Abstract: Brachytherapy has many potential roles in cancer therapy. However, major constraints are associated with placement and removal procedures of the brachytherapy machinery. An attractive approach would be the use of a biodegradable implant loaded with a radioisotope, thus enabling targeted radiotherapy, while reducing the need for surgical procedures for the removal of brachytherapy hardware. In this study, crosslinked chitosan (Ct) hydrogels were prepared and loaded with (131)I-norcholesterol ((131)I-NC). The radioactive hydrogels ((131)I-NC-Ct) were implanted adjacent to 4T1 cell-induced tumors in two different xenograft mice models either as primary therapy or surgical adjuvant therapy of breast cancer. Non-treated mice and mice implanted with naive (non-radioactive) hydrogels served as control groups. In the primary therapy model, the progression rate of the tumor was delayed by two weeks compared with the non-treated and the naive-implant control animals, resulting in a one-week extension in the survival of the treated animals. In the adjuvant therapy model, for the treatment of minimal residual disease, (131)I-NC-Ct implants were able to prevent 69% of tumor recurrence, and to prevent metastatic spread resulting in long-term survival, compared with 0% long-term survival of the non-treated and the naive control groups. Imaging of the hydrogel's in vivo elimination revealed a first order process with a half-life of 14 days. The degradation was caused by oxidation of the Ct as was assessed by in vitro H&E stain. Biodegradable radioactive implants are suggested as a novel platform for the delivery of brachytherapy. This radiotherapy regimen may prevent locoregional recurrence and metastatic spread after tumor resection.

Abstract: The aim of the present study was to evaluate the toxicity of biodegradable hydrogels in the rat with a future aim of utilizing this hydrogel as a vehicle for brachytherapy delivery in cancer patients. Two types of chitosan hydrogels: fast degrading and slow degrading; were prepared and surgically implanted in rats. The adjacent tissue response to the gels after subcutaneous and intraperitoneal implantation was examined histologically and found to be identical to typical foreign body response and was milder than the response to absorbable surgical sutures (Vicril). Neither tissue damage nor gel fragments could be detected in distant organs (brain, heart, lungs, liver, spleen, kidney, and sternal bone marrow) after implantation of the hydrogels. The degradation mechanism of the gels was studied in vivo, and it was deduced that an oxidative process degraded the chitosan. Loading the hydrogels with a radioisotope (131I-norcholesterol) caused a severe tissue response and necrosis in adjacent tissues only at a distance of several microns. It is concluded that crosslinked chitosan implants could serve as alternative, biocompatible, and safe biodegradable devices for radioisotope delivery in brachytherapy for cancer.

Abstract: BACKGROUND: The approach for treating contralateral pediatric inguinal hernias is still controversial. The options are delaying surgery on the contralateral side, automatic exploration, diagnostic laparoscopy through the ipsilateral hernia sac or laparoscopic repair. In children younger than 6 months, occult bilateral hernia is more prevalent, and the hernia sac is difficult for laparoscopic manipulation. We present our early experience with transabdominal laparoscopic hernia repair in infants younger than 6 months of age. METHODS: Thirty four infants younger than 6 months and presenting with unilateral inguinal hernia were operated laparoscopically through a transabdominal approach. Patients were followed for a median of 11 months. RESULTS: Thirty three of the operations were completed laparoscopically. There was a 38.2% incidence of occult bilateral hernia. There were 3 recurrences due to a technical mistake (6.4%), one minor operative complication (needle lost and retrieved) and one minor anesthetic complication (prolonged intubation). In one operation a mini laparotomy was performed to retrieve a needle that was disengaged whilst removed from the abdomen. CONCLUSIONS: Laparoscopic hernia repair is feasible in young infants. It may be particularly suitable for children younger than 6 months. Further studies are needed to assess long-term results.

Abstract: Compared with conventional external beam radiation, brachytherapy offers a superior therapeutic regimen. However, some major constraints are associated with its implementation, including the need of complicated procedures for device placement and removal. The purpose of this study was to examine whether crosslinked chitosan (Ct) implants could serve as potential biodegradable devices for brachytherapy. Ct was reacted with increasing amounts of glutaraldehyde to obtain hydrogels with different crosslinking densities, which were characterized chemically, thermally and mechanically. The effect of the dialysis medium conditions (ionic strength, osmolarity and pH) on the gel hydration and in vivo degradation was assessed. Two types of implants, slow and fast degrading gel (SDG and FDG, respectively), were prepared and implanted with or without Sudan Black (SB) in the rat. While SDG withstood for over a month, the FDG degraded within two weeks after implantation. The release kinetics of SB from the hydrogels verified their in vivo degradation properties. The incorporation of the radioactive compound (131)I-norcholesterol ((131)I-NC) into the SDG altered the degradation kinetics of the gel as reflected by the release kinetics of the radioactive marker. Eighty percent of (131)I-NC was released within a month after implantation, after which time, radioactivity was detected in the regional lymph nodes. Histological examination of the tissues surrounding the implants demonstrated negligible tissue response to the implants, when compared to biodegradable surgical sutures. It is concluded that hydrogels made of crosslinked Ct are potential novel, safe, degradable devices for brachytherapy.

Abstract: Imperforate anus and malrotation rarely occur together. The conjoint occurrence of these with Hirschsprung's disease is exceedingly rare, but failure to recognize its existence may lead to catastrophic results. We present a case in which awareness to this possibility caused early detection and avoidance of possible complications.

Abstract: We present the case of a premature baby who was born with the following conditions: an extensive atresia from the first part of the duodenum to the mid small bowel; malrotation of the distal part, in volvulus and in an "apple peel" configuration; no connection of the bile ducts to the bowel; and presence of a type II choledochal cyst. To our knowledge, this is the first case in which a combination of these anomalies is reported. A brief review of the relevant literature is also presented.