Enhanced Intrafibrillar Mineralization of Collagen Fibrils Induced by Brushlike Polymers.

Biomimetic mineralization of collagen fibrils is an essential process because the mineralized collagen fibers constitute the basic building block of natural bone. To overcome the limited availability and high cost of the noncollagenous proteins (NCPs) that regulate the mineralization process of collagen, commercially available analogues were developed to replicate sequestration and templating functions of NCPs. The use of branched polymers in intrafibrillar mineralization applications has never been explored. In this work, two novel carboxyl-rich brushlike polymers, a carboxylated polyethylene glycol terpolymer (PEG-COOH) and a polyethylene glycol/poly(acrylic acid) copolymer (PEG-PAA), were synthesized and modified to mimic the sequestration function of NCPs to induce intrafibrillar mineralization of collagen fibrils. It was found that these synthetic brushlike polymers are able to induce intrafibrillar mineralization by stabilizing the amorphous calcium phosphate (ACP) nanoprecursors and subsequently facilitating the infiltration of ACP into the gap zone of collagen microfibrils. Moreover, the weight ratios of mineral to collagen in the mineralized collagen fibrils in the presence of these brushlike polymers were 2.17 ± 0.07 for PEG-COOH and 2.23 ± 0.03 for PEG-PAA, while it is only 1.81 ± 0.21 for linear PAA. Plausible mineralization mechanisms using brushlike polymers are proposed that offer significant insight into the understanding of collagen mineralization induced by synthetic NCP analogues.

Randomized controlled trial of laparoscopic anterior 180° partial versus posterior 270° partial fundoplication.

BACKGROUND: Previous trials show good outcomes following anterior and posterior partial versus Nissen fundoplication for gastro-oesophageal reflux. However, it is unclear which partial fundoplication performs best. This study compared anterior 180° versus posterior 270° fundoplication. METHODS: At three hospitals, patients were randomized to anterior 180° versus posterior 270° partial fundoplication, and clinical outcomes were determined using a structured questionnaire at 3, 6 and 12 months. Heartburn, dysphagia and satisfaction were assessed using 0-10 analoue scales, and adverse outcomes and side effects were determined. Endoscopy, manometry and pH monitoring were performed 6 months after surgery. RESULTS: Forty-seven patients were randomized to anterior (n = 23) versus posterior (n = 24) fundoplication. Clinical outcomes for 93-98% of patients were available at each follow-up point. At 12 months, the mean heartburn score was higher following anterior fundoplication (2.7 versus 0.8, P = 0.045), although differences were not significant at earlier follow-up. Conversely, following posterior fundoplication, patients were less able to belch at 3 (56% versus 16%, P = 0.013) and 6 months (43% versus 9%, P = 0.017). No significant differences were demonstrated for dysphagia. Both groups had high rates of satisfaction with the outcome - 85% versus 86% satisfied at 12 months follow-up. CONCLUSION: Both partial fundoplications are effective treatments for gastro-oesophageal reflux. Posterior partial fundoplication is associated with less reflux symptoms offset by more side effects.

Five-year follow-up of a multicenter, double-blind randomized clinical trial of laparoscopic Nissen vs anterior 90 degrees partial fundoplication.

HYPOTHESIS: Laparoscopic 90 degrees anterior partial fundoplication for gastroesophageal reflux disease achieves equivalent results to laparoscopic Nissen fundoplication. DESIGN: A multicenter, prospective, double-blind randomized clinical trial with a minimum of 5 years' follow-up. SETTING: Nine university teaching hospitals in 6 major cities throughout Australia and New Zealand. PARTICIPANTS: One hundred twelve patients undergoing primary antireflux surgery were randomized to undergo either laparoscopic Nissen fundoplication (52 patients) or anterior 90 degrees partial fundoplication (60 patients). INTERVENTIONS: Laparoscopic Nissen fundoplication with division of the short gastric vessels or laparoscopic anterior 90 degrees partial fundoplication. MAIN OUTCOME MEASURES: Blinded assessment at 1 and 5 years' follow-up of clinical outcome for postoperative heartburn, dysphagia, gas-related symptoms, and satisfaction with the surgical outcome. Analog scales ranging from 0 to 10 were used to assess symptom severity. RESULTS: Ninety-seven patients underwent follow-up at 5 years. Three others died during follow-up, 4 refused follow-up, and 8 were lost to follow-up; 89% remained at 5-years' follow-up. At 5 years' follow-up, mean analog scores for heartburn were 2.2 for anterior fundoplication vs 0.9 for Nissen fundoplication (P=.003). There were no significant differences between the groups for dysphagia scores. The mean score for outcome satisfaction was 7.1 after anterior fundoplication vs 8.1 after Nissen fundoplication (P=.18). Eighty-eight percent reported a good or excellent outcome following Nissen fundoplication vs 77% following anterior fundoplication. CONCLUSIONS: Laparoscopic Nissen and anterior 90 degrees partial fundoplication achieve similar levels of patient satisfaction at 5 years' follow-up, with similar adverse effect profiles. However, at 5 years' follow-up, laparoscopic Nissen fundoplication achieves superior control of reflux symptoms. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Register Identifier: ACTRN12607000298415.

Laparoscopic versus open ventral hernia repair: a randomized controlled trial.

Laparoscopic and open techniques are both recognized treatment options for ventral hernias. We conducted a prospective randomized trial of both methods, to assess hernia recurrence, postoperative recovery and complications. Fifty-eight patients with ventral hernias were enrolled into the trial between August 2003 and December 2005. Of these, 31 underwent laparoscopic repair and 27 underwent open repair. Clinical parameters were documented on all patients during a median follow-up period of 27.5 months. The demographics of the two groups were similar. There was one recurrence in each of the laparoscopic and open groups. There was an equivalent rate of operative time, length of stay, postoperative pain scores, return to normal activities, wound infection and seroma formation between the two groups. Laparoscopic and open ventral hernia repair are comparable and offer low recurrence rates.

Long-term outcomes after laparoscopic bile duct exploration: a 5-year follow up of 150 consecutive patients.

BACKGROUND: The treatment of common bile duct stones discovered at routine intraoperative cholangiography includes postoperative endoscopic retrograde cholangiography or intraoperative laparoscopic common bile duct exploration. Given the equivalence of short-term outcome data for these two techniques, the choice of one over the other may be influenced by long-term follow-up data. We aimed to establish the long-term outcomes following laparoscopic common bile duct exploration and compare this with endoscopic retrograde cholangiography. METHODS: One hundred and fifty consecutive patients underwent laparoscopic common bile duct exploration between March 1998 and March 2006 carried out by a single surgeon. All were prospectively studied for 1 month followed by a late-term phone questionnaire ascertaining the prevalence of adverse symptoms. Patients presented with a standardized series of questions, with reports of symptoms corroborated by review of medical records. RESULTS: In 150 patients, operations included laparoscopic transcystic exploration (135), choledochotomy (10) and choledochoduodenostomy (2). At long-term follow up (mean 63 months), 116 (77.3%) patients were traceable, with 24 (20.7%) reporting an episode of pain and 18 (15.5%) had more than a single episode of pain. There was no long-term evidence of cholangitis, stricture or pancreatitis identified in any patient. CONCLUSION: Laparoscopic bile duct exploration appears not to increase the incidence of long-term adverse sequelae beyond the reported prevalence of postcholecystectomy symptoms. There was no incidence of bile duct stricture, cholangitis or pancreatitis. It is a safe procedure, which obviates the need and expense of preoperative or postoperative endoscopic retrograde cholangiography in most instances.

A review of natural orifice translumenal endoscopic surgery (NOTES) for intra-abdominal surgery: experimental models, techniques, and applicability to the clinical setting.

OBJECTIVE: Evaluation of models, techniques, outcomes, pitfalls, and applicability to the clinical setting of natural orifice translumenal endoscopic surgery (NOTES) for performing intra-abdominal surgery through a systematic review of the literature. SUMMARY BACKGROUND DATA: NOTES has attracted much recent attention for its potential to allow traditional surgical procedures to be performed entirely through a natural orifice. Amid the excitement for potentially scar-free surgery and abolishment of dermal incision-related complications, the safety and efficacy of this new surgical technology must be evaluated. METHODS: Studies were identified by searching MEDLINE, EMBASE, CINAHL, Current Contents, Cochrane Library, Entrez PubMed, Clinical Trials Database, National Health Services Centre for Reviews and Dissemination (NHS CRD) databases, and National Research Register from 2000 to June 2007. Studies identified in September 2007 were included if they were performed in live human subjects. RESULTS: Of the 34 studies included for review, 30 were experimental studies conducted in animals, thus the evidence base was very limited. Although intra-abdominal access could be achieved reliably via oral, anal, or urethral orifices, the optimal access route and method could not be established. Viscerotomy closure could not be achieved reliably in all cases and risk of peritoneal infection has not been adequately minimized. Although the majority of interventions could be performed in animals using NOTES, a number of technical problems were encountered that need to be resolved. CONCLUSIONS: NOTES is still in early stages of development and more robust technologies will be needed to achieve reliable closure and overcome technical challenges. Well-managed human studies need to be conducted to determine the safety and efficacy of NOTES in a clinical setting.

Quality of life following laparoscopic anterior 90 degrees versus Nissen fundoplication: results from a multicenter randomized trial.

BACKGROUND: The short-term clinical outcomes from a multicenter prospective randomized trial of laparoscopic Nissen versus anterior 90 degrees partial fundoplication have been reported previously. These demonstrated a high level of satisfaction with the overall outcome following anterior 90 degrees fundoplication. However, the results of postoperative objective tests and specific clinical symptoms are not always consistent with an individual patient's functional status and general well being following surgery, and quality of life (QOL) is also an important outcome to consider following surgery for reflux. Hence, QOL information was collected in this trial to investigate the hypothesis: improvements in QOL following laparoscopic antireflux surgery are greater after anterior 90 degrees partial fundoplication than after Nissen fundoplication. METHODS: Patients undergoing a laparoscopic fundoplication for gastro-esophageal reflux at one of nine university teaching hospitals in six major cities in Australia and New Zealand were randomized to undergo either laparoscopic Nissen or anterior 90 degrees partial fundoplication. Quality of life before and after surgery was assessed using validated questionnaires - the Short Form 36 general health questionnaire (SF36) and an Illness Behavior Questionnaire (IBQ). Patients were asked to complete these questionnaires preoperatively and at 3, 6, 12 and 24 months postoperatively. RESULTS: One hundred and twelve patients were randomized to undergo a Nissen fundoplication (52) or a 90 degrees anterior fundoplication (60). Patients who underwent anterior fundoplication reported significant improvements in eight of the nine SF36 scales compared to four of the nine following a Nissen fundoplication. The majority of these improvements occurred early in the postoperative period. With respect to the illness behavior data, there were no significant differences between the two procedures. Both groups had a significant improvement in disease conviction scores at all time points compared to their preoperative scores. CONCLUSIONS: Patients undergoing laparoscopic anterior 90 degrees partial fundoplication reported more QOL improvements in the early postoperative period than patients undergoing a Nissen fundoplication. However, the QOL outcome for both procedures was similar at later follow-up.

Postoperative ERCP versus laparoscopic choledochotomy for clearance of selected bile duct calculi: a randomized trial.

OBJECTIVE: Prospectively evaluate whether for patients having laparoscopic cholecystectomy with failed trans-cystic duct clearance of bile duct (BD) stones they should have laparoscopic choledochotomy or postoperative endoscopic retrograde cholangiography (ERCP). SUMMARY BACKGROUND DATA: Clinical management of BD stones found at laparoscopic cholecystectomy in the last decade has focused on pre-cholecystectomy detection with ERCP clearance in those with suspected stones. This clinical algorithm successfully clears the stones in most patients, but no stones are found in 20% to 60% of patients and rare unpredictably severe ERCP morbidity can result in this group. Our initial experience of 300 consecutive patients with fluoroscopic cholangiography and intraoperative clearance demonstrated that, for the pattern of stone disease we see, 66% of patients' BD stones can be cleared via the cystic duct with dramatic reduction in morbidity compared to the 33% requiring choledochotomy or ERCP. Given the limitations of the preoperative approach to BD stone clearance, this trial was designed to explore the limitations, for patients failing laparoscopic trans-cystic clearance, of laparoscopic choledochotomy or postoperative ERCP. METHODS: Across 7 metropolitan hospitals after failed trans-cystic duct clearance, patients were intraoperatively randomized to have either laparoscopic choledochotomy or postoperative ERCP. Exclusion criteria were: ERCP prior to referral for cholecystectomy, severe cholangitis or pancreatitis requiring immediate ERCP drainage, common BD diameter of less than 7 mm diameter, or if bilio-enteric drainage was required in addition to stone clearance. Drain decompression of the cleared BD was used in the presence of cholangitis, an edematous ampulla due to instrumentation or stone impaction and technical difficulties from local inflammation and fibrosis. The ERCP occurred prior to discharge from hospital. Mechanical and extracorporeal shockwave lithotripsy was available. Sphincter balloon dilation as an alternative to sphincterotomy to allow stone extraction was not used. Major endpoints for the trial were operative time, morbidity, retained stone rate, reoperation rate, and hospital stay. RESULTS: From June 1998 to February 2003, 372 patients with BD stones had successful trans-cystic duct clearance of stones in 286, leaving 86 patients randomized into the trial. Total operative time was 10.9 minutes longer in the choledochotomy group (158.8 minutes), with slightly shorter hospital stay 6.4 days versus 7.7 days. Bile leak occurred in 14.6% of those having choledochotomy with similar rates of pancreatitis (7.3% versus 8.8%), retained stones (2.4% versus 4.4%), reoperation (7.3% versus 6.6%), and overall morbidity (17% versus 13%). CONCLUSIONS: These data suggest that the majority of secondary BD stones can be diagnosed at the time of cholecystectomy and cleared trans-cystically, with those failing having either choledochotomy or postoperative ERCP. However, because of the small trial size, a significant chance exists that small differences in outcome may exist. We would avoid choledochotomy in ducts less than 7 mm measured at the time of operative cholangiogram and severely inflamed friable tissues leading to a difficult dissection. We would advocate choledochotomy as a good choice for patients after Billroth 11 gastrectomy, failed ERCP access, or where long delays would occur for patient transfer to other locations for the ERCP.

Multicenter, prospective, double-blind, randomized trial of laparoscopic nissen vs anterior 90 degrees partial fundoplication.

HYPOTHESIS: Laparoscopic anterior 90 degrees partial fundoplication for gastroesophageal reflux is associated with a lower incidence of postoperative dysphagia and other adverse effects compared with laparoscopic Nissen fundoplication. DESIGN: A multicenter, prospective, double-blind, randomized controlled trial. SETTING: Nine university teaching hospitals in 6 major cities in Australia and New Zealand. PARTICIPANTS: One hundred twelve patients with proven gastroesophageal reflux disease presenting for laparoscopic fundoplication were randomized to undergo either a Nissen (52 patients) or an anterior 90 degrees partial procedure (60 patients). Patients with esophageal motility disorders, patients requiring a concurrent abdominal procedure, and patients who had undergone previous antireflux surgery were excluded from this study. INTERVENTIONS: Laparoscopic Nissen fundoplication with division of the short gastric vessels or laparoscopic anterior 90 degrees partial fundoplication. MAIN OUTCOME MEASURES: Independent assessment of dysphagia, heartburn, and overall satisfaction 1, 3, and 6 months after surgery using multiple clinical grading systems. Objective measurement of esophageal manometric parameters, esophageal acid exposure, and endoscopic assessment. RESULTS: Postoperative dysphagia, and wind-related adverse effects were less common after a laparoscopic anterior 90 degrees partial fundoplication. Relief of heartburn was better following laparoscopic Nissen fundoplication. Overall satisfaction was better after anterior 90 degrees partial fundoplication. Lower esophageal sphincter pressure, acid exposure, and endoscopy findings were similar for both procedures. CONCLUSIONS: At the 6-month follow-up, laparoscopic anterior 90 degrees culine partial fundoplication is followed by fewer adverse effects than laparoscopic Nissen fundoplication with full fundal mobilization, and it achieves a higher rate of satisfaction with the overall outcome. However, this is offset to some extent by a greater likelihood of recurrent gastroesophageal reflux symptoms.