. The hindgut is abnormal in OEIS and should be assessed carefully during repair.

Urinary continence disparities in patients with anorectal malformations.

PURPOSE: While fecal incontinence is a primary concern for many children with anorectal malformations (ARM), urinary incontinence is also prevalent in this population. Racial, ethnic, and socioeconomic disparities in urinary continence have been observed in other conditions, but have not been previously evaluated in ARM. We aimed to evaluate urinary continence and associated demographic and socioeconomic characteristics in individuals with ARM. METHODS: We performed a multicenter retrospective study of ARM patients evaluated at sites participating in the Pediatric Colorectal and Pelvic Learning Consortium (PCPLC).  We included all patients with ARM 3 years and older. The primary outcome was urinary continence which was categorized as complete (no accidents), daytime (accidents at night), partial (rare or occasional accidents), and none (frequent accidents or no continence). We evaluated for associations between urinary continence and race, sex, age, insurance status, and adoption status, employing Kruskal-Wallis and trend tests. Secondary outcomes included bladder management strategies such as clean intermittent catheterization and continence surgery. P-value < 0.05 was considered significant. RESULTS: A total of 525 patients with ARM were included. Overall, 48% reported complete urinary continence, and continence was associated with greater age. For school-aged children (age ≥ 5 years), 58% reported complete continence, while 30% reported none. Public insurance and adoption status were associated with decreased likelihood of incontinence. CONCLUSIONS: We observed a novel finding of disparities in urinary continence for children with ARM related to insurance and adoption status. Further investigation regarding the etiologies of these inequities is needed in order to affect clinical outcomes.

Reoperative surgery in anorectal malformation patients.

Currently accepted primary repair of congenital anorectal malformations (ARMs) includes a posterior sagittal incision, which allows for optimal visualization and identification of important pelvic structures and anatomical features. Reconstructive surgery involves meticulous dissection and separation of pelvic structures, and careful reconstruction can result in good functional outcomes for many patients, who live without ongoing sequelae from their malformation. However, some patients may require reoperative procedures for anatomic or functional reasons. Males and females present with slightly different symptoms and should be approached differently. Males are most likely to require reoperations for anorectal or urethral pathologies, but the urinary system is often spared in females-they instead must contend with Mullerian duct anomalies, of which there are many varieties. Depending on the original malformation and severity of symptoms, redo surgery may be needed to optimize function and quality of life. Surgical management with reoperative surgery in ARMs ranges from straightforward to complex, depending on the issue. One must weigh the risks of reoperative surgery and potentially creating more scarring against the need for a better anatomical and functional outcome. Current management trends and practice patterns with regards to reoperative surgery in ARM patients are not widely studied or standardized but we provide an overview of the more common pathologies, preoperative evaluation and workup required to identify the issues, and options for reoperative repair in these patients.

Reoperative techniques and management in Hirschsprung disease: a narrative review.

The majority of children who undergo operative management for Hirschsprung disease have favorable results. A subset of patients, however, have long-term dysfunctional stooling, characterized by either frequent soiling or obstructive symptoms. The evaluation and management of a child with poor function after pull-through for Hirschsprung disease should be conducted by an experienced multidisciplinary team. A systematic workup is focused on detecting pathologic and anatomic causes of pull-through dysfunction. This includes an exam under anesthesia, pathologic confirmation including a repeat biopsy, and a contrast enema, with additional studies depending on the suspected etiology. Obstructive symptoms may be due to technique-specific types of mechanical obstruction, histopathologic obstruction, or dysmotility-each of which may benefit from reoperative surgery. The causes of soiling symptoms include loss of the dentate line and damage to the anal sphincter, which generally do not benefit from revision of the pull-through, and pseudo-incontinence, which may reveal underlying obstruction. A thorough understanding of the types of complications associated with various pull-through techniques aids in the evaluation of a child with postoperative dysfunction. Treatment is specifically tailored to the patient, guided by the etiology of the patient's symptoms, with options ranging from bowel management to redo pull-through procedure. This review details the workup and management of patients with complications after pull-through, with a focus on the perioperative management and technical considerations for those who require reoperation.

Can complex surgical interventions be standardized? Reaching international consensus on posterior sagittal anorectoplasty using a modified-Delphi method.

BACKGROUND/PURPOSE: In an effort to standardize educational experience, address future physician shortages, and improve quality of care to patients, many surgical specialties are discussing how to maximize exposure to index cases. One solution being explored is telementoring, which requires a well-developed educational curriculum with intraoperative objectives. The American College of Surgery Telementoring Task Force selected anorectal malformation and posterior sagittal anorectoplasty (PSARP) for the repair of imperforate anus as the initial educational focus for this pilot. The purpose of this study was to obtain international consensus on intraoperative learning objectives for a complex surgical procedure. METHODS: A multidisciplinary team of medical educators and pediatric surgery experts created an outline of essential curricular content and intraoperative learning objectives for PSARP in three clinical scenarios. Twelve international subject matter experts were identified meeting strict inclusion criteria. Intraoperative checklists were revised using the modified-Delphi process. RESULTS: After five rounds of modifications to the intraoperative checklists, international consensus was achieved for three different clinical scenarios requiring a PSARP: perineal or vestibular fistula, low prostatic fistula, and bladder neck fistula. CONCLUSIONS: A modified-Delphi approach was successful in generating guidelines for surgical techniques that can be used to standardize intraoperative teaching and expectations for trainees. TYPE OF STUDY: Diagnostic study LEVEL OF EVIDENCE: Level V (expert opinion).

Contrast enhanced colostography: New applications in preoperative evaluation of anorectal malformations.

INTRODUCTION: Understanding details of anatomic relationships between the colon and surrounding structures is a critical piece of preoperative planning prior to surgical repair of anorectal malformations (ARMs). Traditional imaging techniques involve ionizing radiation, distention of the rectum with supraphysiologic intraluminal pressures, and sometimes require sedation. Recent developments in the field of contrast agents have allowed the emergence of an ultrasound-based technique that can avoid these requirements while continuing to provide high resolution structural information in three dimensions. METHODS: Fourteen children (13 male, 1 female, age 1-11 months) with ARMs underwent contrast enhanced colostography (ceCS) in addition to traditional preoperative imaging techniques to delineate anatomic relationships of pelvic structures. RESULTS: ceCS and traditional imaging yielded concordant anatomic information, including structural relationships and fistulous connections, in 10/14 patients (71%). ceCS detected fistulous connection in 2/13 patients (15%) that were not seen by traditional imaging. Ultrasonography failed to detect the fistulous connection in one patient. CONCLUSIONS: ceCS is a safe, effective and flexible method for defining important structural information in ARM patients. When compared with traditional methods, it provided equivalent or superior results 93% of the time and bears consideration as a standard tool in preoperative planning for this population. TYPE OF STUDY: Retrospective Comparative Study. LEVEL OF EVIDENCE: Level III.

Safety of delayed surgical repair of omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex in infants with significant comorbidities.

PURPOSE: Management of infants with OEIS complex is challenging and not standardized. Expeditious surgery after birth has been recommended to limit soilage of the urinary tract and optimize intestinal function. However, clinical instability secondary to comorbidities is common in this population and early operation carries risk. We sought to define the risk/benefit profile of delaying repair. METHODS: All newborn patients with OEIS managed by our institution between Sep 2017 and Oct 2019 were reviewed. Comorbidities were evaluated, including cardiopulmonary pathologies and associated malformations. RESULTS: Ten patients with OEIS were managed. Patients underwent early (2 patients, repair at 0-2 days) or delayed (6 patients, repair at 6-87 days) first-stage exstrophy repair. Two patients died prior to repair (progressive respiratory failure, severe genetic anomalies). Repairs were delayed secondary to cardiac conditions, neurosurgical interventions, medical disease, and/or delayed transfer. Delayed repair patients had longer lengths of stay and use of parenteral nutrition. No patients experienced urinary tract infections prior to repair. CONCLUSIONS: Delaying first-stage exstrophy repair to allow physiologic optimization is safe. All repaired patients were discharged home, without parenteral nutrition or supplemental oxygen.

A New Approach to Cloaca: Laparoscopic Separation of the Urogenital Sinus.

Introduction: Cloaca malformation repair strategy is strongly dictated by common channel and urethral lengths. Mid to long common channel cloacas are challenging and often require laparotomy for dissection of pelvic structures. The balance of common channel and urethral lengths often dictates the approach for reconstruction. Laparoscopy has been utilized for rectal dissection but not for management of the urogenital (UG) structures. We hypothesized that laparoscopy could be applied to UG separation in reconstruction of cloaca malformations. Methods: Records were reviewed for 9 children with cloaca who underwent laparoscopic rectal mobilization and UG separation. Clinical parameters reviewed included demographics, relevant anatomic lengths, operative duration, transfusion requirements, and perioperative complications. Results: Repair was perfomed at a median (interquartile range) age of 12 (7, 15) months. Common channel length as measured by cystoscopy was 3.5 (3.3, 4.5) cm. There were no intraoperative complications. Transfusion requirements were minimal. Postoperative length of stay was 6 (5, 11) days. One patient developed a urethral web and 2 developed vaginal stenosis. One patient later underwent a laparotomy for obstruction due to a twisted rectal pull-through. Conclusions: Laparoscopic rectal mobilization and UG separation in long common channel cloaca are safe and well tolerated. Laparoscopy affords full evaluation of Mullerian structures and enables separation of the common UG wall, which may ultimately enhance long-term urinary continence.

Colorectal Vascular Anomalies.

Vascular anomalies represent a diverse group of tumors and malformations. Those involving the colon and rectum can greatly impact patients' quality of life. Proper workup to ensure the correct diagnosis can vary and may include endoscopic and radiographic studies. These lesions can also be challenging to treat and often require a multidisciplinary approach to ensure the best possible outcome. Treatment can include medical therapy, sclerotherapy, endoscopic, and operative intervention. Many patients will require multimodal therapy. We discuss the workup and management of vascular lesions of the colon and rectum.

Intramuscular fast-flow vascular anomaly contains somatic MAP2K1 and KRAS mutations.

BACKGROUND: The term "intramuscular hemangioma capillary type" (IHCT) refers to a fast-flow vascular lesion that is classified as a tumor, although its phenotype overlaps with arteriovenous malformation (AVM). The purpose of this study was to identify somatic mutations in IHCT. METHODS: Affected tissue specimens were obtained during a clinically indicated procedure. The diagnosis of IHCT was based on history, physical examination, imaging and histopathology. Because somatic mutations in cancer-associated genes can cause vascular malformations, we sequenced exons from 446 cancer-related genes in DNA from 7 IHCT specimens. We then performed mutation-specific droplet digital PCR (ddPCR) to independently test for the presence of a somatic mutation found by sequencing and to screen one additional IHCT sample. RESULTS: We detected somatic mutations in 6 of 8 IHCT specimens. Four specimens had a mutation in MAP2K1 (p.Q58_E62del, p.P105_I107delinsL, p.Q56P) and 2 specimens had mutations in KRAS (p.K5E and p.G12D, p.G12D and p.Q22R). Mutant allele frequencies detected by sequencing and confirmed by ddPCR ranged from 2 to 15%. CONCLUSIONS: IHCT lesions are phenotypically similar to AVMs and contain the same somatic MAP2K1 or KRAS mutations, suggesting that IHCT is on the AVM spectrum. We propose calling this lesion "intramuscular fast-flow vascular anomaly."

Contrast-Enhanced Colosonography for the Evaluation of Children With an Imperforate Anus.

This case series describes a novel method for showing the preoperative anatomy of children with anorectal malformations using ultrasound contrast, which we have termed "contrast-enhanced colosonography (ceCS)." Six patients with anorectal malformations without a perineal fistula were studied both by fluoroscopic distal colostography and ceCS, and their results were confirmed surgically. Contrast-enhanced CS precisely showed the complex anatomic relationships in all cases. Compared to traditional fluoroscopic studies, ceCS has the benefit of no associated ionizing radiation and thus is safer for children.

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.

Myeloid Wnt ligands are required for normal development of dermal lymphatic vasculature.

Resident tissue myeloid cells play a role in many aspects of physiology including development of the vascular systems. In the blood vasculature, myeloid cells use VEGFC to promote angiogenesis and can use Wnt ligands to control vascular branching and to promote vascular regression. Here we show that myeloid cells also regulate development of the dermal lymphatic vasculature using Wnt ligands. Using myeloid-specific deletion of the WNT transporter Wntless we show that myeloid Wnt ligands are active at two distinct stages of development of the dermal lymphatics. As lymphatic progenitors are emigrating from the cardinal vein and intersomitic vessels, myeloid Wnt ligands regulate both their numbers and migration distance. Later in lymphatic development, myeloid Wnt ligands regulate proliferation of lymphatic endothelial cells (LEC) and thus control lymphatic vessel caliber. Myeloid-specific deletion of WNT co-receptor Lrp5 or Wnt5a gain-of-function also produce elevated caliber in dermal lymphatic capillaries. These data thus suggest that myeloid cells produce Wnt ligands to regulate lymphatic development and use Wnt pathway co-receptors to regulate the balance of Wnt ligand activity during the macrophage-LEC interaction.

Long-term outcome for kaposiform hemangioendothelioma: A report of two cases.

Kaposiform hemangioendothelioma (KHE) is a rare aggressive vascular tumor of skin and deep soft tissues that typically presents in infancy and may be associated with a potentially life-threatening coagulopathy known as Kasabach-Merrit phenomenon (KMP). Recent advances in medical therapy have successfully treated many patients. However, our knowledge regarding the natural history of these lesions and optimum surveillance strategies remains rudimentary. We report two young women who had KHE with KMP treated in infancy and presented in adolescence with comorbidities related to their KHE tumor. This presentation supports the need for long-term surveillance in these patients.