Human hepatocytes and hematolymphoid dual reconstitution in treosulfan-conditioned uPA-NOG mice.

Human-specific HIV-1 and hepatitis co-infections significantly affect patient management and call for new therapeutic options. Small xenotransplantation models with human hepatocytes and hematolymphoid tissue should facilitate antiviral/antiretroviral drug trials. However, experience with mouse strains tested for dual reconstitution is limited, with technical difficulties such as risky manipulations with newborns and high mortality rates due to metabolic abnormalities. The best animal strains for hepatocyte transplantation are not optimal for human hematopoietic stem cell (HSC) engraftment, and vice versa. We evaluated a new strain of highly immunodeficient nonobese diabetic/Shi-scid (severe combined immunodeficiency)/IL-2Rγc(null) (NOG) mice that carry two copies of the mouse albumin promoter-driven urokinase-type plasminogen activator transgene for dual reconstitution with human liver and immune cells. Three approaches for dual reconstitution were evaluated: i) freshly isolated fetal hepatoblasts were injected intrasplenically, followed by transplantation of cryopreserved HSCs obtained from the same tissue samples 1 month later after treosulfan conditioning; ii) treosulfan conditioning is followed by intrasplenic simultaneous transplantation of fetal hepatoblasts and HSCs; and iii) transplantation of mature hepatocytes is followed by mismatched HSCs. The long-term dual reconstitution was achieved on urokinase-type plasminogen activator-NOG mice with mature hepatocytes (not fetal hepatoblasts) and HSCs. Even major histocompatibility complex mismatched transplantation was sustained without any evidence of hepatocyte rejection by the human immune system.

Laparoscopic cholecystectomy for biliary dyskinesia in children: frequency increasing.

PURPOSE: The treatment of children with biliary dyskinesia (BD) is controversial. As we recently observed an increasing frequency of referrals for BD in our institution the aim of the study was to re-evaluate the long-term outcome in children with BD. METHODS: Children with laparoscopic cholecystectomy (LC) for suspected BD between 8/2006 and 5/2011 were included. A pathologic ejection fraction (EF) was defined as <35%. The long-term effect of cholecystectomy was assessed via a Likert scale symptom questionnaire. RESULTS: 82 children (median age 13.5 years, mean BMI 25.8) were included. CCK-HIDA scan was pathologic in 74 children (90.2%). Mean EF was 16.4%. Histology revealed chronic cholecystitis in 48 (58.5%) children and was normal in 30 children (36.5%). The frequency of LC for suspected BD increased by a factor of 4.3 in the last 10 years. Long term follow-up showed that only 23/52 children (44.2%) were symptom-free after LC. Patients with chronic inflammation were more likely to have persistent symptoms (p=0.017). An EF<15% was associated with a resolution of symptoms (p=0.031). CONCLUSION: The frequency of LC for suspected BD in our institution has increased significantly during recent years. The long-term efficacy in our cohort was only 44.2%. We believe that laparoscopic cholecystectomy is likely helpful in patients with an EF<15%. However, in children with an EF of 15%-35%, based upon our data, we would highly recommend an appropriately thorough pre-op testing to exclude other gastrointestinal disorders prior to consideration of operative management.

Single incision pediatric endosurgery (SIPES) appendectomy--is obesity a contraindication?

INTRODUCTION: Single-incision pediatric endosurgery (SIPES) is gaining popularity and has been reported to be safe in acute (non-perforated) and perforated appendicitis. The feasibility of SIPES appendectomy in obese children is uncertain. MATERIALS AND METHODS: After IRB approval, data were collected from a prospectively maintained SIPES appendectomy database for cases performed between April 2009 and March 2012. Patients were divided into obese and non-obese groups based on Center for Disease Control criteria. The surgical techniques, operative times, complications, conversion rates, and outcomes were recorded. Chi-square test and t-test were used for statistical analysis. RESULTS: SIPES appendectomy was attempted in 500 children. There were 21% obese, and 37% were female with median age of 10.9 ± 3.8 years. Mean operative time, blood loss, requirement of additional trocars, and intraoperative complications in non-obese and obese children were not significantly different. Mean hospital stay (2.3 days in each group), post operative wound infections (3.3% vs. 4.8%, p=0.55, non-obese vs. obese), and intraabdominal abscesses (4.3% vs. 2.9%, p=0.77, non-obese vs. obese) were not significantly different. CONCLUSION: SIPES appendectomy may be accomplished successfully and safely in obese children. Obesity did not appear to be associated with increased risk of complications and was not a contraindication for SIPES appendectomy.

Single-incision pediatric endosurgery for ovarian pathology.

BACKGROUND AND OBJECTIVES: Despite being pioneered by gynecologists, single-incision endosurgery has not been widely reported for the treatment of ovarian and adnexal pathology in neonates, children, and adolescents. We describe our initial experience using single-incision pediatric endosurgery (SIPES) for these indications and discuss advantages and drawbacks. SUBJECTS AND METHODS: All children who underwent SIPES with a preoperative diagnosis of ovarian or adnexal pathology were included in the study. Data on age, operative time, complications, length of hospital stay, and outcomes were collected. RESULTS: From January 2010 until January 2012, 19 girls (mean age, 11.4 years; range, 6 days-17 years; weight range, 4.0-90 kg) underwent SIPES procedures for ovarian or adnexal diagnoses, including hemorrhagic/follicular/paratubal cysts (n=8), torsion (n=7), tumor (n=3), and parauterine cyst (n=1). The operations included cyst unroofing (n=4), detorsion and oophoropexy (n=7), (salpingo)oophorectomy (n=5), marsupialization of cyst (n=2), and cyst aspiration (n=1). Median operative time was 42 ± 29 minutes; there were no conversions to conventional laparoscopy or open surgery. Fifteen patients (79%) were discharged within 24 hours after the procedure. There were no peri- or postoperative complications. Histopathology showed hemorrhagic/follicular/paratubal cyst (n=7), necrotic/calcified ovarian tissue after torsion (n=6), cystadenofibroma (n=1), granulosa cell tumor (n=1), and mature teratoma (Grade 0) (n=1). CONCLUSIONS: SIPES is an excellent alternative to conventional laparoscopy for the treatment of adnexal pathology. Using a single umbilical incision that can be enlarged instead of three smaller trocar sites facilitates the resection and extraction of ovarian masses without compromising cosmesis.

Single-incision pediatric endosurgery (SIPES) splenectomy: a case-control series.

BACKGROUND/PURPOSE: Single-incision pediatric endosurgery (SIPES) is gaining popularity. The aim of this study was to review the authors' experience with SIPES splenectomy and compare it with conventional laparoscopic splenectomy. SUBJECTS AND METHODS: After institutional review board approval, data on SIPES splenectomy in children were collected prospectively. The study group was compared with a control group of patients who were retrospectively identified as having undergone conventional laparoscopic splenectomy during the same time period. RESULTS: Sixteen children underwent SIPES splenectomy. Ages ranged from 1 to 15 years, with a median of 7 years, and weights were between 10 and 70 kg, with a median of 24 kg. The control group was similar in age and weight characteristics. The most common diagnoses were hereditary spherocytosis, sickle cell disease, and immune thrombocytopenic purpura. There were two conversions to open splenectomy in the SIPES group and one in the laparoscopic group. Operative times were 40-190 minutes (median, 84 minutes) in the SIPES group and 51-154 minutes (median, 99 minutes) in the conventional laparoscopic group. CONCLUSIONS: The SIPES technique is well suited for splenectomy. Despite instruments and camera being in-line, working angles are not compromised, and visualization is adequate. Operating time and hospital stay are comparable to those with standard laparoscopic splenectomy, but the cosmetic result may be superior.

Angiodysplasia (vascular malformations) of the colon presenting as an acute abdomen.

Angiodysplasia (vascular malformations) of the colon is extremely rare in children, and, as in adults, present with lower gastrointestinal hemorrhage. Here we report an unusual pediatric case of angiodysplasia of the terminal ileum and cecum presenting as an acute abdomen with radiological features suggestive of lymphoma.

Feasibility of single-incision pediatric endosurgery for treatment of appendicitis in 415 children.

INTRODUCTION: Single-incision pediatric endosurgery (SIPES) has gained popularity for ablative procedures such as appendectomy in many pediatric surgical centers. This study evaluates the outcome of SIPES for treatment of appendicitis in our institution. PATIENTS AND METHODS: After Institutional Review Board approval was obtained, data were prospectively collected on all patients undergoing SIPES appendectomy in our hospital from March 2009 through October 2011. The surgical techniques, operative times, complications, conversion rates, and outcomes were recorded. RESULTS: SIPES appendectomy was attempted in 415 children (mean age, 10.9 years; age range, 1.4-17.9 years; 266 males, 149 females; median weight, 43 kg; weight range, 9.8-146 kg). Intraoperatively, acute appendicitis was found in 298 cases and perforated appendicitis in 79 cases. Thirty-eight patients underwent interval appendectomy. Appendectomy was carried out solely as SIPES in 397 cases (96%). Median operative time was 40±16 minutes (37±16 minutes for fellows [n=284] and 46±15 minutes for residents [n=131]). There were three intraoperative complications, which could be handled during the procedure. Pathologic reports revealed inflammatory changes of the appendix (n=386), other pathology (n=11), and no pathologic change (n=18). Overall, 24 patients (5.8%) were readmitted for intra-abdominal abscess (n=14), umbilical wound infection (n=3), and other reasons (n=7). Twelve patients (2.9%) underwent reoperation: drainage of intra-abdominal abscess (n=8) (3 by the surgeon, 5 by the interventional radiologist), wound drainage (n=3), and right hemicolectomy for carcinoid (n=1). In perforated appendicitis the postoperative intra-abdominal abscess rate was 10 of 79 cases (12.7%), which is similar to the previous report with conventional laparoscopic appendectomy from our institution (13.6%). The wound infection rate (5 of 79 cases [6.3%]) was also similar to the previously report (6.8%) with conventional laparoscopic appendectomy for perforated appendicitis. CONCLUSIONS: Appendectomy can be accomplished successfully and safely using single-incision endosurgery in children with acceptable operative times without leaving any appreciable scar. Additional trocars are infrequently necessary. So far, the intraoperative and postoperative complication rates are comparable to those of triangulated laparoscopic appendectomy.

Spontaneous hepatic repopulation in transgenic mice expressing mutant human α1-antitrypsin by wild-type donor hepatocytes.

α1-Antitrypsin deficiency is an inherited condition that causes liver disease and emphysema. The normal function of this protein, which is synthesized by the liver, is to inhibit neutrophil elastase, a protease that degrades connective tissue of the lung. In the classical form of the disease, inefficient secretion of a mutant α1-antitrypsin protein (AAT-Z) results in its accumulation within hepatocytes and reduced protease inhibitor activity, resulting in liver injury and pulmonary emphysema. Because mutant protein accumulation increases hepatocyte cell stress, we investigated whether transplanted hepatocytes expressing wild-type AAT might have a competitive advantage relative to AAT-Z-expressing hepatocytes, using transgenic mice expressing human AAT-Z. Wild-type donor hepatocytes replaced 20%-98% of mutant host hepatocytes, and repopulation was accelerated by injection of an adenovector expressing hepatocyte growth factor. Spontaneous hepatic repopulation with engrafted hepatocytes occurred in the AAT-Z-expressing mice even in the absence of severe liver injury. Donor cells replaced both globule-containing and globule-devoid cells, indicating that both types of host hepatocytes display impaired proliferation relative to wild-type hepatocytes. These results suggest that wild-type hepatocyte transplantation may be therapeutic for AAT-Z liver disease and may provide an alternative to protein replacement for treating emphysema in AAT-ZZ individuals.