Gustavo A. Villalona

Tissue-engineered vascular grafts: does cell seeding matter?

PURPOSE Use of tissue-engineered vascular grafts (TEVGs) in the repair of congenital heart defects provides growth and remodeling potential. Little is known about the mechanisms involved in neovessel formation. We sought to define the role of seeded monocytes derived from bone marrow mononuclear cells (BM-MNCs) on neovessel formation. METHODS Small diameter biodegradable tubular scaffolds were constructed. Scaffolds were seeded with the entire population of BM-MNC (n = 15), BM-MNC excluding monocytes (n = 15), or only monocytes (n = 15) and implanted as infrarenal inferior vena cava (IVC) interposition grafts into severe combined immunodeficiency/bg mice. Grafts were evaluated at 1 week, 10 weeks, or 6 months via ultrasonography and microcomputed tomography, as well as by histologic and immunohistochemical techniques. RESULTS All grafts remained patent without stenosis or aneurysm formation. Neovessels contained a luminal endothelial lining surrounded by concentric smooth muscle cell layer and collagen similar to that seen in the native mouse IVC. Graft diameters differed significantly between those scaffolds seeded with only monocytes (1.022 +/- 0.155 mm) and those seeded without monocytes (0.771 +/- 0.121 mm; P = .021) at 6 months. CONCLUSIONS Monocytes may play a role in maintaining graft patency. Incorporation of such findings into the development of second-generation TEVGs will promote graft patency and success.

Modified Laparoscopic Gastrostomy Technique Reduces Gastrostomy Tract Dehiscence

PURPOSE To describe a modification in the Georgeson technique for laparoscopic gastrostomy tube (LGT) placement and compare the rate of reoperation for disruption of the gastrostomy tract after LGT by our modified technique to our own series of percutaneous endoscopic gastrostomy (PEG) tubes as well as the published rates of reoperation for LGTs and PEGs. METHODS In 2003, we modified our technique for LGT to include laparoscopically placed sutures to secure the stomach to the abdominal wall. A retrospective review was performed on all children undergoing LGT placement and PEGs from March 2003 to October 2009. In addition, a review of the literature was performed to identify the published rates of complications for these procedures. RESULTS During this time period, we have performed 85 LGT using this modified technique. In that same period, there have been 34 PEGs placed. The modification in our technique was instituted after a patient required reoperation for dislodgement in a laparoscopic U-stitch gastrostomy. To date, in the modified LGT group, there have been no disruptions of the gastrostomy tract in either the early or late periods, <90 days or >90 days, respectively. There have been 5 (5.9%) early dislodgements of the gastrostomy tube. All of these were before postoperative day 14 (at postoperative days 1, 2, 6, and 12), and all were replaced with placement verified by contrast study. None required reoperation. In the PEG group, there was 1 (2.9%) early and 1 (2.9%) late dislodgements and tract disruption that required reoperation. The published rate of dislodgement requiring reoperation in the Georgeson series of LGTs is 2.6%. The published rate of reoperation for dislodgement in PEGs is 4%-6%. CONCLUSION This modification of the Georgeson technique has been successful in reducing the need for reoperation associated with gastrostomy replacement after dislodgement.

Congenital and acquired mesocolic hernias presenting with small bowel obstruction in childhood and adolescence

OBJECTIVE The objective was to present a case series of pediatric patients presenting with small bowel obstruction secondary to both congenital and acquired internal mesocolic hernias, and the use of imaging technology in the management of this condition. METHODS A retrospective review of patients treated at the Yale-New Haven Childrens Hospital for small bowel obstruction from 1998 to 2008 (n = 6) who presented with acute small bowel obstruction secondary to internal mesocolic hernias was performed. RESULTS We present 6 patients with small bowel obstruction caused by congenital (n = 4) and acquired (n = 2) mesocolic hernias after previous surgery. The median age at presentation was 13 years. Small bowel obstruction with a mesocolic hernia was identified by preoperative abdominal computerized tomography in 3 patients (50%) and at operation in the others. The mean length of stay was 6 days, with no recurrent episodes in the follow-up period. CONCLUSION Small bowel obstruction secondary to mesocolic hernias, although rare, may be considered in the differential diagnosis of patients with history of malrotation or abdominal wall defects owing to their association with congenital mesenteric anomalies. This condition requires special attention from the clinician because of its catastrophic consequences. Imaging studies are an important asset because of the difficulty in making an accurate clinical diagnosis and the rarity of internal hernias.

Duodenal intussusception secondary to web presenting as recurrent pancreatitis in a 7-year-old girl

Duodenal intussusception is a rare entity in children, with 32 cases reported in the English literature to our knowledge. Most reported cases are associated with endoluminal tubes or polyps, and the presenting symptoms are chronic and nonspecific. We report a case of duodenal intussusception in a 7-year-old girl secondary to a duodenal web and review the imaging findings.