[Retrieval of a migrated plastic stent in a 51-year-old man]. / Bergung eines migrierten Doppel-Pigtail-Stents bei einem 51-jährigen Patienten.

BACKGROUND: Endosonographically guided transgastric drainage is the first-line interventional therapy of walled-off necrosis and symptomatic pancreatic pseudocysts in necrotizing pancreatitis. Plastic stents or lumen apposing metal stents are commonly used. A possible complication of endoscopic therapy is stent migration. CASE REPORT: We report upon a 51-year-old man who presented with acute necrotizing pancreatitis. Transgastric necrosectomy was performed and 5 transmural double-pigtail stents (DPS) were left in situ to drain the residual retroperitoneal cavity. The patient recovered and 4 stents were endoscopically removed 5 weeks later on an outpatient basis, whereas the fifth stent was suspected to have passed spontaneously via the natural route. The asymptomatic patient presented 3 months later for follow-up computed tomography. The necrosis had healed but one DPS was seen beyond the gastric wall near the kidney. Transmural access to the stent could be achieved by an endosonographically guided puncture toward the proximal portion of the stent followed by placement of a hydrophilic guidewire alongside the stent. A new gastrostomy was created by using a 6F cystotome followed by wire-guided dilation with a 12 mm balloon. The stent could then be grasped with transmurally inserted rat-tooth forceps and repositioned across the gastrostomy site. The patient was given prophylactic antibiotics. After removal of the stent, the patient could be discharged. CONCLUSION: Herein, we present the successful endosonographically guided transmural removal of a retroperitoneally migrated plastic stent. Of note, in our patient we had to rely completely on endosonography and radiography for localization and targeting of the stent, since the former necrotic cavity had meanwhile completely healed.

EndoResect study: endoscopic full-thickness resection of gastric subepithelial tumors.

BACKGROUND AND STUDY AIMS: Endoscopic resection of gastric subepithelial tumors (SETs) carries a high risk of perforation. New techniques such as use of the over-the-scope clip (OTSC) may enable secure endoscopic closure of perforations. We aimed to evaluate the feasibility of endoscopic resection of small gastric SETs using a grasp-and-snare technique followed by OTSC closure of the gastric wall if necessary. PATIENTS AND METHODS: In this prospective study 20 consecutive patients who presented with gastric SETs ≤ 3 cm were enrolled. Endoscopic resection was performed using a double-channel endoscope, a tissue anchor and a monofilament snare. If perforation occurred, the aim was to achieve complete closure with a tissue twin grasper and the OTSC. Procedures were performed under laparoscopic control using a 5-mm optic, which was introduced via a single 5-mm trocar through the umbilicus. All patients were followed up for 3 months after the procedure. RESULTS: In 6 /20 patients a pure endoscopic approach was impossible and a switch to laparoscopic wedge resection was necessary (large tumor size in 2 /6 patients; mainly extraluminal growth in 4 /6 patients). Solely endoscopic resection was successfully performed in the remaining 14 patients. Amongst these, laparoscopic control was impossible in two cases. Perforation occurred in 6 /14 patients but gastric closure with the OTSC was performed successfully in all these cases. No complications occurred and follow-up was unremarkable. CONCLUSION: Endoscopic snare resection enables safe treatment of small gastric SETs (diameter ≤ 3 cm) and seems faster and easier to perform than other endoscopic resection techniques, such as endoscopic submucosal dissection (ESD) or submucosal tunneling. Perforations occurring after full-thickness resection can be adequately managed by OTSC closure. Solely endoscopic resection without laparoscopic control seems possible in selected patients with tumors known to have purely intraluminal growth.

Argon plasma coagulation of gastric inlet patches for the treatment of globus sensation: it is an effective therapy in the long term.

AIM: To determine the long-term effect of argon plasma coagulation (APC) of gastric inlet patches in the cervical esophagus for patients suffering from globus sensation. METHODS: We intended to follow up all patients between 2004 and 2011 (n = 49) who received argon plasma ablation of gastric inlet patches for globus sensation at our clinic. Symptoms were assessed by a visual analogue scale (VAS) in 31 of 49 patients. Follow-up endoscopy of the upper gastrointestinal tract was performed to confirm residual or relapsed cervical inlet patches. RESULTS: After a median period of 27 months, APC was assessed as a successful therapy in 23 of 31 patients (74%). VAS scores decreased significantly from 7.6 to 4.0 in the long term. Twenty-two of 31 patients were willing to undergo follow-up endoscopy. Endoscopy revealed recurrent/residual gastric inlet patches after APC in 11 of 22 cases. These patients suffered from a significant relapse of symptoms in the postinterventional period (p < 0.001). CONCLUSION: This retrospective study indicates that APC of gastric inlet patches for the treatment of globus sensation might be a sufficient therapy option. Recurrences or residual heterotopic gastric mucosa are possible and seem to be associated with a relapse of symptoms. Therefore, endoscopic follow-up and retreatment might be necessary if globus sensation is not sufficiently eliminated.

[CMV-associated enterocolitis due to primary CMV infection in the immunocompetent]. / CMV-assoziierte Enterokolitis im Rahmen einer primären CMV-Infektion im Immunkompetenten.

Cytomegalovirus (CMV) plays an important role in non-immunocompetent patients due to its high seroprevalence and life-long persistence. However, cases of severe CMV infections are also described in the immunocompetent. Here in particular, the gastrointestinal involvement is of major importance. We describe the case of a 29-year-old immunocompetent young man, who presented with a primary CMV infection mainly of the colon with clinical signs of bloody diarrhoea, fever, hepatitis and haemolysis. The diagnosis was established on the basis of a suspicious endoscopic finding with immunohistochemical detection of CMV in the colonic mucosa, a positive CMV viral load in the peripheral blood and an immune system response typical for primary infection. Based on this case and previous publications, we suggest that a colonoscopy and diagnostic procedures for CMV should be considered if the patient presents with gastrointestinal symptoms like (bloody) diarrhoea, fever, and hepatitis. In a severe case, we recommend antiviral therapy due to a high mortality that has been reported for CMV colitis in immunocompetent individuals.

Bispectral index monitoring of midazolam and propofol sedation during endoscopic retrograde cholangiopancreatography: a randomized clinical trial (the EndoBIS study).

INTRODUCTION: Bispectral index (BIS) monitoring provides a non-invasive measure of the level of sedation. The purpose of this randomized, single-blind clinical trial was to evaluate whether BIS monitoring of sedation would lead to improved oxygenation and a reduced rate of cardiopulmonary complications during endoscopy. PATIENTS AND METHODS: Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) under procedural sedation with a combination of low dose midazolam and propofol were randomly assigned to either standard monitoring of sedation only (BIS-blinded arm) or an open arm in which additional BIS monitoring was available (BIS-open arm). In the BIS-open arm, propofol administration was to be withheld if BIS values were <55. The primary study end point was the mean oxygen saturation per patient. Secondary end points were the rates of cardiopulmonary complications, propofol dose, quality of sedation (patient cooperation as rated by the endoscopist and patient satisfaction), and recovery. RESULTS: A total of 144 patients were enrolled and included in the intention-to-treat analysis. Mean oxygen saturation per patient was 97.7% in the BIS-open arm and 97.6% in the BIS-blinded arm (P=0.71). Total rates of cardiopulmonary complications, single numbers of hypoxemic, bradycardic, and hypotensive events, mean propofol doses, and quality of sedation also showed no statistically significant differences between the groups. However, BIS monitoring did result in faster recovery of patients as reflected by shorter times to eye opening (P=0.001), first verbal response (P=0.02), and leaving the procedure room (P<0.001). CONCLUSIONS: The use of additional BIS monitoring did not lead to improved oxygenation or a reduced rate of cardiopulmonary complications. Recovery times after the procedure were shorter than with standard monitoring alone, but the clinical benefit for daily practice may be limited.

Hemodynamics after endoscopic submucosal injection of epinephrine in a porcine model.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal injection of epinephrine may cause systemic effects on the cardiovascular system. The aim of this experimental study was to assess systemic hemodynamic changes after submucosal injection of epinephrine during upper gastrointestinal endoscopy in a porcine model. METHODS: Measurements were taken from 12 pigs under general anesthesia. During gastroscopy 5 mL of normal saline, and 2.5 mL and 5 mL of epinephrine (1:10,000) were injected into the submucosal layers of the gastric antrum, corpus, and distal esophagus. After each injection, the cardiac index and global end diastolic volume index (GEDVI, reflecting preload) were measured every 3 minutes by transpulmonary thermodilution for a minimum of 12 minutes. The following parameters were also recorded: heart rate, mean arterial pressure (MAP), and systemic vascular resistance index (SVRI, reflecting afterload). RESULTS: Significant hemodynamic changes were observed after submucosal injection of epinephrine into the esophagus, including heart rate (maximum + 4 %) and MAP (maximum - 4%) after injection of 2.5 mL epinephrine, and stronger changes in heart rate (maximum +13%), cardiac index (maximum +21%), MAP (maximum -4%), and SVRI (maximum -12%) after the injection of 5 mL epinephrine. After submucosal injection of epinephrine into the gastric antrum and corpus, hemodynamic effects were less evident. Here significant changes were observed in heart rate (maximum +3%), MAP (maximum -2%), cardiac index (maximum +7%), and SVRI (maximum -8%) only after the injection of 5 mL epinephrine into the antrum. CONCLUSION: Endoscopic submucosal injection of epinephrine is associated with changes in systemic hemodynamic parameters, especially when performed in the esophagus, and the procedure might therefore induce harmful side effects.

[Endoscopic and percutaneous intervention in the long-term treatment of benign biliary stenosis. A 71-year-old patient with cholestasis following radiotherapy]. / Endoskopische und perkutane Interventionen in der Langzeitbehandlung benigner Gallengangstenosen : 71-jähriger Patient mit Cholestase nach Radiatio.

Benign biliary stenosis can have various causes and requires differentiation from disorders caused by malignant disease. Treatment of benign stenosis is often difficult and includes treatment modalities such as endoscopic, percutaneous or surgical interventions. Exact knowledge of the etiology and localization of the stenosis is essential when selecting the appropriate method of treatment. Here we present the case of a 71-year-old patient admitted to our hospital with cholangitis 13 years after undergoing radiotherapy of the renal bed due to hypernephroma of the right kidney. The patient was diagnosed with common bile duct stenosis due to the secondary effects of radiation, which is rarely reported in the literature. Our case covers a total treatment period of 15 years, enabling us to also discuss a viable sequence of treatment modalities in the treatment of benign bile duct stenosis.

Fluorescein-enhanced autofluorescence imaging for accurate differentiation of neoplastic from non-neoplastic colorectal polyps: a feasibility study.

BACKGROUND: Autofluorescence imaging (AFI) is sensitive but not specific for differentiating neoplastic from non-neoplastic colorectal polyps. We aimed to determine the sensitivity and specificity of fluorescein-enhanced AFI (FAFI) in differentiating neoplastic from non-neoplastic colorectal polyps. METHODS: All patients with colorectal polyps detected during AFI colonoscopy received intravenous fluorescein followed by AFI (FAFI). The video sequences were recorded and divided into a learning group and a test group. AFI and FAFI criteria for neoplastic and non-neoplastic lesions were determined after viewing videos in the learning group unblinded to histology. Videos in the test group were viewed blinded to histology, and diagnoses of neoplastic versus non-neoplastic were made for AFI and FAFI using the predetermined criteria. Still frames were objectively measured for red:green ratio (AFI) and green contrast (FAFI). RESULTS: Eight videos (four neoplastic, four non-neoplastic) were used for the learning group. Criteria for neoplasia when using FAFI were determined as the presence of a patchy or granular pattern which appeared more fluorescent green compared with the background. For AFI, purple or pink represented neoplasia; green represented non-neoplasia. In the test group (13 neoplastic, 12 non-neoplastic), for differentiating between neoplasia and non-neoplasia, subjective analysis of video sequences yielded a sensitivity of 100 % for AFI and 100 % for FAFI ( P = 1.000), and a specificity of 16.7 % for AFI and 91.7 % for FAFI ( P = 0.004). Using objective color analysis, the area under the receiver operating characteristics curve was 0.647 for AFI using the red:green ratio to distinguish between neoplasia and non-neoplasia, and 0.994 for FAFI using green contrast. CONCLUSIONS: FAFI accurately differentiated between neoplastic and non-neoplastic colorectal polyps.

Natural-orifice transluminal endoscopic surgery: low-pressure pneumoperitoneum is sufficient and is associated with an improved cardiopulmonary response (PressurePig Study).

BACKGROUND AND AIMS: The aim of this randomized trial in the acute porcine model was to compare the quality of transgastric peritoneoscopy with the use of low-pressure versus standard-pressure pneumoperitoneum and to evaluate the respective associated cardiopulmonary changes. METHODS: For transgastric peritoneoscopy, carbon dioxide was insufflated via the endoscope for a constant intraperitoneal pressure of 6 mmHg or 12 mmHg in 9 pigs each. The quality of transgastric peritoneoscopy was rated on a visual analog scale (0 mm, min.; 100 mm, max.) by the endoscopist, who was blinded to the intraperitoneal pressure. The cardiac index and global end-diastolic volume index (GEDVI, reflecting preload) were measured every 3 minutes by transpulmonary thermodilution. The following were also recorded: heart rate, mean arterial pressure (MAP), systemic vascular resistance index (SVRI, reflecting afterload), peak inspiratory pressure (PIP), pH, PCO (2), and PO (2). RESULTS: The quality of transgastric peritoneoscopy with the use of low-pressure pneumoperitoneum was not inferior to that obtained using standard-pressure pneumoperitoneum (87.0 mm vs. 87.3 mm; P<0.05). In both groups we observed a statistically significant rise in MAP and SVRI. The increase in SVRI was less pronounced during low-pressure peritoneum ( P=0.042), indicating a reduced stress response in comparison to standard-pressure peritoneum. There were no relevant differences between the groups in relation to cardiac index, GEDVI, and heart rate. An intra-abdominal pressure of 6 mmHg also led to better oxygenation ( P=0.031 for difference in PO (2) between the two groups) due to lower peak inspiratory pressure ( P<0.001 for difference). There were only slight differences between the groups with regard to pH and PCO (2). CONCLUSIONS: Pneumoperitoneum of 12-16 mmHg is used for standard laparoscopy. For NOTES, low-pressure pneumoperitoneum is sufficient and is associated with an improved cardiopulmonary response compared to standard-pressure pneumoperitoneum.

NOTES for the cardia: antireflux therapy via transluminal access.

BACKGROUND AND STUDY AIMS: The current standard for surgical antireflux therapy is laparoscopic Nissen fundoplication, but natural orifice transluminal endoscopic surgery (NOTES) enables even less invasive access to the peritoneal cavity. We therefore aimed to evaluate a NOTES approach to antireflux therapy. PATIENTS AND METHODS: An animal study including 24 pigs (16 nonsurvival and eight survival). After the peritoneal cavity had been accessed via the rectosigmoid, the gastroesophageal junction (GEJ) was laid open using conventional endoscopic instruments. Thereafter, a transcutaneously introduced hook was used for tunneling and lifting of the distal esophagus. Finally, an antireflux ring was placed around the cardia. Animals were observed over 10 days in the survival series. Correct application of the prosthesis, adverse events as a result of the procedure, and bacterial contamination were evaluated by autopsy. RESULTS: The esophagogastric junction was strengthened by applying the ring prosthesis in 22 of 24 animals. Four bleeding episodes were observed, three of which were handled endoscopically. Correct placement of the prosthesis was accomplished in 21 of 22 animals. In the survival series, 1 pig died after transhiatal herniation of the stomach, and 1 pig suffered from peritonitis due to intraoperative contamination. In 7 of the 8 survival animals, no bacterial growth was noted by smear culture. The intervention had to be performed as a hybrid NOTES procedure in all cases. CONCLUSION: Exposure of the GEJ and placement of an antireflux prosthesis via a hybrid NOTES procedure is feasible, despite some complications. This approach may be considered as a basis for optimization and further development of pure NOTES antireflux procedures.

Natural orifice transluminal endoscopic surgery: cardiopulmonary safety of transesophageal mediastinoscopy.

BACKGROUND AND STUDY AIMS: Physiological reactions during natural orifice transluminal endoscopic surgery (NOTES) mediastinoscopy may lead to cardiorespiratory depression. The aim of the current study was to assess cardiopulmonary changes during transesophageal mediastinoscopy in an acute porcine model. METHODS: Transesophageal mediastinoscopy was performed under general anesthesia in eight female pigs with a bodyweight of 39 +/- 6 kg. Mediastinal access was achieved via a submucosal tunnel. The cardiac index and global end-diastolic volume index (reflecting preload) were measured every 3 minutes by transpulmonary thermodilution. The following parameters were also recorded: mediastinal pressure, heart rate, mean arterial pressure, systemic vascular resistance index (SVRI; reflecting afterload), peak inspiratory pressure, pH, pCO (2), and pO (2). RESULTS: In three animals, small tears in the parietal pleura resulted in tension pneumothoraces. The associated cardioplumonary deterioration was fatal in one pig. The other two pigs recovered after decompression with a chest tube. In the remaining five animals there were only mild hemodynamic and respiratory changes during mediastinoscopy. There was a significant ( P = 0.005) but minor transient fall in cardiac index, which correlated with a small rise in SVRI (r = - 0.857, P < 0.001). In the pigs with uncomplicated mediastinoscopy, on-demand insufflation via the endoscope resulted in median mediastinal pressures of 4.5 mm Hg (range 2.3 - 10.2 mm Hg). Overall, mediastinal and thoracic structures could be identified without difficulty via the transesophageal approach. CONCLUSIONS: NOTES mediastinoscopy carries a substantial risk of inadvertent development of a pneumothorax. Otherwise, it leads to negligible hemodynamic and pulmonary changes. In conclusion, close monitoring for the presence of a pneumothorax during NOTES mediastinoscopy appears to be mandatory.

The "ELITE" model: construct validation of a new training system for natural orifice transluminal endoscopic surgery (NOTES).

BACKGROUND AND STUDY AIMS: The ELITE (endoscopic-laparoscopic interdisciplinary training entity) trainer is a new ex vivo model designed to train conventional laparoscopic and endoscopic skills and to perform hybrid interventions. The aim of the present study was to assess its usefulness for natural orifice transluminal endoscopic surgery (NOTES) procedures. MATERIALS AND METHODS: A group of 30 participants (eight gastroenterologists, 22 surgeons) ranging from novices to experts completed the following tasks. Via a trans-sigmoidal approach, anchor points in each quadrant in the abdominal cavity had to be reached. Each participant performed five consecutive courses. The time needed to perform the experiment was evaluated. In a second step to assess advanced skill for NOTES in an external face validation, 20 randomly selected individuals performed a cholecystectomy via the same trans-sigmoidal access. RESULTS: All participants passed a significant learning curve during the assessment (total time needed: 473.1 +/- 178.5 seconds for first pass vs. 321.9 +/- 182.0 seconds for fifth pass; P = 0.02, Wilcoxon test). There were 15 novices and 15 endoscopy experts. Significant differences were observed for the total time required to perform the respective procedures between these two groups (first pass: 394.3 +/- 176.6 seconds for experts vs. 531.9 +/- 166.7 seconds for novices; P = 0.040, Mann-Whitney test). Furthermore, NOTES cholecystectomies could successfully be simulated. Participants considered the ELITE to represent a useful simulator for NOTES. CONCLUSION: The newly developed ELITE trainer is a suitable tool to train NOTES techniques. Experts could reliably be distinguished from novices and a significant progress by training could be demonstrated.

[Natural orifices transluminal endoscopic surgery (NOTES) in Germany: summary of the working group reports of the "D-NOTES meeting 2009"]. / Endoskopisches Operieren über natürliche Körperöffnungen (NOTES) in Deutschland: Zusammenfassung der Arbeitsgruppensitzungen der "D-NOTES 2009"

The D-NOTES-group met in June 2009 for an evaluation of ongoing preclinical and clinical activities in natural orifice endoscopic surgery and the further coordination of research in Germany. Different working groups with various topics were formed. Consensus statements among various participants with different scientific and medical background were initiated. In summary, important topics were handled such as the correct handling of bacterial contamination and related complications, the question of the ideal entry point and a secure closure, interdisciplinary cooperation, and matters related to training and education. Furthermore, participants agreed on terminological basics. A to-do-list for medical engineering was formulated.

A novel and practicable ERCP training system with simulated fluoroscopy.

INTRODUCTION: Simulators facilitate the acquisition of technical skills for endoscopy. Here, we describe the development, introduction, and first evaluation of a novel generation of mechanical endoscopic retrograde cholangiopancreatography (ERCP) simulation models with simulated fluoroscopy, the X-Vision ERCP Training System. METHODS: A custom-made modular ERCP simulation system was built with the use of universally obtainable materials and tools. The trainee controls ERCP activities on two screens: the aspect of the papilla and duodenum is shown on the conventional endoscopy monitor, and the trainee's actions in the equivalents of the pancreaticobiliary ducts are shown on the viewing screen of the model. Thereby, the latter screen serves as a substitute for fluoroscopy. Currently, four different models are available, allowing simulation of selective cannulation of the pancreatic or bile duct, intubation of differently arranged papillae, stent placement, and sphincterotomy of a biopapilla. The X-Vision ERCP Training System was first used during an ERCP course attended by 26 endoscopists. Trainees were supervised by an ERCP expert and an experienced ERCP nurse at each training model. The training system was evaluated by the participants and experts using a specific questionnaire. RESULTS: During the course there were no technical problems related to the X-Vision ERCP Training System. After sphincterotomy the organic papillae could easily be exchanged within less than 15 seconds. Overall, the X-Vision ERCP Training System achieved favorable results in all categories assessed. CONCLUSION: The new X-Vision ERCP Training System is simple and effective. A first evaluation in the context of an ERCP course showed impressive results.

Colonoscopy and polypectomy with a side-viewing endoscope.

BACKGROUND AND STUDY AIMS: Some colorectal polyps cannot be adequately viewed using forward-viewing colonoscopes because of their location behind mucosal folds or bends in the bowel. We performed polypectomy using side-viewing duodenoscopes for these problematic polyps in order to avoid incomplete polypectomy or the need for surgical intervention. PATIENTS AND METHODS: Between April 2000 and August 2003, polypectomy with a side-viewing endoscope was intended in 15 patients (seven men, eight women; mean age 63.7 years, median age 59 years, range 38-88 years) at our institution. In all these patients, polypectomy had been attempted previously with a forward-viewing colonoscope by at least one experienced endoscopist without success. The duodenoscope was advanced with slight bending of the tip to achieve a sloped forward view. RESULTS: Colorectal polyps were macroscopically completely removed in 11/15 patients. One polyp near the ileocecal valve could only be partially removed with the side-viewing endoscope; and one large flat rectal adenoma, one recurrent rectal polyp (after a previous incomplete conventional polypectomy), and one polyp near the ileocecal valve could not be removed. We observed no procedure-related complications. Endoscopic follow-up was possible in seven of the 11 patients in whom the polyps were successfully resected, with no evidence of recurrence (mean follow-up 27 months). CONCLUSIONS: Polypectomy with the side-viewing duodenoscope is a safe and effective method. It is a therapeutic option when polyps are not adequately accessible using a conventional approach.

Transgastric in vivo histology in the peritoneal cavity using miniprobe-based confocal fluorescence microscopy in an acute porcine model.

BACKGROUND AND STUDY AIMS: Natural orifice transluminal endoscopic surgery (NOTES) is an emerging technology. Apart from its therapeutic implications, this type of access to the peritoneal cavity might also be useful for targeted in vivo histological investigation by means of confocal fluorescence microscopy. In this study we therefore aimed to assess the feasibility of miniprobe-based confocal fluorescence microscopy during transgastric endoscopy in an acute porcine model. MATERIALS AND METHODS: Transgastric in vivo histology was performed in five pigs, under general anesthesia. After incision of the anterior gastric wall, a double-channel video gastroscope was advanced into the peritoneal cavity. A flexible confocal miniprobe was introduced through the instrument channel of the endoscope after intravenous injection of 10 mL of fluorescein 1% in four of the pigs and of 50 mL of fluorescein isothiocyanate-dextran 150 000 4% in the fifth pig. The tip of the miniprobe was then placed on the peritoneal layer, the liver, and the spleen for confocal laser microscopy. RESULTS: Probes were easily attached to the peritoneal layer, the liver, and the spleen under direct visualization with the endoscope. Dynamic microscopic images of these organs were obtained with a frame rate of 12 frames per second. The flow of erythrocytes through blood vessels could be seen. The microstructural components of organs, such as lobules of the liver, were also easily identified. CONCLUSIONS: In vivo histology in the peritoneal cavity is feasible during NOTES and this technique combines the minimally invasive approach to the intraperitoneal organs afforded by NOTES and real-time, in vivo acquisition of dynamic histological images.

Changes in intra-abdominal pressure, hemodynamics, and peak inspiratory pressure during gastroscopy in a porcine model.

BACKGROUND AND STUDY AIMS: The aim of this experimental study was to assess the effect of gastric insufflation on intra-abdominal pressure (IAP) and associated hemodynamic and respiratory changes during upper gastrointestinal endoscopy. METHODS: Measurements were taken from pigs under general anesthesia with controlled ventilation. Gastroscopy was carried out with continuous insufflation of air by a standard endoscopic light source/insufflator. The cardiac index and global end-diastolic volume index (GEDVI; reflecting preload) were measured by transpulmonary thermodilution. IAP, heart rate, mean arterial pressure (MAP), central venous pressure, systemic vascular resistance index (SVRI; reflecting afterload), peak inspiratory pressure (PIP), and oxygenation (SaO (2)) were also recorded. RESULTS: A total of 266 paired measurements (at the time of transpulmonary thermodilution) were taken from 14 animals. During air insufflation, we observed a significant rise in IAP in all animals up to intermittent values of 22 mm Hg. IAP and PIP correlated well (r = 0.666, P < 0.001), with the latter reaching values as high as 45 mbar in one pig, leading to respiratory compromise. Only marginal changes in heart rate, and a continuous, almost significant rise in MAP (due to a significant increase in SVRI) were recorded. We observed a slight increase in GEDVI, predominantly during the initial phase of air insufflation. The cardiac index showed no substantial changes. There were no episodes of hemodynamic instability, nor a decline in SaO (2). CONCLUSIONS: Air insufflation during gastroscopy resulted in a significant increase in IAP. The main clinically relevant finding was a steady increase in SVRI. Major increments in PIP suggest a role of intra-abdominal hypertension in otherwise unexplained respiratory compromise during upper gastrointestinal endoscopy.