Laparoscopic ischemic conditioning of the stomach prior to esophagectomy induces gastric neo-angiogenesis.

BACKGROUND: The risk of an anastomotic leakage (AL) following Ivor-Lewis esophagectomy is increased in patients with calcifications of the aorta or a stenosis of the celiac trunc. Ischemic conditioning (ISCON) of the gastric conduit prior to esophagectomy is supposed to improve gastric vascularization at the anastomotic site. The prospective ISCON trial was conducted to proof the safety and feasibility of this strategy with partial gastric devascularization 14 days before esophagectomy in esophageal cancer patients with a compromised vascular status. This work reports the results from a translational project of the ISCON trial aimed to investigate variables of neo-angiogenesis. METHODS: Twenty esophageal cancer patients scheduled for esophagectomy were included in the ISCON trial. Serum samples (n = 11) were collected for measurement of biomarkers and biopsies (n = 12) of the gastric fundus were taken before and after ISCON of the gastric conduit. Serum samples were analyzed including 62 different cytokines. Vascularization of the gastric mucosa was assessed on paraffin-embedded sections stained against CD34 to detect the degree of microvascular density and vessel size. RESULTS: Between November 2019 and January 2022 patients were included in the ISCON Trial. While serum samples showed no differences regarding cytokine levels before and after ISCON biopsies of the gastric mucosa demonstrated a significant increase in microvascular density after ISCON as compared to the corresponding gastric sample before the intervention. CONCLUSION: The data prove that ISCON of the gastric conduit as esophageal substitute induces significant neo-angiogenesis in the gastric fundus which is considered as surrogate of an improved vascularization at the anastomotic site.

TEsoNet: knowledge transfer in surgical phase recognition from laparoscopic sleeve gastrectomy to the laparoscopic part of Ivor-Lewis esophagectomy.

BACKGROUND: Surgical phase recognition using computer vision presents an essential requirement for artificial intelligence-assisted analysis of surgical workflow. Its performance is heavily dependent on large amounts of annotated video data, which remain a limited resource, especially concerning highly specialized procedures. Knowledge transfer from common to more complex procedures can promote data efficiency. Phase recognition models trained on large, readily available datasets may be extrapolated and transferred to smaller datasets of different procedures to improve generalizability. The conditions under which transfer learning is appropriate and feasible remain to be established. METHODS: We defined ten operative phases for the laparoscopic part of Ivor-Lewis Esophagectomy through expert consensus. A dataset of 40 videos was annotated accordingly. The knowledge transfer capability of an established model architecture for phase recognition (CNN + LSTM) was adapted to generate a "Transferal Esophagectomy Network" (TEsoNet) for co-training and transfer learning from laparoscopic Sleeve Gastrectomy to the laparoscopic part of Ivor-Lewis Esophagectomy, exploring different training set compositions and training weights. RESULTS: The explored model architecture is capable of accurate phase detection in complex procedures, such as Esophagectomy, even with low quantities of training data. Knowledge transfer between two upper gastrointestinal procedures is feasible and achieves reasonable accuracy with respect to operative phases with high procedural overlap. CONCLUSION: Robust phase recognition models can achieve reasonable yet phase-specific accuracy through transfer learning and co-training between two related procedures, even when exposed to small amounts of training data of the target procedure. Further exploration is required to determine appropriate data amounts, key characteristics of the training procedure and temporal annotation methods required for successful transferal phase recognition. Transfer learning across different procedures addressing small datasets may increase data efficiency. Finally, to enable the surgical application of AI for intraoperative risk mitigation, coverage of rare, specialized procedures needs to be explored.

[Reconstruction and functional results after gastric resection]. / Rekonstruktionen und funktionelle Ergebnisse nach Magenresektion.

Depending on the extent of gastric resection, namely total, proximal or distal gastrectomy, different methods of reconstruction are available. These reconstructive procedures have not changed with the implementation of minimally invasive or robotic techniques in general but the spectrum of possible anastomotic techniques has been substantially expanded. Functional, in particular nutritional disorders with subsequent impairment of the health-related quality of life, are often diagnosed after gastric resections. The partial preservation of a gastric reservoir has a positive impact on the extent of these disorders. After total gastrectomy, the placement of a jejunal pouch significantly reduces the incidence of postoperative dumping symptoms. Following proximal gastrectomy, double-tract reconstruction offers certain functional advantages as compared to the simple Roux­Y reconstruction. In Germany, these reconstructive techniques are only used to a low extent and should be include in the repertoire of oncological gastric surgery with appropriate indications.

Primary laparoscopic fundoplication in selected patients with gastroesophageal reflux disease.

BACKGROUND: Despite proton pump inhibitors being a powerful therapeutic tool, laparoscopic fundoplication (LF) has proven successful in the treatment of gastroesophageal reflux disease (GERD), through mechanical augmentation of a weak antireflux barrier and the advantages of minimally invasive access. A critical patient selection for LF, based on thorough preoperative assessment, is important for the management of GERD-patients. The purpose of this study is to provide an overview on the management of GERD-patients treated by primary LF in a specialized center and to illustrate the possible outcome after several years. METHODS: Patients were selected after going through diagnostic workup consisting of patient's history and physical examination, upper gastrointestinal endoscopy, assessment of gastrointestinal Quality of Life Index, screening for somatoform disorders, functional assessment by esophageal manometry, (impedance)-24-hour-pH-monitoring, and selective radiographic studies. The indication for LF was based on EAES-guidelines. Either a floppy and short Nissen fundoplication was performed or a posterior Toupet-hemifundoplication was chosen. A long-term follow-up assessment was attempted after surgery. RESULTS: In total, n = 1131 patients were evaluated (603 males; 528 females; mean age; 48.3 years; and mean body mass index: 27). The mean duration between onset of symptoms and surgery was 8 years. Nissen: n = 873, Toupet: n = 258; conversion rateerativ: 0.5%; morbidity 4%, mortality: 1 (1131). Mean follow-up (n = 898; 79%): 5.6 years; pre/post-op results: esophagitis: 66%/12.1%; Gastrointestinal Quality of Life Index: median: 92/119; daily proton pump inhibitors-intake after surgery: 8%; and operative revisions 4.3%. CONCLUSIONS: In conclusion, our data show that careful patient selection for laparoscopic fundoplication and well-established technical concepts of mechanical sphincter augmentation can provide satisfying results in the majority of patients with severe GERD.

How effective is laparoscopic redo-antireflux surgery?

BACKGROUND: The failure-rate after primary antireflux surgery ranges from 3 to 30%. Reasons for failures are multifactorial. The aim of this study is to gain insight into the complex reasons for, and management of, failure after antireflux surgery. METHODS: Patients were selected for redo-surgery after a diagnostic workup consisting of history and physical examination, upper gastrointestinal endoscopy, quality-of-life assessment, screening for somatoform disorders, esophageal manometry, 24-hour-pH-impedance monitoring, and selective radiographic studies such as Barium-sandwich for esophageal passage and delayed gastric emptying. Perioperative and follow-up data were compiled between 2004 and 2017. RESULTS: In total, 578 datasets were analyzed. The patient cohort undergoing a first redo-procedure (n = 401) consisted of 36 patients after in-house primary LF and 365 external referrals (mean age: 62.1 years [25-87]; mean BMI 26 [20-34]). The majority of patients underwent a repeated total or partial laparoscopic fundoplication. Major reasons for failure were migration and insufficient mobilization during the primary operation. With each increasing number of required redo-operations, the complexity of the redo-procedure itself increased, follow-up quality-of-life decreased (GIQLI: 106; 101; and 100), and complication rate increased (intraoperative: 6,4-10%; postoperative: 4,5-19%/first to third redo). After three redo-operations, resections were frequently necessary (morbidity: 42%). CONCLUSIONS: Providing a careful patient selection, primary redo-antireflux procedures have proven to be highly successful. It is often the final chance for a satisfying result may be achieved upon performing a second redo-procedure. A third revision may solve critical problems, such as severe pain and/or inadequate nutritional intake. When resection is required, quality of life cannot be entirely normalized.

[Evidence in minimally invasive oncological surgery of the esophagus]. / Evidenz in der minimal-invasiven onkologischen Chirurgie des Ösophagus.

BACKGROUND: Thoracoabdominal esophagectomy still plays a major role in the oncological treatment for esophageal cancer. Minimally invasive procedures were developed to reduce the high rate of postoperative morbidity and mortality without negatively affecting the oncological outcome. OBJECTIVE: What evidence supports minimally invasive oncological surgery of the esophagus? Do patients benefit from minimally invasive esophagectomy compared to an open approach? Is the reduction of surgical access trauma specifically advantageous? MATERIAL AND METHODS: Review, evaluation and critical analysis of the international literature. RESULTS: A reduction in postoperative morbidity by decreasing surgical trauma was confirmed by three prospective randomized clinical trials, while showing at least similar oncological outcomes. Diverse retrospective analyses and meta-analyses also came to the same result. CONCLUSION: A minimization of surgical access trauma during thoracoabdominal esophagectomy reduces postoperative morbidity compared to conventional open surgery. Recent evidence suggests that oncological outcomes are not altered depending on the surgical approach.

[Neoadjuvant chemoradiotherapy or chemotherapy for locally advanced esophageal cancer?] / Neoadjuvante Radiochemotherapie oder Chemotherapie beim lokal fortgeschrittenen Ösophaguskarzinom?

BACKGROUND: According to international guidelines neoadjuvant chemoradiotherapy and chemotherapy are recommended for the treatment of locally advanced esophageal cancer. The treatment approach depends on the tumor entity (adenocarcinoma vs. squamous cell carcinoma). OBJECTIVE: What benefits do patients with locally advanced esophageal cancer have from neoadjuvant treatment? Is there information in the international literature on whether a particular neoadjuvant treatment is preferred? Does the type of neoadjuvant treatment depend on factors other than the tumor entity? Is there a standard in the drug composition of chemotherapy or a clearly defined chemoradiotherapy regimen? MATERIAL AND METHODS: A review, evaluation and critical analysis of the international literature were carried out. RESULTS: Patients with locally advanced esophageal cancer benefit from a neoadjuvant treatment. The current data situation for squamous cell carcinoma of the esophagus demonstrates a better response to neoadjuvant chemoradiotherapy compared to chemotherapy alone. Locally advanced adenocarcinoma of the esophagus can be treated with combined neoadjuvant chemoradiotherapy as well as by chemotherapy alone. Both lead to an improvement in the prognosis. There are often differences particularly among radiation treatment regimens in the different centers. Furthermore, the localization of the tumor can also be important for treatment decisions. CONCLUSION: A neoadjuvant treatment is clearly recommended for locally advanced esophageal cancer. Currently, chemoradiotherapy according to the CROSS protocol is preferred for squamous cell carcinoma. For adenocarcinoma both chemotherapy according to the FLOT protocol as well as chemoradiotherapy in a neoadjuvant treatment concept lead to an improvement in the prognosis.

Innovative fully robotic 4-arm Ivor Lewis esophagectomy for esophageal cancer (RAMIE4).

Nowadays robotic surgery is established for abdominal and thoracic surgery. It has been shown that complex procedures are feasible using robotic systems, e.g., da Vinci Xi, with a huge benefit in precision. Different techniques for esophageal cancer surgery are reported; however, only a few robotic and partial robotic procedures are described. Therefore, a fully robotic (abdominal and thoracic) Ivor Lewis esophageal resection using four robotic arms-RAMIE4-the standard technique used for lower esophageal cancer, is presented in this paper. The technique shown in the video was performed successfully in 100 cases in 24 months. The reconstruction is performed with a gastric conduit pull-up and intrathoracic manually inserted 28-mm circular end-to-side stapled anastomosis. This video demonstrates the feasibility of RAMIE4 in the abdomen and thorax and reveals advantages of the robotic assistance.

Robot-assisted minimally invasive esophagectomy (RAMIE) compared to conventional minimally invasive esophagectomy (MIE) for esophageal cancer: a propensity-matched analysis.

Robot-assisted minimally invasive esophagectomy (RAMIE) is increasingly being applied as treatment for esophageal cancer. In this study, the results of 50 RAMIE procedures were compared with 50 conventional minimally invasive esophagectomy (MIE) operations, which had been the standard treatment for esophageal cancer prior to the robotic era. Between April 2016 and March 2018, data of 100 consecutive patients with esophageal carcinoma undergoing modified Ivor Lewis esophagectomy were prospectively collected. All operations were performed by the same surgeon using an identical intrathoracic anastomotic reconstruction technique with the same perioperative management and pain control regimen. Intra-operative and postoperative complications were graded according to definitions stated by the Esophagectomy Complications Consensus Group. Data analysis was carried out with and without propensity score matching. Baseline characteristics did not show significant differences between the RAMIE and MIE group. Propensity score matching of the initial group of 100 patients resulted in two equal groups of 40 patients for each surgical approach. In the RAMIE group, the median total lymph node yield was 27 (range 13-84) compared to 23 in the MIE group (range 11-48), P = 0.053. Median intensive care unit (ICU) stay was 1 day (range 1-43) in the RAMIE group compared to 2 days (range 1-17) in the MIE group (P = 0.029). The incidence of postoperative complications was not significantly different between the two groups (P = 0.581). In this propensity-matched study comparing RAMIE to MIE, ICU stay was significantly shorter in the RAMIE group. There was a trend in improved lymphadenectomy in RAMIE.

[Surgical treatment of esophagotracheal and esophagobronchial fistulas]. / Chirurgische Versorgung ösophagotrachealer und -bronchialer Fisteln.

BACKGROUND: Esophagotracheal and esophagobronchial fistulas are pathological communications between the airway system and the digestive tract, which often lead to major pulmonary complications with a high mortality. Endoscopic treatment is the primary therapeutic approach; however, in cases of failure early surgical treatment is obligatory. METHODS: This article describes the clinical course of patients with esophagotracheal and esophagobronchial fistulas treated in this hospital over a period of 10 years. Patients were retrospectively analyzed with respect to the etiology of fistulas, management, in particular to the operative procedures, complications and outcome. RESULTS: Between 2009 and 2019, a total of 15 patients with esophagotracheal and esophagobronchial fistula were treated in this hospital. Of these 12 underwent an endoscopic intervention, of which 5 were successful. In total, eight patients needed surgical intervention, six of the eight surgically treated patients recovered fully, one had a recurrent fistula, which was successfully treated by subsequent endoscopy after surgery and one patient died. DISCUSSION: Management of esophagotracheal and esophagobronchial fistulas is challenging. This retrospective analysis reflects the published data with a success rate of endoscopic treatment in approximately 50%. Surgical intervention should be carried out after unsuccessful endoscopic treatment or if endoscopic treatment is primarily not feasible. Direct closure with resorbable sutures or reconstruction with alloplastic or allogeneic material should be preferred. For larger defects or high proximal esophagotracheal fistulas local transposition of muscular flaps or free muscular flaps play a major role. During operative closure of high intrathoracic or cervical fistulas, intraoperative neuromonitoring can be useful to prevent nerve damage.

[Lymphadenectomy in oncological visceral surgery-Part 2 : Cancer of the upper and lower intestinal tract]. / Lymphadenektomie in der onkologischen Viszeralchirurgie ­ Teil 2 : Karzinome des oberen und unteren Intestinaltraktes.

In cancers of the upper and lower intestinal tract the risk of lymphatic metastases depends on the histological results, tumor grading, and depth of tumor infiltration (T-stage). Pretherapeutic staging is of particular importance for determining the surgical strategy (local excision vs. en bloc resection with regional lymphadenectomy) as well as for evaluating the necessity of neoadjuvant therapy. While the first part on "Lymphadenectomy in oncological visceral surgery" focused on hepatobiliary and pancreatic cancer, this second part contains an overview of anatomical conditions of lymphatic drainage of the esophagus, stomach, duodenum, small intestine, colon, rectum and anus. Based on this, the principles and techniques of lymphadenectomy for cancer in these organs and the requirements on systematic regional lymphadenectomy in the actual TNM classification (8th edition) are discussed.

Preoperative endoscopic pyloric balloon dilatation decreases the rate of delayed gastric emptying after Ivor-Lewis esophagectomy.

Delayed gastric emptying (DGE) after Ivor-Lewis esophagectomy occurs postoperatively in up to 50% of the patients. This pyloric dysfunction can lead to severe secondary complications postoperatively such as early aspiration, pneumonia or may even have an impact on anastomotic healing and therefore leakage. Early detection of DGE is essential to prevent further complications. The common treatment postoperatively is endoscopic pyloric balloon dilatation (EPBD) after symptoms already occurred. In our work, we analyzed patients who received a preoperative EPBD during the routine restaging endoscopy and compared those patients to a control group to analyze if preoperative EPBD may prevent postoperative DGE and secondary additional complications. We performed a single-center retrospective analysis of 115 patients who received an Ivor-Lewis esophagectomy by the same surgeon between June 2015 and October 2017. Out of these 115 patients, 91 (79.1%) patients received EPBD preoperatively during the staging/restaging endoscopy (PDG, pyloric dilatation group). In 24 (20.9%) patients, preoperative EPBD was not performed due to stenotic esophageal tumors or logistic reasons (NDG, non-pyloric dilatation group). Data of the PDG and NDG group were compared regarding the rate of postoperative DGE as well as DGE and EPBD related complications. In total, 21 (18.3%) patients developed pyloric dysfunction requiring a total of 27 EPBD during follow-up. There were 12 (13.2%) patients in the PDG and 9 (37.5%) patients in the NDG (p = 0.014), respectively. DGE-related complications such as anastomotic leaks (p = 0.466), pulmonary complications (p = 0.466) and longer median hospital stay (p = 0.685) were more frequent in the NDG group; however this difference did not reach statistical significance. The success rate for postoperative EPBD with 20-mm balloons was lower (58.5%) compared to the usage of 30-mm balloons (93.3%). All pre- and postoperative EPBD were performed without any complications. Preoperative EPBD is feasible, safe and can be combined with restating endoscopy. It seems that preoperative EPBD reduces the incidence of DGE and can prevent the need for early postoperative endoscopic interventions. Our recommendation is therefore to perform an EPBD preoperatively when possible to reduce postoperative complications to a minimum. For postoperative EPBD, we recommend the use of the 30-mm balloon due to lower redilatation rates.

Change from Hybrid to Fully Minimally Invasive and Robotic Esophagectomy is Possible without Compromises.

BACKGROUND: The incidence of esophageal carcinoma is increasing in the western world, and esophageal resection is the essential therapy. Several studies report advantages of minimally invasive esophagectomies (MIEs) versus conventional open procedures (OPs). The benefits of the use of fully MIE or robot-assisted MIE (RAMIE) compared with the hybrid approaches (laparoscopic gastric preparation and open transthoracic esophagectomy) remain unclear. METHODS: Between July 2015 and August 2017, the data of 75 patients with esophageal carcinoma were prospectively registered. Of the 75 patients, 25 treated with a hybrid MIE (hybrid), 25 with total MIE (MIE), and 25 with RAMIE. All patients were operated by the same specialized surgeon in our center with an identical anastomotic technique (circular stapler). RESULTS: The overall 30- and 90-day mortality rates were 0 and 1.33% (1/75), respectively. Total hospital stay (p = 0.262), intensive care unit stay (p = 0.079), number of resected lymph nodes (p = 0.863), and R status (p = 0.132) did not differ statistically between the groups. However, pneumonia and wound infections occurred significantly and more frequently in the hybrid group compared with the minimally invasive groups (MIE and RAMIE) (p = 0.046 and p = 0.003, respectively). CONCLUSION: Comparable results regarding morbidity and short-term outcome could be achieved in the MIE and RAMIE groups compared with the hybrid group. The data indicate that the learning curve is low in surgeons changing the technique form hybrid esophagectomy to fully MIE. Additionally, the total minimally invasive approaches seem to be associated with a low incidence of complications such as pneumonia and wound infections.

Case Report: Seaweed Bezoar Masquerading as a Malignant Obstruction.

Bezoars represent a rare cause of small bowel obstruction (SBO). Nonoperative management of bezoars includes use of endoscopy with mechanical or chemical dissolution methods. When obstruction persists, surgical intervention becomes necessary. Here, we present the case of an Asian woman with a SBO secondary to a phytobezoar masquerading as a malignancy. She presented with two days of acute-on-chronic abdominal pain that started after eating seaweed. Initial computed tomography (CT) scan showed a SBO with a jejunal transition point and ill-defined liver lesions, worrisome for a malignant obstruction with liver metastases. Further imaging, however, showed the resolution of these artifacts. Subsequent laparotomy revealed a small bowel loop with copious obstructing seaweed. A distal stricture was palpated, and the involved segment was resected. Intraoperative liver ultrasound was negative, and final pathology revealed benign small intestine with a mild stricture. Given the rarity of bezoar-related obstructions, the diagnosis is often delayed particularly when confounding factors exist such as our patient's concomitant hepatic findings. Contrast-enhanced CT has a high sensitivity but a lower specificity in identifying bezoars. A high index of suspicion is therefore necessary especially when managing higher risk patients.

Foregut symptoms, somatoform tendencies, and the selection of patients for antireflux surgery.

A large variety of foregut symptoms can occur in patients with gastroesophageal reflux disease (GERD), which can overlap with other disorders such as somatoform disorders and dyspepsia. Due to unclear diagnostic situations, these patients are often not adequately treated. The aim of this study was the evaluation of patients with foregut symptoms, referred for possible antireflux surgery, regarding their relationship with GERD and somatization tendencies based on control data from an unselected population. Symptom evaluation and somatization screening were initiated both in volunteers and in patients with foregut symptoms and GERD. Unselected volunteers from a village population were also evaluated by symptom analysis and for somatisation tendency. In addition, patients with foregut symptoms were diagnosed for GERD, and symptom analysis and psychodiagnostic evaluation were performed. There is no major significant difference in the symptom-spectrum in patients with foregut symptoms, whether they have a proven pathologic acid exposure from GERD or not. The probability for the risk of somatization was 5.6% in the unselected population of nonpatient volunteers (n = 267). In patients with foregut symptoms (n = 750), the probability for the presence of somatoform tendencies was approximately 20%, independent whether these patients had a documented GERD or a normal esophageal acid exposure, implicating further diagnostic work-up for the selection of patients for antireflux surgery. There is a remarkable symptom load and variety in patients with GERD, in patients with foregut symptoms, and in an unselected population of volunteers. There is no difference in the risk for somatization between patients with foregut symptoms and those with documented GERD. Therapeutic decision making especially prior to antireflux surgery requires an awareness of mental and emotional challenges.

The potential and perspective of peroral endoscopic esophageal myotomy for achalasia.

The therapeutic spectrum of this disorder consists of medical therapy, endoscopic balloon dilatation, endoscopic Botox injection, open or laparoscopic cardia myotomy, and most recently transesophageal endoscopic myotomy (POEM peroral endoscopic myotomy). The most important requirement is a well-experienced team in interventional flexible endoscopy. The endoscopist as well as the assisting staff should have experience in advanced therapeutic endoscopic techniques and hemostasis to handle all necessary endoscopic instruments such as injection needles, needle knife, triangle knife, coagulation graspers, and endoscopic clip handling and closures. In addition, advanced surgical and especially laparoscopic skills and experience as well as surgical knowledge about esophageal disease must be available in case of conversion and/or consultation. Prior to this procedure, the patient undergoes a detailed diagnostic work-up to confirm the diagnosis of achalasia. The procedures are performed in general anesthesia. The patient is brought in a supine position, and the abdomen is free for inspection and palpation during the procedure. The myotomy can be performed in different locations around the esophageal circumference. In Europe, several centers with large experience in esophageal disease, laparoscopy, and especially advanced interventional endoscopy have started to introduce this POEM-technique in their clinical practice. Initial success and low complication rates are quite promising and show a great future perspective for this technique. In the USA, POEM is a procedure with a substantial increase in numbers performed in the past years with a low complication rate. The largest series are performed in Asia with a great clinical success. The perspective of POEM may be the lesser access trauma. Its potential can be also realized in Redo cases, where experienced centers have initial experience with POEM after POEM and POEM after LHMD.

[Justification for the mandibular-maxillary order in bimaxillary osteotomy]. / Justification de l'ordre mandibule-maxillaire dans l'ostéotomie maxillomandibulaire.

INTRODUCTION: Our aim was to study the reliability of sagittal split osteotomy and Le Fort I osteotomy respectively, and to try to judge objectively the impact of their order for the final result of bimaxillary osteotomy. PATIENTS AND METHOD: Fifty patients were included. For each we calculated the errors generated by sagittal split osteotomies on one hand and Le Fort I osteotomy on the other hand, by performing a peroperative splint after each osteotomy. RESULTS: After sagittal split osteotomies changes in the anteroposterior direction were present in 74% of cases with an average amplitude of 0.32mm. They were less frequent in the transversal direction, 54% of cases, with a smaller amplitude (0.19mm). After Le Fort I osteotomy, there was no difference in 92% of cases with an average error of 0.02mm in the anteroposterior direction. No errors were observed in the transverse direction. DISCUSSION AND CONCLUSION: Le Fort I positioning is remarkably accurate contrary to the sagittal split. Using Le Fort I osteotomy first and mandibular sagittal split second has for drawback to perpetuate the errors of the sagittal split. The reverse order, beginning with the mandible, allows correction of sagittal split mistakes with the Le Fort I osteotomy. So it seems that the latter order is more logical and preferable.

[Intermaxillary fixation: technique and benefit for piezosurgical sagittal split osteotomy]. / Blocage maxillomandibulaire: technique et intérêt dans le clivage sagittal piézoélectrique.

INTRODUCTION: The aim of this study was to assess piezosurgical sagittal split osteotomy with peroperative inter maxillary fixation. MATERIAL AND METHOD: We studied 25 bimaxillary osteotomies, 50 sagittal split osteotomies performed with this technique. It included both maxillomandibular fixation during all the split osteotomy and performing split osteotomy in five steps. For each case, we noted the type of dysmorphia, the size of split osteotomy and the time required for surgery, along with common data such as sex, age, etc. The data was compared to results of a previous series of patients also operated with Piezosurgery but without peroperative maxillomandibular fixation. RESULTS: Using peroperative maxillomandibular fixation during piezosurgical bilateral sagittal osteotomy decreases the length of surgery by 33%, allows 9 times out of 10 for complete splitting, including the basilar edge, has no adverse effect especially on orthodontic material. DISCUSSION: Piezosurgery is a great progress for orthognatic surgery because of its precision and ability to preserve soft tissues. But it requires modification of the usual technique for mechanical section. Using peroperative inter maxillary fixation during ultrasonic splitting is a remarkably effective and easy technical modification.

Preparation and characterization TiO(x)-Pt/C catalyst for hydrogen oxidation reaction.

The hydrogen oxidation reaction (HOR) was studied at the home made TiO(x)-Pt/C nanocatalysts in 0.5 mol dm(-3) HClO(4) at 25 degrees C. Pt/C catalyst was first synthesized by modified ethylene glycol method (EG) on commercially used carbon support (Vulcan XC-72). Then TiO(x)-Pt/C catalyst was prepared by the polyole method followed by TiO(x) post-deposition. The synthesized catalyst was characterized by XRD, TEM and EDX techniques. It was found that Pt/C catalyst nanoparticles were homogenously distributed over carbon support with the mean particle size of about 2.4 nm. The quite similar, homogenous distribution and particle size were obtained for Pt/C doped by TiO(x) catalyst which was the confirmation that TiO(x) post-deposition did not lead to significant growth of the Pt nanoparticles. The electrochemically active surface area of the catalyst was determined by using the cyclic voltammetry technique.The kinetics of hydrogen oxidation was investigated by the linear sweep voltammetry technique at the rotating disc electrode (RDE). The kinetic equations used for the analysis were derived considering the reversible or irreversible nature of the kinetics of the HOR. It was found that the hydrogen oxidation reaction for an investigated catalyst proceeded as an electrochemically reversible reaction. The values determined for the kinetic parameters-Tafel slope of 28 mV dec(-1) and exchange current density about 0.4 mA cm(-2)(Pt) are in good agreement with usually reported values for a hydrogen oxidation reaction with platinum catalysts in acid solutions.

[Preliminary results of applying the inverse stapedotomy].

The authors have analyzed a group of 90 patients (105 operations) that have underwent stapes surgery over three years period. First group of 40 patients (45 operations) have been operated on by a classic stapedotomy from 2006 to 2007 and the second group of 50 patients (60 operations) by inverse stapedotomy in 2007. Manual perforator has been used in all of the patients. In a group of patients operated by inverse technique not a single case of floating basal plate has occurred during surgery. Rate of postoperative complaints regarding nausea and balance disorders was considerably lower when reversal of the steps has been used. Closure of air bone gap better than 20dB in about 80% patients in both series, with slight advantage of the inverse technique, but no statistically significant difference was proven. Inverse stapedotomy is efficient procedure as compared to classic stapedotomy with less intraoperative complications and postoperative complaints. Postoperative audiograms have shown similar improvement of hearing thresholds in both groups.