Sevdenur Cizginer

Cyst fluid carcinoembryonic antigen is an accurate diagnostic marker of pancreatic mucinous cysts.

Objectives: Endoscopic ultrasound (EUS) may offer a diagnostic tool through the combination of imaging and guided fine-needle aspiration of pancreatic cysts. The purpose of this investigation was to determine the most accurate test for differentiating mucinous from nonmucinous cysts. Methods: The results of EUS imaging, cytology, and cyst fluid biochemical markers were prospectively collected and compared in a large single-center study (776 patients) using histology or malignant cytology as the final diagnostic standard in 198 patients. Results: The mean cyst fluid carcinoembryonic antigen (CEA) was greater in mucinous cysts (4703.0 ng/mL) compared with nonmucinous cysts (25.8 ng/mL) (P = 0.008). When using the optimal cutoff value of 109.9 ng/mL, the CEA was more accurate (86%, receiver operating characteristic area = 0.928) than EUS imaging (48%) and cytology (58%) in predicting a mucinous cyst (P < 0.0001). Malignant cysts had a mean cyst fluid CEA value (2558.2 ng/mL) similar to benign cysts (4700.2 ng/mL). Cytology (75%) more accurately diagnosed malignant cysts than EUS (66%) and CEA (62%) (P < 0.05). Conclusions: Cyst fluid CEA concentration provides a highly accurate test for the diagnosis of a mucinous cyst, but does not distinguish benign from malignant cysts. Cytology is the most accurate test for the diagnosis of a malignant cyst.Abbreviations: EUS - endoscopic ultrasound, CEA - carcinoembryonic antigen, MCN - mucinous cystic neoplasm, IPMN - intraductal papillary mucinous neoplasm

Accuracy of EUS in the evaluation of small gastric subepithelial lesions

BACKGROUND EUS combined with endoluminal resection techniques is increasingly used to provide a definitive diagnosis of small gastric subepithelial lesions seen on standard upper endoscopy. OBJECTIVE To evaluate the accuracy of EUS in diagnosing small gastric subepithelial lesions by using histology as the criterion standard. DESIGN A retrospective study. SETTING Academic tertiary care center. PATIENTS A total of 22 patients (15 women, mean age 62.2 years) with an endoscopically resected gastric subepithelial lesion were included in this 3-year retrospective study. MAIN OUTCOME MEASUREMENTS The size, echogenicity, the layer of origin, and presumptive diagnosis were determined by EUS. The diagnostic accuracy of EUS was determined by using histology as the criterion standard. RESULTS The mean size of the 22 lesions was 13.6 mm (range 8-20 mm). An endoscopic cap band mucosectomy device was used to resect 16 (72.7%) lesions, whereas 6 (27.3%) were resected with a saline solution-assisted and snare technique. Using histology as a criterion standard, we found that the accuracy of the EUS diagnosis was 10 of 22 (45.5%). EUS alone had an accuracy rate of 30.8% and 66.7%, respectively, in the diagnosis of neoplastic and non-neoplastic lesions. LIMITATIONS A single-center, retrospective analysis. CONCLUSION EUS imaging had a low accuracy rate in the diagnosis of gastric subepithelial lesions, and endoscopic submucosal resection should be performed to provide a histologic diagnosis. Resection of small subepithelial lesions of 20 mm or less can be accomplished en bloc with an endoscopic cap band mucosectomy device.

Differentiation of pancreatic cysts with optical coherence tomography (OCT) imaging: an ex vivo pilot study

We demonstrate for the first time that optical coherence tomography (OCT) imaging can reliably distinguish between morphologic features of low risk pancreatic cysts (i.e., pseudocysts and serous cystadenomas) and high risk pancreatic cysts (i.e., mucinous cystic neoplasms and intraductal papillary mucinous neoplasms). In our study fresh pancreatectomy specimens (66) from patients with cystic lesions undergoing surgery were acquired and examined with OCT. A training set of 20 pathology-OCT correlated tissue specimens were used to develop criteria for differentiating between low and high risk cystic lesions. A separate (validation) set of 46 specimens were used to test the OCT criteria by three clinicians, blinded to histopathology findings. Histology was finally used as a ‘gold’ standard for testing OCT findings. OCT was able to reveal specific morphologic features of pancreatic cysts and thus to differentiate between low-risk and high-risk cysts with over 95% sensitivity and specificity. This pilot study suggests that OCT could be used by clinicians in the future to more reliably differentiate between benign and potentially malignant pancreatic cysts. However, in vivo use of OCT requires a probe that has to fit the bore of the pancreas biopsy needle. Therefore, we have developed such probes and planned to start an in vivo pilot study within the very near future.

Feasibility of endoscopic transesophageal thoracic sympathectomy (with video)

BACKGROUND Thoracoscopic sympathectomy is the preferred surgical treatment for patients with disabling palmar hyperhidrosis. Current methods require a transthoracic approach to permit ablation of the thoracic sympathetic chain. OBJECTIVE To develop a minimally invasive, transesophageal endoscopic technique for a sympathectomy in a swine model. DESIGN Nonsurvival animal study. SETTING Animal trial at a tertiary care academic center. SUBJECTS This study involved 8 healthy Yorkshire swine. INTERVENTIONS After insertion of a double-channel gastroscope, a Duette Band mucosectomy device was used to create a small esophageal mucosal defect. A short, 5-cm submucosal tunnel was created by using the tip of the endoscope and biopsy forceps. Within the submucosal space, a needle-knife was used to incise the muscular esophageal wall and permit entry into the mediastinum and chest. The sympathetic chain was identified at the desired thoracic level and was ablated or transected. The animals were killed at the completion of the procedure. MAIN OUTCOME MEASUREMENTS Feasibility of endoscopic transesophageal thoracic sympathectomy. RESULTS The sympathetic chain was successfully ablated in 7 of 8 swine, as confirmed by gross surgical pathology and histology. In 1 swine, muscle fibers were inadvertently transected. On average, the procedure took 61.4+/-24.5 minutes to gain access to the chest, whereas the sympathectomy was performed in less than 3 minutes in all cases. One animal was killed immediately after sympathectomy, before the completion of the observation period, because of hemodynamic instability. LIMITATIONS Nonsurvival series, animal study. CONCLUSIONS Endoscopic transesophageal thoracic sympathectomy is technically feasible, simple, and can be performed in a porcine model.

Feasibility of EUS-guided injection of irinotecan-loaded microspheres into the swine pancreas

BACKGROUND LC beads (Biocompatibles International plc) are designed for the time-released delivery of the chemotherapeutic agent irinotecan into focal, hypervascularized, hepatic tumors. OBJECTIVE To determine the feasibility of EUS-guided injection of LC beads (with/without irinotecan) into the swine pancreas. DESIGN Survival animal study. SETTING Academic center. SUBJECTS This study involved 12 Yorkshire swine. INTERVENTION LC beads without irinotecan and loaded with up to 300 mg of irinotecan were injected under EUS guidance with a 19-gauge needle into the tail of the pancreas. CT scanning and necropsy with histology were performed at day 7. MAIN OUTCOME MEASUREMENTS Feasibility of the injections, gross and microscopic evidence of pancreatic inflammation, and clinical tolerance by the animals. RESULTS After injection of LC beads with/without irinotecan, in 10 of 12 animals an intrapancreatic, hyperechoic focus with an average diameter of 2.2 cm was visible by EUS, and a hypodense area in the tail of the pancreas was visible by contrast CT. In 2 animals (1 with irinotecan and 1 without) no beads were seen on CT. In 10 of 12 animals, a depot of beads was located in the tail of the pancreas on gross inspection and histology. Drug depot with only localized pancreatic tissue reactions was seen on histopathologic review. LIMITATIONS Animal study. CONCLUSION The EUS-guided injection of LC beads (with/without irinotecan) into the pancreas of the pig is feasible and safe. This technique is a potential minimally invasive local treatment option for locally advanced pancreatic cancer.

Endoscopic transesophageal mediastinal lymph node dissection and en bloc resection by using mediastinal and thoracic approaches (with video)

BACKGROUND The criterion standard for sampling mediastinal lymph nodes is cervical mediastinoscopy. Current methods that require transthoracic or cervical incisions can result in significant postoperative pain. OBJECTIVE To determine the feasibility of a novel, transesophageal endoscopic technique for mediastinal lymph node dissection and en bloc resection. DESIGN Nonsurvival and survival animal study. SETTING Animal trial at a tertiary-care academic center. SUBJECTS This study involved 12 Yorkshire swine. INTERVENTION An endoscopic cap band mucosectomy device was used to create an esophageal mucosal defect. By using the tip of the endoscope and biopsy forceps, a submucosal tunnel was fashioned, and, within the submucosal space, a hook-knife incised the muscular esophageal wall. The endoscope was then advanced into the mediastinum and chest. Mediastinoscopy and thoracoscopy were performed to identify lymph node stations. Prototype endoscopic devices permitted lymph node dissection prior to removal with an electrocautery snare. A covered prototype stent was placed over the mucosectomy site. MAIN OUTCOME MEASUREMENTS Feasibility of endoscopic transesophageal lymphadenectomy. RESULTS Three lymph nodes (1 para-aortic and 2 right paratracheal) were removed in the 3 nonsurvival swine. Nine swine were survived for 14 days (range 13-14 days) and had a total of 7 lymph nodes (2 para-aortic and 5 paratracheal) removed. Two swine had no endoscopically visible lymph nodes in the mediastinum or chest. Lymph node dissection and resection was successful in all cases where lymph nodes were identified. Lymphadenectomy was completed in a median time of 20.0 minutes (range 8-60 minutes); median total procedure time was 70.0 minutes (range 28-105 minutes). Median lymph node size was 1.1 cm (range 0.6-1.4 cm). LIMITATIONS Animal study. CONCLUSION An endoscopic transesophageal approach can accomplish mediastinal lymph node dissection and en bloc resection and provides architecturally intact lymph node specimens for histologic examination.

Leaks and endoscopic assessment of break of integrity after NOTES gastrotomy: the LEAKING study, a prospective, randomized, controlled trial

BACKGROUND Gastric leak testing after natural orifice transluminal endoscopic surgery (NOTES) gastrotomy closure may help reduce the risk of leaks after transgastric procedures. OBJECTIVE To develop a novel endoscopy-based system to determine the presence of a leak after NOTES gastrotomy and to compare this system prospectively with radiographic leak testing. DESIGN Prospective, randomized, controlled trial. SETTING Academic Medical Center laboratory. SUBJECTS Fifty swine. INTERVENTION During the pretrial phase, an endoscopic system for the measurement of intragastric pressure was developed. In the trial phase, swine with a NOTES gastrotomy were randomized to endoscopic versus radiographic leak testing. If a leak was demonstrated, the gastrotomy was reclosed by using a second-generation prototype T-anchor system. The primary outcome was leak detection after gastrotomy closure. The secondary outcome variables included necropsy findings, peritoneal fluid analysis, histologic examination, and clinical outcome. RESULTS Fourteen swine were included in the pretrial phase and 36 in the randomized trial. Swine were survived for a mean of 9 days postoperatively. Endoscopic pressure monitoring demonstrated a reproducible change in intragastric pressure with insufflation; r = 0.735, P = .001 and r = 0.769, P < or = .000 for the total and maximum pressures, respectively. Post-peritoneoscopy, there was a detectable and significant decrease in the mean total and mean maximum pressures versus baseline (P = .006 and P = .009). There was no significant difference between the radiologic and endoscopic arms in leak detection rate (4/18 vs 3/18, respectively, P = .500). Clinical outcomes and mean weight gain were equivalent. There was 1 operative abdominal wall injury and no deaths. LIMITATIONS Animal study. CONCLUSION Endoscopic pressure monitoring was reproducible, demonstrated the presence of gastric leak, and was as reliable as contrast-based radiographic leak testing.

Optical coherence tomography imaging for cancer diagnosis and therapy guidance

Optical Coherence Tomography (OCT) is an emerging optical technology that has shown great promise for early cancer detection. Using backreflected light to visualize tissue microstructure, OCT can provide information on nuclear size and shape, nuclear-to-cytoplasmic ratio, and the organization and structure of glands. It can also provide functional information, like blood flow, tissue birefringence, etc. These capabilities could potentially be employed in three ways: as a primary diagnostic test to replace biopsy, as a screening tool to direct biopsy, and as a diagnostic tool to guide therapy and monitor therapy response. In this paper we present an application of OCT for pancreatic cancer diagnosis and therapy guidance.