BACKGROUND: Platelet-rich plasma containing various high-concentration growth factors can promote new bone formation and accelerate bone healing. But its effects on distraction osteogenesis remain unclear. OBJECTIVE: To observe the effects of autologous platelet-dch plasma on premaxillary distraction osteogeaesis in rabbits. DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Laboratory of Physiology, North Campus,Sun Yat-sen University between July and August 2007. MATERIALS: Sixteen healthy rabbits, the same number for male and female, aged 3-5 months,weighing 1. 4-1.7 kg,were randomly and evenly divided into an experimental group and a control group. Premaxillary incisor band,outside front distraction mask, and distraction rubber band were self-made.Coagulant was prepared by dissolving 1000 u bovine thrombin in 1 mL of 10% calcium chloride.METHODS: Titanium nails (1.5 mm in diameter) were separately inserted on two sides of left premaxillary suture in rabbits. A self-made distraction device was used. Gelatum-like substance [Vplatelet-rich plasma: V coagulant=9:1] was injected into the left premaxillary suture of experimental group rabbits immediately prior to distraction.In each group, one-week sustained distraction was performed in 4 rabbits,and three-week sustained distraction was performed in another rabbits. MAIN OUTCOME MEASURES: The increase of nail-nail distance on the two sides and histological results following distraction osteogenesis.RESULLTS: Rabbit premaxillary bone moved anterior in the two groups. The experimental group showed greater increase of nail-nail distance, faster bone formation and mineralization, more blood vessels, and thicker and more mature bone trabecula in the distraction interspace in comparison with the control group. CONCLUSION: Platelet-rich plasma will help bone tissue regeneration and promote premaxillary distraction osteogenesis.

OBJECTIVETo evaluate the efficacy of self-made gasbag double-cannula stool drainage device for prevention of anastomotic leakage following anterior resection.

METHODSClinical data of 169 rectal cancer patients in the 8th Affiliated Hospital of Sun Yat-sen University between October 2010 and October 2016 were retrospectively analyzed. Among them, a self-made gasbag double-cannula stool drainage device was placed in 71 patients(stool drainage group), and the remaining 98 patients were taken as control. After an anastomosis, the drainage device was transanally placed by the assistant and the distal tube of drainage device was stretched more than 15 cm from anastomosis. The gasbag was inflated to fully expand the intestine. The main tube was fixed on perianal skin with 7-0 suture, kept more than 3-5 cm outside the anus, and connected to the drainage bag. The incidence of anastomotic leakage was compared between the two groups.

RESULTSThe baseline data were similar between the two groups (all P>0.05). The differences in operative time, intraoperative blood loss, and time to bowel function recovery were not statistically significant (all P>0.05), however, time to oral intake and postoperative stay were shorter in stool drainage group as compared to the control group (both P<0.05). There was no perioperative death in both groups. In stool drainage group, there were 6 cases whose drainage device was pulled out within 48 hours due to intolerance. The ruptured gasbag was replaced 5 times and the tube was clogged by fecal material 21 times. After flushing, the tube did not recanalized and was pulled out in 3 cases. The incidence of anastomotic leakage in stool drainage group was significantly lower than that in the control group (2.8% vs. 11.2%, P=0.043). As for the low anastomosis (the distance to anal verge less than 5 cm), the incidence of anastomotic leakage in stool drainage group was also significantly lower than that in the control group (2.3% vs. 15.4%, P=0.028), while as for the high anastomosis, the difference was not statistically significant (3.6% vs. 3.0%, P=0.906). Logistic regression analysis revealed that the presence of a stool drainage device was an independent protective factor for anastomotic leakage (OR=0.316, 95%CI:0.114 ~ 0.769, P=0.003).

CONCLUSIONSThe self-made gasbag double-cannula stool drainage device effectively prevents anastomotic leakage after anterior resection of rectal cancer. However it is not suitable for those patients with high anastomosis.

Objective To preliminarily evaluate the application value of SpyGlass direct visualization system in the diagnosis and treatment of biliary stricture after liver transplantation. Methods Clinical data of 4 patients presenting with biliary stricture after liver transplantation who underwent SpyGlass direct visualization system examination were collected. The examination, treatment and prognosis of biliary stricture were analyzed. Results The examination results of color Doppler ultrasound, magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) in 4 patients suggested biliary anastomotic stricture with intrahepatic biliary dilatation, and 2 of them were complicated with intrahepatic biliary calculi. Repeated placement of biliary stent under ERCP yielded poor effect in 3 cases. SpyGlass direct visualization system examination hinted biliary anastomotic stricture in 4 patients, 3 cases of intrahepatic biliary dilatation, 3 cases of intrahepatic biliary calculi, 2 cases of purulent bile and 3 cases of floccules within the biliary tract, 1 case of congestion and edema of biliary tract wall and 2 cases of local epithelial necrosis and stiffness changes of intrahepatic biliary tract wall. The wire could not be inserted in 1 patient due to severe biliary anastomotic stricture. Four patients were treated with biliary stricture resection + biliary stone removal + biliary end-to-end anastomosis, biliary stricture resection + biliary-intestinal anastomosis, ERCP lithotomy + biliary metal stent implantation, and biliary metal stent implantation + percutaneous transhepatic bile duct lithotomy, respectively. Relevant symptoms were relieved without evident complications. All patients survived during the follow-up until the submission date. Conclusions Compared with traditional imaging examination, SpyGlass direct visualization system may more directly display the morphological characteristics of biliary tract wall and structural changes within biliary tract cavity, which is an effective examination tool for biliary stricture after liver transplantation. In addition, individualized treatment methods may be adopted for different biliary tract diseases, which is expected to improve clinical prognosis of patients.