Stephen Kim - Academia.edu (original) (raw)
Papers by Stephen Kim
The Journal of Trauma: Injury, Infection, and Critical Care, 2000
... Case Reports. Hemosuccus Pancreaticus after Penetrating Trauma to the Abdomen. Kim, Stephen S... more ... Case Reports. Hemosuccus Pancreaticus after Penetrating Trauma to the Abdomen. Kim, Stephen S. MD; Roberts, Roxanne R. MD; Nagy, Kimberly K. MD; Joseph, Kimberly MD; Bokhari, Faran MD; An, Gary MD; Barrett, John MD. ... 2000 Lippincott Williams & Wilkins, Inc. ...
Transplantation, 1998
Our laboratory is investigating the tissue engineering of small intestine using intestinal epithe... more Our laboratory is investigating the tissue engineering of small intestine using intestinal epithelial organoid units seeded onto highly porous biodegradable polymer tubes. This study investigated methods of stimulation for optimizing neointestinal regeneration. Intestinal epithelial organoid units harvested from neonatal Lewis rats were seeded onto porous biodegradable polymer tubes and implanted into the omentum of adult Lewis rats in the following groups: (1) the control group (group C), implantation alone (n=9); (2) the small bowel resection (SBr) group, after 75% SBr (n=9); (3) the portacaval shunt (PCS) group, after PCS (n=8); and (4) the partial hepatectomy (PH) group, after 75% PH (n=8). Neointestinal cyst size was recorded using ultrasonography. Constructs were harvested at 10 weeks and were examined using histology. Morphometric analysis of the neomucosa was obtained using a computer image analysis program (NIH Image, version 1.59). Cyst development was noted in all animals. Cyst lengths and diameters were significantly larger in the SBr group at 7 and 10 weeks compared with the other three groups (P<0.05; analysis of variance [ANOVA], Fisher's protected least significant difference). Histology revealed a well-vascularized tissue with a neomucosa lining the lumen with invaginations resembling crypt-villus structures. Morphometric analysis demonstrated a significantly greater villus number, height, area, and mucosal surface in the SBr group compared with the other three groups and a significantly greater crypt number and area in the PCS group compared with group C (P<0.05; ANOVA, Fisher's protected least significant difference). Intestinal epithelial organoid units transplanted on porous biodegradable polymer tubes can successfully vascularize, survive, and regenerate into complex tissue resembling small intestine. SBr and, to a lesser extent, PCS provide significant regenerative stimuli for the morphogenesis and differentiation of tissue-engineered small intestine.
Transplantation, 1999
Our laboratory has investigated the fabrication of a tissue-engineered intestine using biodegrada... more Our laboratory has investigated the fabrication of a tissue-engineered intestine using biodegradable polymer scaffolds. Previously we reported that isolated intestinal epithelial organoid units on biodegradable polymer scaffolds formed cysts and the neointestine was successfully anastomosed to the native small bowel. The purpose of this study was to observe the development of tissue-engineered intestine after anastomosis and to demonstrate the effect of the anastomosis over a 9-month period. Microporous biodegradable polymer tubes were created from polyglycolic acid. Intestinal epithelial organoid units were harvested from neonatal Lewis rats and seeded onto the polymers, which were implanted into the abdominal cavity of adult male Lewis rats followed by 75% small bowel resection (n=24). Three weeks after implantation, the unit/polymer constructs were anastomosed to the native jejunum in a side-to-side fashion. The anastomosed tissue-engineered intestine was measured by laparotomy 10, 24, and 36 weeks after the implantation (n= 14). During the laparotomy, all rats with an obstruction in their anastomosis were killed and excluded from the statistical analysis. Another five rats were also killed at 10 and 36 weeks for histological and morphometric studies. All analyzed rats survived this study and significantly increased their body weight by 36 weeks. Obstruction of the anastomosis was observed in one rat at 24 weeks and in two rats at 36 weeks; however, the anastomosis was patent in the other 11 rats by 36 weeks. The tissue-engineered intestine of these 11 rats increased in length and diameter at 10, 24, and 36 weeks after anastomosis; there were statistically significant differences between each time point except between the length of 10 and 24 weeks (P<0.016 by Wilcoxon signed rank test). Histologically the inner surface of the tissue-engineered intestine was lined with well-developed neomucosa at 10 and 36 weeks; however, there were small bare areas lacking neomucosa in the tissue-engineered intestine at 36 weeks. Morphometric analysis demonstrated no significant differences in villus number, villus height, and surface length of the neomucosa at 10 and 36 weeks. Anastomosis between tissue-engineered intestine and native small bowel resulted in no complications after operation and maintained a high patency rate for up to 36 weeks. The tissue-engineered intestine increased in size and was lined with well-developed neomucosa for the duration of the study.
Tissue Engineering, 1999
Background. Previous work from this laboratory has shown that isolated intestinal epithelial orga... more Background. Previous work from this laboratory has shown that isolated intestinal epithelial organoid units on porous biodegradable polymer scaffolds formed vascularized cysts lined by a neomucosa. The purpose of this study was to demonstrate anastomosis between tissue-engineered intestine and the native small bowel and to observe the effect of this anastomosis on cyst growth. Methods. Intestinal epithelial organoid units from neonatal Lewis rats were seeded onto porous biodegradable polymer tubes made of polyglycolic acid, and they were implanted into the omentum of adult male Lewis rats. Three weeks after implantation, the unitpolymer constructs were anastomosed in a side-to-side fashion to the native jejunum in 20 rats (group 1). The other 18 rats were closed without anastomosis (group 2). All 38 tissue-engineered constructs were harvested 10 weeks after implantation. Four rats underwent upper gastrointestinal (GI) study before they were killed. Results. The rats in group 1 increased their body weights equal to those in group 2, and there was no statistically significant difference between the two groups. Upper GI examinations revealed no evidence of either bowel stenosis or obstruction at the anastomotic site. Grossly, the patency of the anastomosis was 90% and the lumen of the cyst was visualized by the upper GI study. At the second operation, there was no significant difference in the size of the cysts in either group: however, at the time the rats were killed, the length of the cysts in group 1 was significantly longer than that in group 2 (P<0.05 using Mann-Whitney U test). Histological examination showed that cysts after anastomosis were lined by a neomucosa in continuity to native small bowel across the anastomotic site and also demonstrated crypt-villus structures. Morphometric study demonstrated that cysts in group 1 had significantly greater villus number, height, and surface length than did those in group 2. Conclusions. Anastomosis between tissue-engineered intestine and native small bowel resulted in no complications after the operation, kept a high patency rate, and maintained mucosal continuity between the tissue-engineered intestine and native small bowel. Furthermore, anastomosis had a positive effect on cyst size and development of the mucosa in the tissue-engineered intestine.
The American Journal of Surgery, 2008
The purpose of this study was to present 3 cases of left-sided gastroschisis and review the liter... more The purpose of this study was to present 3 cases of left-sided gastroschisis and review the literature concerning this rare condition. METHODS: Charts of 3 previously unreported patients with left-sided gastroschisis were reviewed. A literature review of all cases of left-sided gastroschisis was completed. RESULTS: Sixteen patients with left-sided defects were identified, only 12 of whom had classic periumbilical defects. We present 3 additional patients. Eleven of 15 patients were female, with 1 patient's sex not reported. Forty percent had extraintestinal anomalies. CONCLUSIONS: Left-sided gastroschisis is more common in females and associated with a higher incidence of extraintestinal anomalies compared with right-sided lesions. Although the etiology remains unknown, it may differ from that of right-sided gastroschisis.
The Journal of Trauma: Injury, Infection, and Critical Care, 2009
The Heimlich maneuver is a well-described emergency procedure for management of foreign body airw... more The Heimlich maneuver is a well-described emergency procedure for management of foreign body airway obstructions. Although rare, complications of the Heimlich maneuver do exist. The purpose of this report is to review the known complications of this procedure. All reported complications published in English on Medline and PubMed were reviewed. Additionally, we present a rare case of acute pancreatitis with associated pseudocyst formation after the administration of the Heimlich maneuver on a healthy 3-year-old boy. Although life saving, the Heimlich maneuver may be associated with significant complications; thus, symptomatic patients after this maneuver should be thoroughly evaluated with appropriate laboratory and radiographic studies.
Journal of Surgical Research, 1999
Our laboratory is investigating the tissue engineering of small intestine using intestinal epithe... more Our laboratory is investigating the tissue engineering of small intestine using intestinal epithelial organoid units seeded onto highly porous biodegradable polymer matrices. This study investigated the effects of anastomosis of tissue-engineered intestine to native small bowel alone or combined with small bowel resection on neointestinal regeneration. Intestinal epithelial organoid units harvested from neonatal Lewis rats were seeded onto biodegradable polymer tubes and implanted into the omentum of adult Lewis rats as follows: (1) implantation alone (n = 9); (2) implantation followed by anastomosis to native small bowel at 3 weeks (n = 11); and (3) implantation after small bowel resection and anastomosis to native small bowel at 3 weeks (n = 8). All constructs were harvested at 10 weeks and examined by histology. Morphometric analysis of the neomucosa was obtained using a computer image analysis program. Cyst development was noted in all animals. All anastomoses were patent at 10 weeks. Histology revealed the development of a vascularized tissue with a neomucosa lining the lumen of the cyst with invaginations resembling crypt-villus structures. Morphometric analysis demonstrated significantly greater villus number, villus height, crypt number, crypt area, and mucosal surface length in groups 2 and 3 compared with group 1, and significantly greater villus number, villus height, crypt area, and mucosal surface length in group 3 compared with group 2 (P < 0.05, ANOVA, Tukey test). Intestinal epithelial organoid units transplanted on biodegradable polymer tubes can regenerate into complex tissue resembling small intestine. Anastomosis to native small bowel combined with small bowel resection and anastomosis alone contribute significant regenerative stimuli for the morphogenesis and differentiation of tissue-engineered neointestine.
Journal of Pediatric Surgery, 2000
Journal of Pediatric Surgery, 2000
Journal of Pediatric Surgery, 2002
Conjoined twins are some of the most challenging patients faced by surgeons. Pygopagus and ischio... more Conjoined twins are some of the most challenging patients faced by surgeons. Pygopagus and ischiopagus twins present particular gastrointestinal and genitourinary reconstructive challenges. This study reviews the authors&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; experience with the perineal reconstruction of these types of conjoined twins. Retrospective analysis was performed for 3 sets of female conjoined twins undergoing separation between 1999 and 2001. Particular attention was given to the separation and reconstruction of the distal gastrointestinal and urogenital structures. Three sets of female conjoined twins underwent successful separation 2 pygopagus, one ischiopagus tripus) with 5 surviving infants. The sixth infant died of congenital anomalies incompatible with life. Four of the 5 surviving infants had diverting enterostomies. Two of these enterostomies have been closed. Perineal reconstruction consisted of anoplasty (5 of 5), vaginoplasty (4 of 5), and urethroplasty (4 of 5). Although fecal and urinary continence are not completely measurable at this age (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;3 years), all 5 survivors void spontaneously. Three infants with intestinal continuity have apparently normal defecation without the need of a bowel regimen. With careful preoperative planning and a multidisciplinary team of pediatric surgeons and urologists, satisfactory reconstruction and functional outcome of the female perineum can be achieved in conjoined twins.
Journal of Pediatric Surgery, 1998
Journal of Pediatric Surgery, 1999
Journal of Pediatric Surgery, 2005
The spleen arises from a mesenchymal bulge at the 6-mm stage of development. There are a wide var... more The spleen arises from a mesenchymal bulge at the 6-mm stage of development. There are a wide variety of splenic anomalies and variations that range from benign to clinically significant, and this article presents a brief review of splenic embryology and a case report of an anomalous splenic vein that precluded the formation of a Nissen fundoplication.
Journal of Pediatric Surgery, 2005
Fraternal twins with identical left-sided foramen of Morgagni hernias are described. The occurren... more Fraternal twins with identical left-sided foramen of Morgagni hernias are described. The occurrence of this rare type of congenital diaphragmatic hernia in twins suggests that genetic factors play a role in the formation of this lesion.
Journal of Pediatric Surgery, 2006
Traditional treatment of giant omphaloceles with silo closure has been associated with respirator... more Traditional treatment of giant omphaloceles with silo closure has been associated with respiratory insufficiency, hemodynamic compromise, dehiscence, and inability to close the abdomen with subsequent death. To minimize such complications, initial nonoperative management with delayed closure of the defect has been used. Methods: Between January 1981 and December 2002, 111 patients with omphaloceles were treated. Twenty-two patients with giant omphaloceles (19 containing liver) underwent initial nonoperative management consisting of silver sulfadiazine dressing changes. After pulmonary and other comorbidities stabilized, the contents were gradually reduced with a loose elastic bandage, and delayed closure was planned at 6 to 12 months. The medical records of these 22 patients were retrospectively reviewed to determine the efficacy and safety of this technique in the setting of severe associated anomalies. Those 15 patients (n = 15) from the latter 10 years were further reviewed to determine additional end points (length of hospital stay, length of intensive care unit stay, duration of mechanical ventilation, time to feed, time to closure, and type of closure). Results: Of the 15 patients treated during the latter 10 years, mean gestational age and birth weight were 38 F 1.4 weeks and 3.1 F 0.57 kg, respectively. Median length of stay after birth was 20 days (range, 5-239 days). Median time to full diet was 8 days (range, 4-80 days). Four patients were discharged on oral feedings only, 7 with combination oral/gavage, and 4 with tube feedings. Pulmonary hypoplasia or pulmonary hypertension was present in 11 (50%) of 22 patients. There were 11 patients with major cardiac anomalies, 14 with a patent ductus arteriosus, and 8 with a patent foramen ovale. Three early complications (2 ruptured sacs and 1 bleeding sac) and 1 late complication (gastric necrosis) occurred in the initial nonoperative period. In addition, 4 patients were treated for line sepsis, 1 patient for acute renal insufficiency, and 1 for aspiration pneumonia. Three patients required tracheostomy and were discharged with home ventilators. There were no complications associated with the use of silver sulfadiazine. Of the 22 patients, 16 have undergone delayed repair, 2 did not require repair, 1 is awaiting repair, 2 died before closure, and 1 was lost to follow-up. Delayed closure was achieved at a median age of 14 months (range, 2-28 months) and mean weight of 8.8 F 3.3 kg. Four patients required implantation of mesh for definitive closure. Median postoperative length of stay was 4 days (range,
Journal of Pediatric Surgery, 2009
The aim of the study was to investigate the effect of prophylactic cycling of parenteral nutritio... more The aim of the study was to investigate the effect of prophylactic cycling of parenteral nutrition (PN) on PN-induced cholestasis in patients with gastroschisis. Retrospective review of initial hospital admission charts for each patient with gastroschisis from 1996 to 2007 was performed. One hundred seven patients were analyzed (36 prophylactically cycled, 71 control). Prophylactic cycling of PN was initiated at a mean age of 23 days (range, 7-89 days). Patients were followed for a total of 4255 days with 27 developing hyperbilirubinemia (cycled, 5; continuous, 22). Time to hyperbilirubinemia was longer in the prophylactically cycled group (P = .005). Cumulative incidence of hyperbilirubinemia at 25 and 50 days of PN exposure was 5.7% and 9.8% (cycled) vs 22.3% and 48.8% (continuous). At any given time, children in the continuous group were 4.76 times more likely to develop hyperbilirubinemia (95% confidence interval, 1.62-14.00). After adjusting for confounding factors, children in the continuous group were 2.86 times more likely to develop hyperbilirubinemia (95% confidence interval, 0.86-9.53), but the difference was not significant (P = .088). Prophylactic cyclic PN is associated with a decreased incidence and prolonged time to onset of hyperbilirubinemia. Other factors, however, significantly affect this relationship. Prospective randomized investigation is warranted to investigate for a possible causal relationship.
Journal of Pediatric Gastroenterology and Nutrition, 2012
T o the Editor: We provided care to a 10-year-old girl who had placed 2 Buckyballs magnets in her... more T o the Editor: We provided care to a 10-year-old girl who had placed 2 Buckyballs magnets in her mouth as a makeshift tongue ring, and accidentally swallowed both magnets. An emergent esophagogastroduodenoscopy revealed that the magnets had passed beyond the duodenum. After 48 hours of conservative management, the magnets appeared to remain in a static position in the right lower quadrant. A limited noncontrast computed tomography scan of the abdomen showed both magnets attached to each other in the appendix. A diagnostic laparotomy was performed and under direct visualization, the magnets were manipulated into the appendix and retrieved via an appendectomy (Fig. 1). Her postoperative course was uneventful. After discharge from the hospital, this case received wide media coverage and was published on the front page of The Washington Post (1). During the same time, 2 other preteens were hospitalized at Inova Fairfax Hospital for Children with similar complaints. Both of them passed the objects spontaneously. Between 10% and 20% of cases require endoscopic retrieval, and approximately 1% of cases require operative management for intestinal obstruction or perforation (2,3) Reports from the Centers for Disease Control and Prevention and the US Consumer Product Safety Commission have described the risks of multiple magnet ingestion and have highlighted the dangers of using magnets as simulated jewelry, particularly around the lips and tongue (4,5). We urge the North American Society of Pediatric Gastroenterology, Hepatology, and Nutrition to assume a leadership role and take the initiative in educating and creating awareness among pediatricians, pediatric gastroenterologists, and other subspecialists about this emerging pediatric health concern.
Journal of Laparoendoscopic & Advanced Surgical Techniques, 2006
Although the laparoscopic approach to the treatment of complex biliary disease is possible, it is... more Although the laparoscopic approach to the treatment of complex biliary disease is possible, it is technically challenging. In an attempt to overcome these difficulties, the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, California) was used to facilitate the minimally invasive treatment of a type I choledochal cyst in a 5-year-old, 22 kg, girl. Complete resection of the choledochal cyst and a Roux-en-Y hepaticojejunostomy were performed using the robotic surgical system. Total robotic setup time (preparation, port placement, docking) was 40 minutes. Total procedure time was 440 minutes. Total robotic operative time was 390 minutes. No intraoperative complications or technical problems were encountered. At 6-month follow-up, the child is doing well with no episodes of cholangitis. Robot-assisted laparoscopic type I choledochal cyst resection appears safe and feasible. The three-dimensional visualization and wristed instrumentation greatly aids in the dissection of the cyst and in the biliary reconstruction.
Journal of Laparoendoscopic & Advanced Surgical Techniques, 2005
Laparoscopic pyloromyotomy (LPM) for the treatment of infantile hypertrophic pyloric stenosis (HP... more Laparoscopic pyloromyotomy (LPM) for the treatment of infantile hypertrophic pyloric stenosis (HPS) has gained popularity in recent years. This study examines the learning curve associated with LPM. We performed a retrospective analysis of patients undergoing LPM at a children&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s hospital between January 1, 1997 and June 30, 2003. Data including age, weight, complications, operative time, time to feeding, and length of postoperative stay were analyzed using the Student&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s ttest. A total of 51 patients underwent LPM during the study period. Patient characteristics were similar throughout the study period. Operative time ranged from 12 to 55 minutes (mean, 25 minutes). Mean operative time decreased significantly from 31+/-11 minutes for the first 15 patients, to 25+/-6 minutes for the second 15 patients, to 20+/-7 minutes for the last 15 patients (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). Operative times were erratic for the early cases but became more consistent over time, especially after 30 cases. Conversion to an open procedure was required in two patients. Complications included an umbilical port site wound dehiscence and readmission for persistent vomiting. There were no mucosal perforations. Time to ad lib feeding and postoperative length of stay did not change over time. LPM has a steep learning curve, especially for the first 15 patients. Operative time decreases and becomes more consistent after about 30 cases. Despite the learning curve, LPM can be performed safely and effectively without an increase in complications.
The Journal of Trauma: Injury, Infection, and Critical Care, 2000
... Case Reports. Hemosuccus Pancreaticus after Penetrating Trauma to the Abdomen. Kim, Stephen S... more ... Case Reports. Hemosuccus Pancreaticus after Penetrating Trauma to the Abdomen. Kim, Stephen S. MD; Roberts, Roxanne R. MD; Nagy, Kimberly K. MD; Joseph, Kimberly MD; Bokhari, Faran MD; An, Gary MD; Barrett, John MD. ... 2000 Lippincott Williams &amp; Wilkins, Inc. ...
Transplantation, 1998
Our laboratory is investigating the tissue engineering of small intestine using intestinal epithe... more Our laboratory is investigating the tissue engineering of small intestine using intestinal epithelial organoid units seeded onto highly porous biodegradable polymer tubes. This study investigated methods of stimulation for optimizing neointestinal regeneration. Intestinal epithelial organoid units harvested from neonatal Lewis rats were seeded onto porous biodegradable polymer tubes and implanted into the omentum of adult Lewis rats in the following groups: (1) the control group (group C), implantation alone (n=9); (2) the small bowel resection (SBr) group, after 75% SBr (n=9); (3) the portacaval shunt (PCS) group, after PCS (n=8); and (4) the partial hepatectomy (PH) group, after 75% PH (n=8). Neointestinal cyst size was recorded using ultrasonography. Constructs were harvested at 10 weeks and were examined using histology. Morphometric analysis of the neomucosa was obtained using a computer image analysis program (NIH Image, version 1.59). Cyst development was noted in all animals. Cyst lengths and diameters were significantly larger in the SBr group at 7 and 10 weeks compared with the other three groups (P<0.05; analysis of variance [ANOVA], Fisher's protected least significant difference). Histology revealed a well-vascularized tissue with a neomucosa lining the lumen with invaginations resembling crypt-villus structures. Morphometric analysis demonstrated a significantly greater villus number, height, area, and mucosal surface in the SBr group compared with the other three groups and a significantly greater crypt number and area in the PCS group compared with group C (P<0.05; ANOVA, Fisher's protected least significant difference). Intestinal epithelial organoid units transplanted on porous biodegradable polymer tubes can successfully vascularize, survive, and regenerate into complex tissue resembling small intestine. SBr and, to a lesser extent, PCS provide significant regenerative stimuli for the morphogenesis and differentiation of tissue-engineered small intestine.
Transplantation, 1999
Our laboratory has investigated the fabrication of a tissue-engineered intestine using biodegrada... more Our laboratory has investigated the fabrication of a tissue-engineered intestine using biodegradable polymer scaffolds. Previously we reported that isolated intestinal epithelial organoid units on biodegradable polymer scaffolds formed cysts and the neointestine was successfully anastomosed to the native small bowel. The purpose of this study was to observe the development of tissue-engineered intestine after anastomosis and to demonstrate the effect of the anastomosis over a 9-month period. Microporous biodegradable polymer tubes were created from polyglycolic acid. Intestinal epithelial organoid units were harvested from neonatal Lewis rats and seeded onto the polymers, which were implanted into the abdominal cavity of adult male Lewis rats followed by 75% small bowel resection (n=24). Three weeks after implantation, the unit/polymer constructs were anastomosed to the native jejunum in a side-to-side fashion. The anastomosed tissue-engineered intestine was measured by laparotomy 10, 24, and 36 weeks after the implantation (n= 14). During the laparotomy, all rats with an obstruction in their anastomosis were killed and excluded from the statistical analysis. Another five rats were also killed at 10 and 36 weeks for histological and morphometric studies. All analyzed rats survived this study and significantly increased their body weight by 36 weeks. Obstruction of the anastomosis was observed in one rat at 24 weeks and in two rats at 36 weeks; however, the anastomosis was patent in the other 11 rats by 36 weeks. The tissue-engineered intestine of these 11 rats increased in length and diameter at 10, 24, and 36 weeks after anastomosis; there were statistically significant differences between each time point except between the length of 10 and 24 weeks (P<0.016 by Wilcoxon signed rank test). Histologically the inner surface of the tissue-engineered intestine was lined with well-developed neomucosa at 10 and 36 weeks; however, there were small bare areas lacking neomucosa in the tissue-engineered intestine at 36 weeks. Morphometric analysis demonstrated no significant differences in villus number, villus height, and surface length of the neomucosa at 10 and 36 weeks. Anastomosis between tissue-engineered intestine and native small bowel resulted in no complications after operation and maintained a high patency rate for up to 36 weeks. The tissue-engineered intestine increased in size and was lined with well-developed neomucosa for the duration of the study.
Tissue Engineering, 1999
Background. Previous work from this laboratory has shown that isolated intestinal epithelial orga... more Background. Previous work from this laboratory has shown that isolated intestinal epithelial organoid units on porous biodegradable polymer scaffolds formed vascularized cysts lined by a neomucosa. The purpose of this study was to demonstrate anastomosis between tissue-engineered intestine and the native small bowel and to observe the effect of this anastomosis on cyst growth. Methods. Intestinal epithelial organoid units from neonatal Lewis rats were seeded onto porous biodegradable polymer tubes made of polyglycolic acid, and they were implanted into the omentum of adult male Lewis rats. Three weeks after implantation, the unitpolymer constructs were anastomosed in a side-to-side fashion to the native jejunum in 20 rats (group 1). The other 18 rats were closed without anastomosis (group 2). All 38 tissue-engineered constructs were harvested 10 weeks after implantation. Four rats underwent upper gastrointestinal (GI) study before they were killed. Results. The rats in group 1 increased their body weights equal to those in group 2, and there was no statistically significant difference between the two groups. Upper GI examinations revealed no evidence of either bowel stenosis or obstruction at the anastomotic site. Grossly, the patency of the anastomosis was 90% and the lumen of the cyst was visualized by the upper GI study. At the second operation, there was no significant difference in the size of the cysts in either group: however, at the time the rats were killed, the length of the cysts in group 1 was significantly longer than that in group 2 (P<0.05 using Mann-Whitney U test). Histological examination showed that cysts after anastomosis were lined by a neomucosa in continuity to native small bowel across the anastomotic site and also demonstrated crypt-villus structures. Morphometric study demonstrated that cysts in group 1 had significantly greater villus number, height, and surface length than did those in group 2. Conclusions. Anastomosis between tissue-engineered intestine and native small bowel resulted in no complications after the operation, kept a high patency rate, and maintained mucosal continuity between the tissue-engineered intestine and native small bowel. Furthermore, anastomosis had a positive effect on cyst size and development of the mucosa in the tissue-engineered intestine.
The American Journal of Surgery, 2008
The purpose of this study was to present 3 cases of left-sided gastroschisis and review the liter... more The purpose of this study was to present 3 cases of left-sided gastroschisis and review the literature concerning this rare condition. METHODS: Charts of 3 previously unreported patients with left-sided gastroschisis were reviewed. A literature review of all cases of left-sided gastroschisis was completed. RESULTS: Sixteen patients with left-sided defects were identified, only 12 of whom had classic periumbilical defects. We present 3 additional patients. Eleven of 15 patients were female, with 1 patient's sex not reported. Forty percent had extraintestinal anomalies. CONCLUSIONS: Left-sided gastroschisis is more common in females and associated with a higher incidence of extraintestinal anomalies compared with right-sided lesions. Although the etiology remains unknown, it may differ from that of right-sided gastroschisis.
The Journal of Trauma: Injury, Infection, and Critical Care, 2009
The Heimlich maneuver is a well-described emergency procedure for management of foreign body airw... more The Heimlich maneuver is a well-described emergency procedure for management of foreign body airway obstructions. Although rare, complications of the Heimlich maneuver do exist. The purpose of this report is to review the known complications of this procedure. All reported complications published in English on Medline and PubMed were reviewed. Additionally, we present a rare case of acute pancreatitis with associated pseudocyst formation after the administration of the Heimlich maneuver on a healthy 3-year-old boy. Although life saving, the Heimlich maneuver may be associated with significant complications; thus, symptomatic patients after this maneuver should be thoroughly evaluated with appropriate laboratory and radiographic studies.
Journal of Surgical Research, 1999
Our laboratory is investigating the tissue engineering of small intestine using intestinal epithe... more Our laboratory is investigating the tissue engineering of small intestine using intestinal epithelial organoid units seeded onto highly porous biodegradable polymer matrices. This study investigated the effects of anastomosis of tissue-engineered intestine to native small bowel alone or combined with small bowel resection on neointestinal regeneration. Intestinal epithelial organoid units harvested from neonatal Lewis rats were seeded onto biodegradable polymer tubes and implanted into the omentum of adult Lewis rats as follows: (1) implantation alone (n = 9); (2) implantation followed by anastomosis to native small bowel at 3 weeks (n = 11); and (3) implantation after small bowel resection and anastomosis to native small bowel at 3 weeks (n = 8). All constructs were harvested at 10 weeks and examined by histology. Morphometric analysis of the neomucosa was obtained using a computer image analysis program. Cyst development was noted in all animals. All anastomoses were patent at 10 weeks. Histology revealed the development of a vascularized tissue with a neomucosa lining the lumen of the cyst with invaginations resembling crypt-villus structures. Morphometric analysis demonstrated significantly greater villus number, villus height, crypt number, crypt area, and mucosal surface length in groups 2 and 3 compared with group 1, and significantly greater villus number, villus height, crypt area, and mucosal surface length in group 3 compared with group 2 (P < 0.05, ANOVA, Tukey test). Intestinal epithelial organoid units transplanted on biodegradable polymer tubes can regenerate into complex tissue resembling small intestine. Anastomosis to native small bowel combined with small bowel resection and anastomosis alone contribute significant regenerative stimuli for the morphogenesis and differentiation of tissue-engineered neointestine.
Journal of Pediatric Surgery, 2000
Journal of Pediatric Surgery, 2000
Journal of Pediatric Surgery, 2002
Conjoined twins are some of the most challenging patients faced by surgeons. Pygopagus and ischio... more Conjoined twins are some of the most challenging patients faced by surgeons. Pygopagus and ischiopagus twins present particular gastrointestinal and genitourinary reconstructive challenges. This study reviews the authors&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; experience with the perineal reconstruction of these types of conjoined twins. Retrospective analysis was performed for 3 sets of female conjoined twins undergoing separation between 1999 and 2001. Particular attention was given to the separation and reconstruction of the distal gastrointestinal and urogenital structures. Three sets of female conjoined twins underwent successful separation 2 pygopagus, one ischiopagus tripus) with 5 surviving infants. The sixth infant died of congenital anomalies incompatible with life. Four of the 5 surviving infants had diverting enterostomies. Two of these enterostomies have been closed. Perineal reconstruction consisted of anoplasty (5 of 5), vaginoplasty (4 of 5), and urethroplasty (4 of 5). Although fecal and urinary continence are not completely measurable at this age (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;3 years), all 5 survivors void spontaneously. Three infants with intestinal continuity have apparently normal defecation without the need of a bowel regimen. With careful preoperative planning and a multidisciplinary team of pediatric surgeons and urologists, satisfactory reconstruction and functional outcome of the female perineum can be achieved in conjoined twins.
Journal of Pediatric Surgery, 1998
Journal of Pediatric Surgery, 1999
Journal of Pediatric Surgery, 2005
The spleen arises from a mesenchymal bulge at the 6-mm stage of development. There are a wide var... more The spleen arises from a mesenchymal bulge at the 6-mm stage of development. There are a wide variety of splenic anomalies and variations that range from benign to clinically significant, and this article presents a brief review of splenic embryology and a case report of an anomalous splenic vein that precluded the formation of a Nissen fundoplication.
Journal of Pediatric Surgery, 2005
Fraternal twins with identical left-sided foramen of Morgagni hernias are described. The occurren... more Fraternal twins with identical left-sided foramen of Morgagni hernias are described. The occurrence of this rare type of congenital diaphragmatic hernia in twins suggests that genetic factors play a role in the formation of this lesion.
Journal of Pediatric Surgery, 2006
Traditional treatment of giant omphaloceles with silo closure has been associated with respirator... more Traditional treatment of giant omphaloceles with silo closure has been associated with respiratory insufficiency, hemodynamic compromise, dehiscence, and inability to close the abdomen with subsequent death. To minimize such complications, initial nonoperative management with delayed closure of the defect has been used. Methods: Between January 1981 and December 2002, 111 patients with omphaloceles were treated. Twenty-two patients with giant omphaloceles (19 containing liver) underwent initial nonoperative management consisting of silver sulfadiazine dressing changes. After pulmonary and other comorbidities stabilized, the contents were gradually reduced with a loose elastic bandage, and delayed closure was planned at 6 to 12 months. The medical records of these 22 patients were retrospectively reviewed to determine the efficacy and safety of this technique in the setting of severe associated anomalies. Those 15 patients (n = 15) from the latter 10 years were further reviewed to determine additional end points (length of hospital stay, length of intensive care unit stay, duration of mechanical ventilation, time to feed, time to closure, and type of closure). Results: Of the 15 patients treated during the latter 10 years, mean gestational age and birth weight were 38 F 1.4 weeks and 3.1 F 0.57 kg, respectively. Median length of stay after birth was 20 days (range, 5-239 days). Median time to full diet was 8 days (range, 4-80 days). Four patients were discharged on oral feedings only, 7 with combination oral/gavage, and 4 with tube feedings. Pulmonary hypoplasia or pulmonary hypertension was present in 11 (50%) of 22 patients. There were 11 patients with major cardiac anomalies, 14 with a patent ductus arteriosus, and 8 with a patent foramen ovale. Three early complications (2 ruptured sacs and 1 bleeding sac) and 1 late complication (gastric necrosis) occurred in the initial nonoperative period. In addition, 4 patients were treated for line sepsis, 1 patient for acute renal insufficiency, and 1 for aspiration pneumonia. Three patients required tracheostomy and were discharged with home ventilators. There were no complications associated with the use of silver sulfadiazine. Of the 22 patients, 16 have undergone delayed repair, 2 did not require repair, 1 is awaiting repair, 2 died before closure, and 1 was lost to follow-up. Delayed closure was achieved at a median age of 14 months (range, 2-28 months) and mean weight of 8.8 F 3.3 kg. Four patients required implantation of mesh for definitive closure. Median postoperative length of stay was 4 days (range,
Journal of Pediatric Surgery, 2009
The aim of the study was to investigate the effect of prophylactic cycling of parenteral nutritio... more The aim of the study was to investigate the effect of prophylactic cycling of parenteral nutrition (PN) on PN-induced cholestasis in patients with gastroschisis. Retrospective review of initial hospital admission charts for each patient with gastroschisis from 1996 to 2007 was performed. One hundred seven patients were analyzed (36 prophylactically cycled, 71 control). Prophylactic cycling of PN was initiated at a mean age of 23 days (range, 7-89 days). Patients were followed for a total of 4255 days with 27 developing hyperbilirubinemia (cycled, 5; continuous, 22). Time to hyperbilirubinemia was longer in the prophylactically cycled group (P = .005). Cumulative incidence of hyperbilirubinemia at 25 and 50 days of PN exposure was 5.7% and 9.8% (cycled) vs 22.3% and 48.8% (continuous). At any given time, children in the continuous group were 4.76 times more likely to develop hyperbilirubinemia (95% confidence interval, 1.62-14.00). After adjusting for confounding factors, children in the continuous group were 2.86 times more likely to develop hyperbilirubinemia (95% confidence interval, 0.86-9.53), but the difference was not significant (P = .088). Prophylactic cyclic PN is associated with a decreased incidence and prolonged time to onset of hyperbilirubinemia. Other factors, however, significantly affect this relationship. Prospective randomized investigation is warranted to investigate for a possible causal relationship.
Journal of Pediatric Gastroenterology and Nutrition, 2012
T o the Editor: We provided care to a 10-year-old girl who had placed 2 Buckyballs magnets in her... more T o the Editor: We provided care to a 10-year-old girl who had placed 2 Buckyballs magnets in her mouth as a makeshift tongue ring, and accidentally swallowed both magnets. An emergent esophagogastroduodenoscopy revealed that the magnets had passed beyond the duodenum. After 48 hours of conservative management, the magnets appeared to remain in a static position in the right lower quadrant. A limited noncontrast computed tomography scan of the abdomen showed both magnets attached to each other in the appendix. A diagnostic laparotomy was performed and under direct visualization, the magnets were manipulated into the appendix and retrieved via an appendectomy (Fig. 1). Her postoperative course was uneventful. After discharge from the hospital, this case received wide media coverage and was published on the front page of The Washington Post (1). During the same time, 2 other preteens were hospitalized at Inova Fairfax Hospital for Children with similar complaints. Both of them passed the objects spontaneously. Between 10% and 20% of cases require endoscopic retrieval, and approximately 1% of cases require operative management for intestinal obstruction or perforation (2,3) Reports from the Centers for Disease Control and Prevention and the US Consumer Product Safety Commission have described the risks of multiple magnet ingestion and have highlighted the dangers of using magnets as simulated jewelry, particularly around the lips and tongue (4,5). We urge the North American Society of Pediatric Gastroenterology, Hepatology, and Nutrition to assume a leadership role and take the initiative in educating and creating awareness among pediatricians, pediatric gastroenterologists, and other subspecialists about this emerging pediatric health concern.
Journal of Laparoendoscopic & Advanced Surgical Techniques, 2006
Although the laparoscopic approach to the treatment of complex biliary disease is possible, it is... more Although the laparoscopic approach to the treatment of complex biliary disease is possible, it is technically challenging. In an attempt to overcome these difficulties, the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, California) was used to facilitate the minimally invasive treatment of a type I choledochal cyst in a 5-year-old, 22 kg, girl. Complete resection of the choledochal cyst and a Roux-en-Y hepaticojejunostomy were performed using the robotic surgical system. Total robotic setup time (preparation, port placement, docking) was 40 minutes. Total procedure time was 440 minutes. Total robotic operative time was 390 minutes. No intraoperative complications or technical problems were encountered. At 6-month follow-up, the child is doing well with no episodes of cholangitis. Robot-assisted laparoscopic type I choledochal cyst resection appears safe and feasible. The three-dimensional visualization and wristed instrumentation greatly aids in the dissection of the cyst and in the biliary reconstruction.
Journal of Laparoendoscopic & Advanced Surgical Techniques, 2005
Laparoscopic pyloromyotomy (LPM) for the treatment of infantile hypertrophic pyloric stenosis (HP... more Laparoscopic pyloromyotomy (LPM) for the treatment of infantile hypertrophic pyloric stenosis (HPS) has gained popularity in recent years. This study examines the learning curve associated with LPM. We performed a retrospective analysis of patients undergoing LPM at a children&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s hospital between January 1, 1997 and June 30, 2003. Data including age, weight, complications, operative time, time to feeding, and length of postoperative stay were analyzed using the Student&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s ttest. A total of 51 patients underwent LPM during the study period. Patient characteristics were similar throughout the study period. Operative time ranged from 12 to 55 minutes (mean, 25 minutes). Mean operative time decreased significantly from 31+/-11 minutes for the first 15 patients, to 25+/-6 minutes for the second 15 patients, to 20+/-7 minutes for the last 15 patients (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). Operative times were erratic for the early cases but became more consistent over time, especially after 30 cases. Conversion to an open procedure was required in two patients. Complications included an umbilical port site wound dehiscence and readmission for persistent vomiting. There were no mucosal perforations. Time to ad lib feeding and postoperative length of stay did not change over time. LPM has a steep learning curve, especially for the first 15 patients. Operative time decreases and becomes more consistent after about 30 cases. Despite the learning curve, LPM can be performed safely and effectively without an increase in complications.