Successful treatment of young childhood standard-risk hepatoblastoma with cisplatin monotherapy using a central review system.

BACKGROUND: The JPLT3-S (Japanese Study Group for Pediatric Liver Tumors-3) study, conducted cisplatin (CDDP) monotherapy for young children (<3 years old) with standard-risk hepatoblastoma (HB) using a central review system in Japan. In the previous JPLT2 study, cases with resectable tumors without any annotation factors in the PRETEXT (PRETreatment EXTent of disease) classification (standard-risk HB) showed favorable outcomes with treatment consisting of CDDP and pirarubicin, but showed toxicities and late complications. In the JPLT3-S trial, a less intense regimen consisting of CDDP alone was evaluated. METHODS: Patients who were less than 3 years of age and with PRETEXT I, II, or III HB without any annotation factors (e.g., E1, E1a, E2, E2a, H1, N1, P2, P2a, V3, and V3a) were eligible for inclusion in this study. In this trial, the central radiological and pathological features of all patients were reviewed. The primary outcome was the 3-year progression-free survival (PFS). RESULTS: A total of 38 patients (23 female) were included. The median patient age was 12 months (range: 2-34). Two patients discontinued treatment because of progressive disease, and five patients discontinued treatment for other reasons. The 3-year PFS rate was 93.9% (95% confidence interval [CI]: 86.4%-100%). All 38 patients survived (follow-up period 38-98 months), and the OS rate was 100% (CI: 100). Eighteen of the 38 patients (47.4%) experienced ototoxicity as a late complication. CONCLUSION: CDDP monotherapy regimen is feasible in young patients with localized HB, as classified by a central review.

Selective enlargement of left lateral segment liver volume as a potential diagnostic predictor for biliary atresia.

PURPOSE: To determine an early diagnostic indicator of biliary atresia (BA), we focused on morphological left-right differences of BA livers. METHODS: Of 74 infants with suspected BA at our hospital in the last 12 years, 25 met the conditions for investigation: 15 infants with BA (BA group) and 10 with other pathologies (non-BA group). CT volumetry of the liver in each patient was performed using a 3D image analysis system. Patient characteristics, blood data, and proportion of the left lateral segment to the total liver volume (LLS ratio) were compared between the two groups. RESULTS: Among the patient characteristics and liver function tests, only γ-glutamyl transpeptidase (GGT) were significantly higher in the BA group (p < 0.001). The LLS ratio was 0.321 (0.227-0.382) in the BA group and 0.243 (0.193-0.289) in the non-BA group (p = 0.01). The summary cut-off, area under the curve, sensitivity, and specificity were 0.322, 0.813, 53.3, and 100% for the LLS ratio and 94.26, 0.95, 86.7, and 100% for the GGT × LLS ratio, respectively. CONCLUSIONS: The LLS ratio is highly specific and may be an early diagnostic predictor of BA. Moreover, this segmental LLS enlargement may be associated with the etiology of BA.

Feasibility of Real-Time Central Surgical Review for Patients with Advanced-Stage Hepatoblastoma in the JPLT3 Trial.

In the JPLT3 study, a real-time central surgical reviewing (CSR) system was employed aimed at facilitating early referral of candidates for liver transplantation (LTx) to centers with pediatric LTx services. The expected consequence was surgery, including LTx, conducted at the appropriate time in all cases. This study aimed to review the effect of CSR on institutional surgical decisions in cases enrolled in the JPLT3 study. Real-time CSR was performed in cases in which complex surgeries were expected, using images obtained after two courses of preoperative chemotherapy. Using the cloud-based remote image viewing system, an expert panel consisting of pediatric and transplant surgeons reviewed the images and commented on the expected surgical strategy or the necessity of transferring the patient to a transplant unit. The results were summarized and reported to the treating institutions. A total of 41 reviews were conducted for 35 patients, and 16 cases were evaluated as possible candidates for LTx, with the treating institutions being advised to consult a transplant center. Most of the reviewed cases promptly underwent definitive liver surgeries, including LTx per protocol.

A study of the mechanisms responsible for the action of new immunosuppressants and their effects on rat small intestinal transplantation.

In a series of studies, using an identical rat intestinal transplantation model, we evaluated the effects of several drugs. FK-506 caused a significant attenuation in the proliferation of allogeneic CD4+ T cells and IFN-γ secreting effector functions. FYT720 resulted in a marked reduction in the numbers of lymphocytes, associated with a reduction of T cell recruitment, in grafts. An anti-MAdCAM antibody was next reported to significantly down-regulate CD4+ T cell infiltration in intestinal grafts by blocking the adhesion molecule, and could be useful as an induction therapy. Concerning TAK-779, this CCR5 and CXCR3 antagonist diminished the number of graft-infiltrating cells by suppressing the expression of their receptors in the graft. As a result, it reduced the total number of recipient T cells involved in graft rejection. As the next step, we focused on the participation of monocytes/ macrophages in this field. PQA-18 has been the focus of a novel immunosuppressant that attenuates not only the production of various cytokines, such as IL-2 & TNF-α, on T cells, but the differentiation of macrophages by inhibiting PAK2 as well. In this report, we summarize our previous studies not only regarding the above drugs, but on an anti-complement drug and a JAK inhibitor as well.

Results of mass screening for neuroblastoma in 18-month-old infants in Osaka area, Japan.

PURPOSE: In 2004, the Japanese government halted nationwide mass screening for neuroblastoma in 6-month-old infants as it led to overdiagnosis of localized tumors with favorable prognoses and failed to reduce neuroblastoma-related mortality. However, a new mass screening program for neuroblastoma in 18-month-old infants (18MS) was conducted in the Osaka prefecture. We assessed the efficacy of the 18MS in screening unfavorable cases. METHODS: Public health centers in Osaka prefecture, excluding the Osaka city area, provided test kits to the guardians of infants who received a check-up at 18 months of age between 2004 and 2017. For patients whose standardized urinary levels of vanillylmandelic acid or homovanillic acid exceeded the threshold, they were further examined and treated in two specific hospitals Osaka University Hospital and Osaka Women's and Children's Hospital. Screening-positive patients with and without neuroblastoma were retrospectively reviewed. RESULTS: Among 142,423 children screened during the 18MS, 85 tested positive, and 14 were diagnosed with neuroblastoma. Twelve patients were classified as very low risk, while 2 were classified as high risk, based on the International Neuroblastoma Risk Group risk classification. CONCLUSION: The 18MS did not screen unfavorable cases with neuroblastoma efficiently, although few participants benefited from it.

Safety and Feasibility of Laparoscopic Resection of Neuroblastoma Without Image-Defined Risk Factors Performed by Pediatric Surgical Trainees: A Multicenter Comparison Study.

Introduction: Laparoscopic resection has gradually been adopted for neuroblastoma patients; however, some authors reported that, due to its technically demanding procedures, this operation should be performed only by highly experienced surgeons. The aim of this study was to evaluate the safety and feasibility of laparoscopic resection of abdominal neuroblastoma by pediatric surgical trainees. Subjects and Methods: In this multicenter, retrospective study, including 18 children with abdominal neuroblastoma indicated for 19 laparoscopic resections (1 with bilateral neuroblastomas) from 1999 to 2018, the clinical data were retrospectively reviewed and compared between trainee and attending surgeons. Results: None of the cases had image-defined risk factors (IDRFs) at surgery. All patients successfully underwent complete laparoscopic resection without blood transfusion, open conversion, or intraoperative or postoperative complications. Of the 19 cases, 6 were performed by pediatric surgical trainees under the guidance of attending surgeons, and 13 were performed by attending surgeons. With comparable tumor, largest diameter, operative time, and bleeding amount were not significantly different between the two groups. In the trainee surgeon group, one local recurrence occurred at a secondary resection site in the bilateral neuroblastoma patient with Stage L2. Conclusions: Laparoscopic resection of neuroblastoma could be safe and feasible when limited to absent IDRFs at surgery by pediatric surgical trainees under the guidance of experienced attending surgeons, as well as by attending surgeons.

Effect of microscopy-assisted portoenterostomy (MAPE) for biliary atresia.

PURPOSE: Portoenterostomy (PE) is the standard treatment for biliary atresia (BA). However, micro-bile ducts are difficult to identify with surgical loupes and dissect systematically. We report the effects of our attempts to dissect hilar tissue using a surgical microscope. METHODS: Microscopy-assisted portoenterostomy (MAPE) was initiated in 2014. Patients born between 2000 and 2013 who underwent PE until day 70 without a surgical microscope for BA were gathered as historical control. MAPE in re-do PE cases (Re-MAPE) was evaluated in the same manner. RESULTS: Ten patients underwent MAPE for BA during the study period. 17 patients in the conventional PE group were gathered. In the MAPE group, the jaundice clearance rate was 80%, compared with 53% in the conventional PE group. Re-MAPE was performed in four patients, who had a jaundice clearance rate of 75%, essentially identical to the rate with initial MAPE. At age 4 years, the native liver survival rate was 58% in the MAPE group and 38% in the conventional PE group. The native liver survival rate in the Re-MAPE group was 75%. CONCLUSION: MAPE is useful for sharing the surgical field during open PE in patients with BA. It may improve the rate of jaundice clearance.

Laparoscopic retroperitoneal splenopexy for wandering spleen: A novel technique using a three-incision retroperitoneal pouch.

INTRODUCTION: Wandering spleen is a rare condition for which splenopexy is indicated to prevent splenic torsion. We present a novel laparoscopic splenopexy technique for wandering spleen based on creation of a three-incision retroperitoneal pouch. MATERIALS AND SURGICAL TECHNIQUE: A 12-year-old male patient with abdominal distention and vomiting was transferred to our institution. Contrast-enhanced CT revealed a swollen wandering spleen with associated gastric volvulus, and the patient underwent laparoscopic surgery. A 5-mm camera port was inserted through an umbilical incision with two additional ports, one in the right upper abdomen and one in the left flank. Normal saline was injected into the retroperitoneal space from the left flank with a 23-G needle to create a retroperitoneal pouch. Three ventrodorsal peritoneal incisions were created at the same site in the peritoneum. The swollen spleen was inserted into the retroperitoneal pouch from the central incision, and the upper and lower poles of the spleen were exposed to the abdominal cavity from the cranial and caudal incisions to prevent splenic torsion. Finally, anterior gastropexy was performed. The postoperative period was uneventful. The patient was discharged on postoperative day 11 without complaints. As of 10 months after surgery, the patient had no recurrences of splenic torsion or gastric volvulus. DISCUSSION: In the present method, the retroperitoneal pouch was created without difficulty by injection of normal saline. Even in a patient with a swollen spleen, this novel method could prevent splenic torsion without using artificial materials or extensively dissecting the retroperitoneal space.

Can plain chest X-ray replace computed tomography for the follow-up of children who have undergone the Nuss procedure?

PURPOSE: To establish whether new indices on plain chest X-ray (CXR) can replace those on computed tomography (CT) for the follow-up of children who have undergone the Nuss procedure. METHODS: The subjects of this retrospective study were 45 children who underwent the Nuss procedure between 2000 and 2016. The Haller index (HI) was measured by preoperative CT. Preoperative and postoperative chest deformities were evaluated by two CXR measurements: the concave rate on the lateral view (CR; the depth of the concavity divided by the anterior-posterior diameter of the rib cage) and the tracheal bifurcation angle (TBA) on the anterior view. Data are expressed as the median with range. RESULTS: The median age and HI of the children, when they underwent the Nuss procedure, was 9.3 (3.8-17.3) years and 4.5 (3.2-10.1), respectively. The preoperative CR was correlated significantly with the HI. The postoperative CR was significantly lower than the preoperative CR [pre: 0.17 (0.08-0.37), post: 0.09 (0.01-0.18), p < 0.05], and the low value was sustained after bar removal. The TBA decreased significantly after the Nuss procedure from 74.2° (55-104) preoperatively to 65.0° (45-92) postoperatively (p < 0.05). CONCLUSIONS: These results suggest that CXR can replace CT for the follow-up of patients after the Nuss procedure, with lower radiation exposure.

Outcome and Late Complications of Hepatoblastomas Treated Using the Japanese Study Group for Pediatric Liver Tumor 2 Protocol.

PURPOSE: We report here the outcomes and late effects of the Japanese Study Group for Pediatric Liver Tumors (JPLT)-2 protocol, on the basis of cisplatin-tetrahydropyranyl-adriamycin (CITA) with risk stratification according to the pretreatment extent of disease (PRETEXT) classification for hepatoblastoma (HB). PATIENTS AND METHODS: From 1999 to 2012, 361 patients with untreated HB were enrolled. PRETEXT I/II patients were treated with up-front resection, followed by low-dose CITA (stratum 1) or received low-dose CITA, followed by surgery and postoperative chemotherapy (stratum 2). In the remaining patients, after 2 cycles of CITA, responders received the CITA regimen before resection (stratum 3), and nonresponders were switched to ifosfamide, pirarubicin, etoposide, and carboplatin (ITEC; stratum 4). Intensified chemotherapeutic regimens with autologous hematopoietic stem-cell transplantation (SCT) after resection were an optional treatment for patients with refractory/metastatic disease. RESULTS: The 5-year event-free and overall survival rates of HB patients were 74.2% and 89.9%, respectively, for stratum 1, 84.8% and 90.8%%, respectively, for stratum 2, 71.6% and 85.9%%, respectively, for stratum 3, and 59.1% and 67.3%%, respectively, for stratum 4. The outcomes for CITA responders were significantly better than those for nonresponders, whose outcomes remained poor despite salvage therapy with a second-line ITEC regimen or SCT. The late effects, ototoxicity, cardiotoxicity, and delayed growth, occurred in 61, 18, and 47 patients, respectively. Thirteen secondary malignant neoplasms (SMNs), including 10 leukemia, occurred, correlating with higher exposure to pirarubicin and younger age at diagnosis. CONCLUSION: The JPLT-2 protocol achieved up-front resectability in PRETEXT I/II patients with no annotation factors, and satisfactory survival in patients who were CITA responders in the remaining patients. However, outcomes for CITA nonresponders were unsatisfactory, despite therapy intensification with ITEC regimens and SCT. JPLT-2 had a relatively low incidence of cardiotoxicity but high rates of SMNs.

Liver resection for a congenital intrahepatic portosystemic shunt in a child with hyperammonemia and hypermanganesemia: a case report.

BACKGROUND: Congenital portosystemic shunt (CPSS) is a rare malformation that leads to hyperammonemia, hypermanganesemia, and various symptoms. CPSSs are divided into intrahepatic and extrahepatic shunts. In patients with persistent CPSS including an intrahepatic portosystemic shunt (IPSS), early intervention to occlude the shunt reverses the associated complications. CASE PRESENTATION: The patient was a 1-year-and-7-month-old girl. She presented with hypergalactosemia and elevation of blood ammonia level (75 µg/dL) and total bile acid levels (68.2 µmol/L) during the neonatal period. Two IPSSs were detected using ultrasound and enhanced computerized tomography. Magnetic resonance imaging (MRI) at 1 year and 3 months of age showed abnormally high signal intensity in the pallidum of her brain. Spontaneous closure was not observed. We performed a right hepatectomy at 1 year and 7 months of age. The portal vein pressure was 16 mmHg after temporary occlusion of the right portal vein. Blood ammonia and serum manganese levels decreased immediately after the operation. The abnormal signal on brain MRI disappeared. She had a favorable course with no sign of recurrence of IPSS 5 years postoperatively. CONCLUSION: Liver resection for an IPSS to control the symptoms of a portosystemic shunt is reasonable in a child for whom interventional radiological treatment is not indicated.

Thoracoscopic repair of esophageal atresia.

Thoracoscopic repair (TR) of esophageal atresia (EA) has been performed with increasing frequency over the last two decades, with the expectation of improved outcomes by avoiding thoracotomy. To understand the current practice and outcomes of TR of EA, we reviewed the relevant literature, including 15 case series, 7 comparative studies, and 3 meta-analysis comparing TR with conventional open repair (COR). Most of the studies had a retrospective design and small numbers of patients. Although the evidence level is low because of the lack of prospective studies, this review found that TR is as safe as COR, with comparative outcomes. Moreover, there were several advantages of TR over COR, such as less blood loss and a shorter hospital stay. The long-term outcomes of TR remain unclear because of limited data. Moreover, there is a significant learning curve over the first 10-20 TRs performed. We conclude that TR of EA, when conducted by experienced surgeons, is a safe and minimally invasive alternative to COR and may yield better results than COR in appropriately selected patients.

The effect of a novel immunosuppressive drug, a PAK-2 inhibitor, on macrophage differentiation/polarization in a rat small intestinal transplantation model.

OBJECTIVE: PQA-18 (Prenylated quinolinecarboxylic acid-18) has been reported to be a novel immunosuppressant that attenuates the production of various cytokines, and the differentiation of macrophages by inhibiting PAK2. In this study, we investigated the function of this drug mainly on macrophages using a rat small intestinal transplant model. METHODS: Male Dark Agouti (DA) and Lewis rats (LEW), 7-9 weeks of age, were used as donor and recipient, respectively. Approximately 15 cm intestinal grafts were heterotopically transplanted to the recipient rats. The recipient rat was treated with PQA-18 (4 mg/kg/day) by intraperitoneal injection (ip) from postoperative day 1 for 2 weeks. The in vivo effects of this drug were evaluated based on changes in body weight, and the population of each type of blood cell. Mixed lymphocyte reaction (MLR) was also assessed, using the T cells from intestinal mesenteric lymph nodes (MLN) of the grafts on POD6. Total cells from MLN and graft Payer's patch (PP) were next collected on POD6, and the number of infiltrated macrophages was determined. RESULTS: While the survival time was 7.0 ±â€¯0.77 days for the control group (n = 9), that for the PQA-18 group was 10.7 ±â€¯1.26 days (n = 10) (p < .001). Histological examinations showed a relatively clear difference in the grafts for both groups. In addition, the MLR response was significantly lower in recipients treated with PQA-18, suggesting PQA-18 well suppressed the T cells. Moreover, while a significant increase of both MHC class II and CD11b/c positive cells, estimated as differentiated/polarized macrophages, in MLN & PP was observed in the control group, PQA-18-administration significantly suppressed the differentiation of macrophages in the MLN & PP. CONCLUSION: PQA-18 significantly prolonged the survival of the rats with intestinal grafts, and also suppressed the infiltration of lymphocytes, and macrophages to the grafts.

Serum Mac-2-binding protein (M2BPGi) as a marker of chronological liver fibrosis in biliary atresia patients with cirrhosis.

PURPOSE: Biliary atresia (BA) is characterized by progressive liver fibrosis, but it is difficult to assess the progression after the patient develops cirrhosis. Mac-2-binding protein glycosylation isomer (M2BPGi) is a new marker for hepatic fibrosis. We examined the chronological changes in M2BPGi levels in BA patients with cirrhosis. METHODS: Patients with cirrhosis were selected from among pediatric BA patients who had their native livers. Serum M2BPGi levels and Child-Pugh classification were evaluated. A total of 11 pediatric BA patients with cirrhosis were recruited. RESULTS: Initial M2BPGi level after diagnosis of liver cirrhosis based on liver biopsy was on average 3.4, and the most recent M2BPGi level under observation was on average 4.3. The follow-up period from the initial M2BPGi measurement averaged 22.6 months. The ratio of the initial and most recent values (M2BPGi ratio) was on average 1.3 (0.5-2.4). Three cases with improved fibrosis (M2BPGi ratio < 1.0) remained in Child A, as did six cases (1.0 ≤ M2BPGi ratio < 2.0), but two cases with marked fibrosis progression (2.0 ≤ M2BPGi ratio) advanced to decompensated cirrhosis Child B. CONCLUSION: M2BPGi is useful as a prognostic factor for BA patients with liver cirrhosis. In addition, fibrosis improved even after the development of cirrhosis.

Recombinant human soluble thrombomodulin reduces the severity and incidence of necrotizing enterocolitis in a newborn rat model.

PURPOSE: Necrotizing enterocolitis (NEC) remains the leading cause of death in preterm infants. Recombinant human soluble thrombomodulin (rTM) has been reported to have anti-inflammatory effects as well as antithrombogenic effects. The aim of this study was to evaluate the effect of rTM in a rat NEC model. METHODS: NEC was induced by enteral feeding with hyperosmolar formula, gavage administration of lipopolysaccharide and asphyxia stress. Controls were fed by their mother ad libitum. In the treatment group, rTM was administered subcutaneously twice (once each on the first and second day). All animals surviving beyond 96 h or that developed signs of distress were euthanized. The ileum was harvested for a histological evaluation and the measurement of the mRNA and protein expression. RESULTS: The rate of NEC-like intestinal injury in the treatment group (9/25, 36%) was significantly lower than in the NEC group (25/34, 73.5%). Tissue levels of TNF-α, IL-6 and HMGB1 were significantly elevated in the NEC group, whereas those in the treatment group were decreased to similar values as in the control group. CONCLUSIONS: Our experimental study showed that rTM is able to reduce the severity and incidence of NEC. It may be an alternative option for the treatment of NEC.

The effect of maternal grafts in early acute cellular rejection after pediatric living-donor liver transplantation.

PURPOSE: Living-donor liver transplantations (LDLTs) with maternal grafts can be more successful than those with paternal grafts because of their tolerance to non-inherited maternal antigens. We reviewed LDLT patients to investigate the relationship between acute rejection and donor sex. METHODS: LDLT patients between January 2010 and November 2015 were enrolled. ACR was defined by a rejection activity index of > 3. RESULTS: Forty-six patients (22 males and 24 females), of whom 28 had biliary atresia, were enrolled. The median age of the patients was 2.8 years and the donor types were maternal (n = 25) and paternal (n = 21). Acute cellular rejection (ACR) was observed in 22 patients. Twelve (48%) of the 25 patients in the maternal group had at least one episode of rejection compared with 10 (48%) of the 21 in the paternal group. Among the patients with ACR, the first rejection in the maternal group occurred significantly earlier than that in the paternal group (p < 0.01). In the multivariable analysis, the only variable significantly related to the first rejection day after LDLT was donor sex (male) (p < 0.005). CONCLUSION: Our results showed that maternal grafts had an effect on causing earlier ACR in LDLT.

Long-term outcomes of patch tracheoplasty using collagenous tissue membranes (biosheets) produced by in-body tissue architecture in a beagle model.

PURPOSE: Although various artificial tracheas have been developed, none have proven satisfactory for clinical use. In-body tissue architecture (IBTA) has enabled us to produce collagenous tissues with a wide range of shapes and sizes to meet the needs of individual recipients. In the present study, we investigated the long-term outcomes of patch tracheoplasty using an IBTA-induced collagenous tissue membrane ("biosheet") in a beagle model. METHODS: Nine adult female beagles were used. Biosheets were prepared by embedding cylindrical molds assembled with a silicone rod and a slitting pipe into dorsal subcutaneous pouches for 2 months. The sheets were then implanted by patch tracheoplasty. An endoscopic evaluation was performed after 1, 3, or 12 months. The implanted biosheets were harvested for a histological evaluation at the same time points. RESULTS: All animals survived the study. At 1 month after tracheoplasty, the anastomotic parts and internal surface of the biosheets were smooth with ciliated columnar epithelium, which regenerated into the internal surface of the biosheet. The chronological spread of chondrocytes into the biosheet was observed at 3 and 12 months. CONCLUSIONS: Biosheets showed excellent performance as a scaffold for trachea regeneration with complete luminal epithelium and partial chondrocytes in a 1-year beagle implantation model of patch tracheoplasty.

Postoperative decrease in plasma acyl ghrelin levels after pediatric living donor liver transplantation in association with hepatic damage due to ischemia and reperfusion injury.

PURPOSE: Ghrelin was recently reported to promote recovery from hepatic injury. We hypothesized that it could also be associated with clinical recovery of the transplanted liver from ischemia and reperfusion injury. Our aims were to investigate perioperative ghrelin changes following pediatric living donor liver transplantation (LDLT) and to analyze the association of these changes with postoperative hepatic function. METHODS: We measured plasma acyl ghrelin (AG) concentrations before surgery, at the end of surgery and on postoperative days (PODs) 1, 3 and 7 in 12 children who underwent LDLTs, and, as controls, pre- and post-operatively and on POD1 in 7 children who underwent benign abdominal mass resection. The correlations between the participants' ghrelin profiles and hepatic function-related data were evaluated. RESULTS: AG levels significantly declined to 15.6% of preoperative levels after LDLT and almost returned to baseline on POD3. Post-operative AG levels were significantly reduced to a greater extent following LDLT than benign abdominal mass resection. AG levels on POD1 inversely correlated with aspartate aminotransferase levels and cold/total ischemia time (P < 0.05). CONCLUSION: These results suggest that reduced AG levels on POD1 may reflect the degree of damage to the transplanted liver due to ischemia and reperfusion injury.

Tracheal Replacement Using an In-Body Tissue-Engineered Collagenous Tube "BIOTUBE" with a Biodegradable Stent in a Beagle Model: A Preliminary Report on a New Technique.

INTRODUCTION: Tracheal reconstruction for long-segment stenosis remains challenging. We investigate the usefulness of BIOTUBE, an in-body tissue-engineered collagenous tube with a biodegradable stent, as a novel tracheal scaffold in a beagle model. MATERIALS AND METHODS: We prepared BIOTUBEs by embedding specially designed molds, including biodegradable stents, into subcutaneous pouches in beagles. After 2 months, the molds were filled with ingrown connective tissues and were harvested to obtain the BIOTUBEs. The BIOTUBEs, cut to 10- or 20-mm lengths, were implanted to replace the same-length defects in the cervical trachea of five beagles. Endoscopic and fluoroscopic evaluations were performed every week until the lumen became stable. The trachea, including the BIOTUBE, was harvested and subjected to histological evaluation between 3 and 7 months after implantation. RESULTS: One beagle died 28 days after 20-mm BIOTUBE implantation because of insufficient expansion and retention force of the stent. The remaining four beagles were implanted with a BIOTUBE reinforced by a strong stent, and all survived the observation period. Endoscopy revealed narrowing of the BIOTUBEs in all four beagles, due to an inflammatory reaction, but patency was maintained by steroid application at the implantation site and balloon dilatation against the stenosis. After 2 months, the lumen gradually became wider. Histological analyses showed that the internal surface of the BIOTUBEs was completely covered with tracheal epithelial cells. CONCLUSION: This study demonstrated the usefulness of the BIOTUBE with a biodegradable stent as a novel scaffold for tracheal regeneration.

Laparoscopic ligation of a congenital extrahepatic portosystemic shunt for children with hyperammonemia: a single-institution experience.

PURPOSE: A congenital extrahepatic portosystemic shunt (CEPS) associated with hyperammonemia requires occlusion of the shunt vessels. We evaluated the effectiveness and safety of laparoscopic ligation of a CEPS in children with hyperammonemia. METHODS: The subjects of this retrospective study were seven children with hyperammonemia who underwent laparoscopic ligation of a CEPS. Their median age was 5.2 years (range 1-16 years). Before the laparoscopic procedure, a catheter was inserted through the femoral vein and placed in the portal vein via the shunt vessel. The shunt vessel was dissected and taped laparoscopically. After measuring the portal vein pressure under temporal occlusion, the shunt vessels were ligated. RESULTS: The types of shunts according to location were patent ductus venosus (n = 2), splenorenal shunt (n = 2), gastrorenal shunt (n = 2), and superior mesenteric vein-inferior vena cava shunt (n = 1). Laparoscopic ligation of the shunt vessel was completed uneventfully in all patients. The median portal vein pressure was 19 mmHg after ligation. The median preoperative blood ammonia level was 94 µg/dL (range 71-259 µg/dL), which decreased after ligation in all patients. There was no incidence of postoperative liver failure. CONCLUSION: Laparoscopic ligation of a CEPS is safe and effective for children with hyperammonemia.