Hiroshi Kawashima

An animal model study for tissue-engineered trachea fabricated from a biodegradable scaffold using chondrocytes to augment repair of tracheal stenosis

INTRODUCTION We have designed an engineered graft fabricated from a biodegradable scaffold using chondrocytes and applied this construct to augment repair of tracheal stenosis. This study investigated the feasibility of using such tissue-engineered airways with autologous chondrocytes in a rabbit model. MATERIAL AND METHODS Chondrocytes were isolated and expanded from the auricular cartilage of New Zealand white rabbits, then seeded onto composite 3-layer scaffolds consisting of a collagen sheet, a polyglycolic acid mesh, and a copolymer (l-lactide/epsilon-caprolactone) coarse mesh. The engineered grafts were implanted into a 0.5 x 0.8-cm defect created in the midventral portion of the cervical trachea. Gelatin sponges that slowly released basic fibroblast growth factor (b-FGF) were then placed on the constructs, which were retrieved 1 or 3 months after implantation. RESULTS The biodegradable scaffold seeded with chondrocytes could maintain airway structure up to 3 months after implantation. Tracheal epithelial regeneration occurred in the internal lumen of this composite scaffold. Three months after implantation, staining of the sections showed cartilage accumulation in the engineered tracheal wall. CONCLUSION This composite biodegradable scaffold may be useful for developing engineered trachea. A gelatin sponge slowly releasing b-FGF might enhance chondrogenesis.

Long-term outcomes of operative versus nonoperative treatment for uncomplicated appendicitis

PURPOSE Although nonoperative treatment for uncomplicated appendicitis is now an accepted approach, there are few reports in children. The aim of this study was to compare long-term outcomes between operative and nonoperative treatment in children. METHODS Between April 2007 and December 2013, all uncomplicated appendicitis patients were asked to select either operative (laparoscopic surgery) or nonoperative treatment on admission. For nonoperative treatment, intravenous injection of antibiotics was continued until serum C-reactive protein concentration decreased to below 0.5mg/dL. A questionnaire survey on satisfaction with treatment was added afterwards and performed more than 1year after treatment. RESULTS Eighty-six patients chose operative treatment, and 78 chose nonoperative treatment. The success rate of nonoperative treatment was 98.7%. There was no difference in the length of hospital stay between the two groups. Ileus occurred in two operatively-treated patients, while recurrence of appendicitis occurred in 22 nonoperatively-treated patients (28.6 %) after an average of 4.3years of follow-up. The overall nonoperative treatment failure including both early failure and recurrence occurred more frequently among those with appendicoliths than without appendicoliths. Satisfaction levels were higher for operative treatment. CONCLUSIONS Although the success rate of nonoperative treatment was very high, a considerable number of patients experienced recurrence.

Endosurgical procedures for pediatric solid tumors

The aim of this study was to evaluate the advantages and complications of endosurgical procedures for benign and malignant pediatric solid tumors. Endosurgical techniques of biopsy and excision were used for diagnosis and treatment of solid tumors, respectively. Since July 1997, a total of 24 biopsies and 24 excisions have been performed laparoscopically for neuroblastoma (n=24), ovarian solid tumors (n=10) and other tumors. Seventeen biopsies and six excisions were performed for abdominal neuroblastoma, while ten excisions were performed for ovarian tumor. In these patients, the length of the operation, blood loss, time to start postoperative feeding, time to start postoperative chemotherapy and length of hospital stay were evaluated and compared to the those of the open surgery group. Furthermore, intra- and postoperative complications were analyzed in all patients of both groups. The length of the hospital stay and time to start postoperative feeding were significantly shorter in the group of patients who underwent endosurgical procedures for either abdominal neuroblastoma or ovarian tumor when compared to the open procedure group. The time to start postoperative chemotherapy was shorter only in the abdominal neuroblastoma group. The procedure for two patients undergoing endosurgical tumor excision had to be converted to open surgery due to large tumor size. Two weeks after thoracoscopic excision of a dumb bell-type neurofibroma, one patient underwent open repair of the dura mater because of leakage of cerebrospinal fluid. There were no port-site recurrences in any tumor types. Endosurgical procedures for solid tumors are effective and minimally invasive. However, better indicators are needed for their implementation in order to prevent complications and subsequent conversions to open procedures.

Surgical treatment for abdominal neuroblastoma in the laparoscopic era

Background: The role of laparoscopy in children with cancer has not been fully defined. The aims of this study were to develop an optimal surgical procedure for the treatment of abdominal neuroblastoma in the laparoscopic era and to evaluate the advantages and disadvantages of laparoscopy in the pediatric population. Methods: Since July 1997, 37 children were diagnosed with abdominal neuroblastoma at our center, and 44 surgical procedures were performed on them. Patients with advanced neuroblastoma underwent laparoscopic biopsy, open biopsy, and delayed primary or second-look excision, whereas early neuroblastoma cases had either laparoscopic or open excision. We compared the length of the operation, intraoperative blood loss, length of hospital stay, complications, and time to start postoperative feeding and chemotherapy for the laparoscopic and open surgery groups. Results: Length of stay and time to postoperative feeding and chemotherapy were significantly lower in the laparoscopic group than the open surgery group. However, there were no significant differences between the two groups in length of operation and intraoperative blood loss. Conclusion: Laparoscopic biopsy and excision of abdominal neuroblastoma are effective and efficient surgical procedures in children.

Findings of pelvic musculature and efficacy of laparoscopic muscle stimulator in laparoscopy-assisted anorectal pull-through for high imperforate anus

Background: Laparoscopic findings of levator muscle and the efficacy of laparoscopic muscle stimulator (LMS) in infants with high imperforate anus have not been reported. Methods: Twelve patients underwent laparoscopically assisted anorectoplasty for high imperforate anus. Following laparoscopic dissection of the distal rectum and division of the fistula, levator muscles in the pelvic floor were stimulated with a 5-mm-diameter LMS. Dilatation was done by inserting a guidewire and balloon catheter through the center of the levator muscle sling and muscle complex. Rectal pull-through and anastomosis between the rectum and anus were successfully completed. Results: LMS showed good contraction of levator muscles and enhanced accurate midline placement of pull-through rectum. LMS was particularly useful in observing weak muscles in infants with rectovesical fistula. Conclusions: Laparoscopy and LMS offer excellent visualization of the pelvic musculature and precise tract of rectal pull-through. Fecal continence will be assessed by long-term follow-up.

Inguinal hernia repair in children using single-incision laparoscopic-assisted percutaneous extraperitoneal closure

BACKGROUND/PURPOSE There are numerous techniques of minimally invasive surgery for pediatric inguinal hernia. However, laparoscopic percutaneous extraperitoneal closure (LPEC) is one of the most simple and reliable methods. Single-incision laparoscopic surgery has recently been developed to reduce the invasiveness of traditional laparoscopy. This study aimed to assess the safety and feasibility of the single-incision approach for LPEC. MATERIALS AND METHODS Between June 2009 and March 2010, 117 conventional LPEC and 60 single-incision LPEC (SILPEC) procedures were performed. A laparoscope was placed through a transumbilical incision. A 3-mm grasping forceps was inserted in the lower abdomen in LPEC and through the same transumbilical incision with a different entrance in SILPEC. Using the LPEC needle, the hernia sac was closed extraperitoneally. We compared the short-term outcomes of 177 children operated on using either technique. RESULTS Visualization and tissue manipulation were good in both methods. There were no complications or evidence of early recurrence. Cosmetically, SILPEC proved to be superior to LPEC because the scar resulting from surgical incision is hidden within the umbilicus. CONCLUSION Single-incision LPEC proved to be as successful an operative procedure as LPEC and produced excellent cosmetic results. Single-incision LPEC for inguinal hernia in children is safe and feasible.

Laparoscopic surgery in neonates and infants weighing less than 5 kg

Background : Laparoscopic surgery in small infants is still an uncommon procedure in Japan. The present study was conducted to evaluate the advantages and disadvantages of laparoscopic surgery in neonates and infants weighing less than 5 kg.

Single-incision laparoscopic-assisted appendectomy in children: exteriorization of the appendix is a key component of a simple and cost-effective surgical technique

PurposeSingle-incision laparoscopic appendectomy was recently introduced as a less-invasive surgical technique than existing methods, and is increasingly being performed worldwide. We have started to perform transumbilical laparoscopic-assisted appendectomy (TULAA) in children. In this study, we assessed its feasibility, efficacy, and cost-effectiveness compared with conventional multiport laparoscopic appendectomy (MLA).MethodsWe retrospectively reviewed all of the patients who underwent MLA or TULAA between August 2009 and December 2012. Patient characteristics, operative time, length of hospital stay, postoperative complications, cost-effectiveness, and cosmetic results were analyzed.ResultsA total of 88 patients underwent laparoscopic appendectomy, with MLA in 48 patients and TULAA in 40 patients. TULAA was successful in 36/40 patients. There were no significant differences in mean operative time or mean length of stay between the two groups of patients. There were no postoperative complications in the TULAA group. The cost of TULAA was much lower than that of MLA. TULAA also provided nearly scarless surgery.ConclusionTULAA, in which the appendix is exteriorized via a combination of open and laparoscopic techniques, is a safe and effective procedure for treating appendicitis in children. TULAA is a cost-effective treatment that provides excellent cosmetic results.

Low Frequency of Programmed Death Ligand 1 Expression in Pediatric Cancers.

Programmed death 1 (PD‐1)/programmed death ligand 1 (PD‐L1) pathway blockade has become a promising therapeutic target in adult cancers. We evaluated PD‐L1 expression and tumor‐infiltrating CD8+ T cells in formalin‐fixed, paraffin‐embedded tumor specimens from 53 untreated pediatric patients with eight cancer types: neuroblastoma, extracranial malignant germ cell tumor, hepatoblastoma, germinoma, medulloblastoma, renal tumor, rhabdomyosarcoma, and atypical teratoid/rhabdoid tumor. One rhabdomyosarcoma with the shortest survival exhibited membranous PD‐L1 expression and germinoma contained abundant tumor‐infiltrating CD8+ T cells and PD‐L1‐positive macrophages. The PD‐1/PD‐L1 pathway tended to be inactive in pediatric cancers.

Laparoscopic spleen-preserving distal pancreatectomy for solid pseudopapillary tumor with conservation of splenic vessels in a child

Laparoscopic spleen-preserving distal pancreatectomy (LSDP) with conservation of the splenic vessels is gaining acceptance as a reliable treatment for selected patients with low-grade malignant tumors of the pancreas in adults. The operation requires advanced laparoscopic skills to safely divide the fine branches of the splenic vessels. Laparoscopic spleen-preserving distal pancreatectomy with conservation of splenic vessels is rarely reported in children. We describe a 12-year-old girl with solid pseudopapillary tumor in the body of the pancreas that was successfully treated with LSDP, preserving the splenic vessels. The postoperative course was uneventful, and the functional and aesthetic results were satisfactory. Laparoscopic spleen-preserving distal pancreatectomy with conservation of splenic vessels may be a safe and feasible treatment option for children with pancreatic disease.