Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Endoscopes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,459 records · Page 81Linked to original sources
PubMed2001

Endoscopic management of foreign bodies in the upper gastrointestinal tract: report on a series of 414 adult patients.

BACKGROUND AND STUDY AIMS: Ingestion of foreign bodies is a common occurrence. Few papers in the literature report experience and outcome at tertiary centers. The aim of this paper is to report the management and the outcomes in 414 patients admitted for suspected ingestion of foreign body between May 1995 and December 1999. METHODS: A plain radiographic film of the neck, chest or abdomen was obtained in the case of radiopaque objects, and in order to rule out suspected perforation: in such cases a computed tomography (CT) study was also performed. All patients were asked to give their informed consent, which was refused by three patients. Anesthesia was always used, either conscious sedation (86.8 %), or general anesthesia in the case of poor patient tolerance (13.2 %). All patients underwent an endoscopic procedure within six hours of admission. A flexible scope was used in all patients and a wide range of endoscopic devices was employed. RESULTS: Foreign bodies were found in 64.5 % of our patients. Almost all were found in the esophagus. The types of foreign body were very different, but they were chiefly food boluses, bones or cartilages, dental prostheses or fish bones. In three patients (1.1 %) it was impossible to endoscopically remove the foreign body, which was located in the cervical esophagus: all these three patients required surgery. No complications relating to the endoscopic procedure were observed, but 30.7 % of patients had an underlying esophageal disease, such as a stricture. Only eight patients required a second endoscopic procedure, performed by a more experienced endoscopist. CONCLUSION: Foreign body ingestion represents a frequent reason for emergency endoscopy. The endoscopic procedure is a successful technique which allows the removal of the foreign bodies in almost all cases without significant complications. Surgery is rarely required.

Adolescent↗
PubMed2001

An assessment of the potential value of endoscopic ultrasound as a cost-minimizing tool in dyspeptic patients with persistent symptoms.

STUDY AIMS: To quantify resource utilization in dyspeptic patients with persistent symptoms and to determine whether using both the endoscopic and ultrasound capabilities of endoscopic ultrasound could reduce costs. METHODS: Consecutive patients with persistent dyspepsia, after a minimum 1-month trial of acid suppression, underwent endoscopic ultrasound (EUS) and upper endoscopy using the GF-UM20 echo endoscope. Assuming EUS could replace imaging tests which had been requested in addition to upper endoscopy, the hypothetical costs of the EUS-based and upper endoscopy-based strategies were compared. RESULTS: 116 patients with persistent dyspepsia underwent EUS, of whom 64.6 % had > or = 2 imaging procedures, most commonly computed tomography (CT) (70.6 %) and abdominal ultrasound (64.7 %). The number of tests did not correlate strongly with any demographic variables. The fiberoptic echo endoscope provided an adequate endoscopic and ultrasound examination but was damaged by retroflexion. Direct hospital costs were lowest for the EUS-based strategy. Total avoidable cost for 116 patients was $ 4137 to $ 14 121 (or $ 36 to $ 122 per patient), depending on whether upper endoscopy was performed in the non-EUS strategies. CONCLUSIONS: Patients with persistent dyspepsia may undergo multiple abdominal imaging procedures. Clinical variables do not predict the need for additional testing. An EUS-based strategy may reduce overall costs if it prevents additional testing.

Cost-Benefit Analysis↗
PubMed2001

Piecemeal endoscopic aspiration mucosectomy for large superficial intramucosal tumors of the stomach.

BACKGROUND AND STUDY AIMS: As endoscopic techniques continue to develop, endoscopic mucosal resection is increasingly being used in the treatment of intramucosal gastric tumors. The aim of this study was to explore the feasibility of piecemeal endoscopic aspiration mucosectomy for large superficial intramucosal tumors of the stomach. PATIENTS AND METHODS: The study group consisted of five consecutive patients with large superficial intramucosal tumors of the stomach, 4 cm or more in diameter. Piecemeal endoscopic aspiration mucosectomy using a cap-fitted panendoscope was carried out. The initial resection was undertaken at the oral side of the lesion. Subsequent resections were carried out along the anal margin of the previous resection site, until the marks around the boundary of the tumor completely disappeared. RESULTS: The shape of the tumors was slightly elevated in four cases and slightly depressed in one. The mean diameter of the tumors was 4.8 cm. The diameters of the resected specimens ranged from approximately 1.0 cm to 2.3 cm. The numbers of piecemeal resection procedures needed per lesion ranged from five to 18 (mean 11). The visual field was well ensured by the cap, and the tumors were macroscopically completely resected without any complications in all patients. The final histological diagnoses in the specimens were adenoma in one case and mucosal carcinoma in adenoma in four. One patient had residual or recurrent tumor, and received full treatment with additional endoscopic procedures. CONCLUSIONS: Piecemeal endoscopic aspiration mucosectomy is a simple and very useful technique for treating large superficial intramucosal tumors of the stomach.

Adenoma↗
PubMed2001

Endoscopic circumferential esophageal mucosectomy in a porcine model: an assessment of technical feasibility, safety, and outcome.

BACKGROUND AND STUDY AIMS: Endoscopic mucosectomy has been performed for early cancers and dysplastic lesions < or = 2 cm in diameter. The feasibility and safety of mucosectomy for circumferential lesions of the esophagus is uncertain. The aim of this study was to determine the technical feasibility, as well as the short and long-term complication rates, with circumferential endoscopic mucosectomy of the distal esophagus in the pig. MATERIALS AND METHODS: Circumferential endoscopic mucosectomy of the distal 3 cm of the esophagus was performed in four pigs, using a cap mucosectomy device. The animals were sacrificed after 30, 50, 70, and 90 days to assess mucosal regeneration and stricture formation. RESULTS: The procedure time for circumferential endoscopic mucosectomy was 15-30 min. Circumferential endoscopic mucosectomy was technically feasible and without short-term complications. Videotapes of all resections were reviewed to ensure that complete removal of the mucosa was achieved. All mucosectomy specimens underwent histological evaluation. The specimens included the mucosa alone in three of the pigs. Some of the specimens in the fourth pig included a superficial layer of muscularis propria. This pig failed to thrive. Macroscopic examination of the dissected esophageal specimens from the healthy pigs revealed a well-healed, normal-appearing esophagus, whereas a stenosis of 4 x 10 mm was observed in the distal esophagus of the pig that failed to thrive. CONCLUSIONS: Circumferential endoscopic mucosectomy of the porcine distal esophagus is feasible and safe. An adequate submucosal saline cushion is essential to prevent stenosis due to deep injury.

Animals↗
PubMed2001

Endoscopic snare excision of large pedunculated colorectal polyps: a new, safe, and effective technique.

BACKGROUND AND STUDY AIMS: The endoscopic polypectomy of large pedunculated polyps can have serious complications, such as hemorrhage, which has an incidence of about 2 %. We describe here a new, safe, and effective technique of endoscopic polypectomy for the treatment of large pedunculated colorectal polyps using a standard detachable diathermic snare. PATIENTS AND METHODS: 35 patients (18 men, 12 women; mean age 67.3, range 35 - 82), with 43 pedunculated colorectal polyps, of benign appearance and of size 3 cm or larger (range 3 - 5 cm) on colonoscopy, were included in our study. The polypectomy was performed in two steps: a) we first placed a polypectomy snare round the middle of the stalk, as a prophylactic measure to prevent postpolypectomy bleeding, and we then took out the colonoscope without removing the snare after dismantling it and blocking with a clip; b) endoscopic polypectomy was done using a second polypectomy snare, and transecting the stalk of the polyps at 2 mm above the first snare. The first polypectomy snare was left in place, and the patients were discharged within 3 hours of endoscopic polypectomy. The first polypectomy snare sloughed off spontaneously and slipped down the anus, being evacuated within 4 days following the endoscopic polypectomy. RESULTS: The ensnared polyps were located in the rectosigmoid region (n = 27), and the descending (n = 13) and transverse colon (n = 3). Complete ensnarement of the head of the polyp with a single endoscopic treatment was obtained in all cases. In addition, no procedural or delayed bleeding was noted during a 6-month follow-up. CONCLUSIONS: Our technique allows us to overcome the risk of bleeding, since the use of a standard diathermic snare makes it easier to obtain optimal tightness. Moreover, this technique is cheaper than the use of the standard detachable snare currently available (the cost of the snares being $50.52 compared with $189.47).

Adult↗
PubMed2002

Virtual endoscopy for planning neuro-endoscopic intraventricular surgery.

To evaluate the usefulness of virtual endoscopy (VE) in planning neuroendoscopic intraventricular surgeries, the technique was applied in 20 of 22 consecutive procedures. Thirteen endoscopic third ventriculostomies (ETV) in 12 patients, 3 endoscopic colloid cyst removals, 1 third ventricular arachnoidal cyst fenestration, 1 endoscopic ventricul-cysto-cisternostomy (suprasellar arachnoidal cyst), 1 endoscopic tumor biopsy, one third ventricular gross total tumor removal and 2 septostomies at the foramen of Monro due the septal occlusion were performed. Contrast medium-enhanced MR images (3DMPRAGE, Siemens, Germany) were semi-automatically segmented with a surface-rendering technique ("Navigator" software, General Electric Medical, Buc, France) to produce the virtual endoluminal views. Surgery was performed with cerebral ventriculoscopes by Wolf (Richard Wolf, Knittlingen, Germany). VE was feasible in all patients and the virtual endoscopic images were comparable with the real intraventricular views obtained by standard rod lens systems. After contrast medium administration intra- and paraventricular vessels such as the thalamocaudate vein, the septal veins, the basilar artery and its branches (distal BA complex) and the choroid plexus were identified on the virtual endoscopic images. In 8 patients, the additional anatomic information provided by VE profoundly influenced surgical planning. VE provides the neurosurgeon with additional morphological information supporting the planning process of neuroendoscopic intraventricular surgeries, contributing to the safety of the procedures.

Adolescent↗
PubMed2002

Endoscopic reverse third ventriculostomy via the cisterna magna: anatomical study and proposal of a novel procedure.

Basilar artery injury has been known as a potential lethal complication of endoscopic third ventriculostomy. In order to avoid this complication, endoscopic reverse third ventriculostomy via a trans-cisterna-magna route was studied. A cadaveric study was performed for navigation of a flexible endoscope through the cisterna magna. Three fresh, unfixed cadavers were used for this endoscopic navigation. In the prone position, a small vertical paramedian skin incision is made at the mid-portion of the posterior neck. An 11-mm threaded plastic tube is inserted towards the posterior arch of the atlas. After a partial hemilaminectomy of the atlas, a flexible endoscope is introduced into the cisterna magna and is navigated cephalad along the vertebrobasilar artery to the inferior aspect of the floor of the third ventricle. Through the working channel of a fiberscope, third ventriculostomy is performed in a reverse direction. Additional detailed anatomy was studied in fixed cadaveric head specimens with a rigid rod-lens endoscope for anatomic orientation. A novel technique of a trans-cisterna-magna reverse third ventriculostomy was studied in cadaveric specimens. This technique may avoid basilar artery injury which occurs occasionally during conventional third ventriculostomy.

Basilar Artery↗
PubMed2002

Comparison of the exposure obtained by endoscope and microscope in the extended trans-sphenoidal approach.

OBJECTIVE: Trans-sphenoidal surgery is often combined with other approaches for the treatment of middle cranial base tumors. By combining a maxillotomy with trans-sphenoidal approach, significantly wider exposure to these regions is gained. However, endoscope-assisted techniques have also been used for sellar and parasellar and upper clival regions. METHODS: An extended trans-sphenoidal approach was performed on 10 cadaver heads using the operating microscope and was repeated with a 0-degree endoscope. The mean horizontal and vertical distances were measured and pictured for each technique, and both distances were compared using a parametric paired Student's t-test. RESULTS: The mean horizontal distances in the 10 specimens were 19.5 +/- 1.8 mm by microscope and 27.5 +/- 2.2 mm by endoscope, and the mean vertical distances were 25.8 +/- 1.9 mm by the microscope and 34.5 +/- 3.5 mm by the endoscope. CONCLUSION: The aim of this study was to quantify the amount of exposure obtained with an extended trans-sphenoidal approach and to compare both endoscopic and microscopic techniques. Using the endoscope in conjunction with the operating microscope may provide additional exposure and better access in skull base surgery.

Journal Article↗
PubMed2003

[Oropharyngeal vocal tract space during singing--comparison of tactile-kinesthetic and auditory perception with objective endoscopic findings].

BACKGROUND: In this study we compared the perceived diameter of the vocal tract's oropharyngeal part with the diameter that was determined endoscopically. METHODS: 28 singers (13 male, 15 female) were examined with transnasal fiberscopic pharyngoscopy while singing the vowels /a/, /i/ and /u/ in 4 different timbres (normal, opened, covered, dumpled) and 3 different pitches (chest/modal register, subjective comfortable pitch for singing, head/falsetto register). The tactile-kinesthetic and auditive rating of the singers, the auditive rating of a singing teacher and the visual-endoscopic analysis of three laryngologists were compared. RESULTS: The tactile-kinesthetic and auditory self-perception of the singers was quite different from the auditive perception of a singing teacher and visual endoscopic findings of the laryngologists. The singers had the impression that the different singing timbres (normal, opened, covered, dumpled) influence oropharyngeal vocal tract space during singing. They judged the vowel itself and the pitch as having very little influence. Based on his auditory perception, the singing teacher also rated that the timbre plays an important role for the oropharyngeal vocal tract space but he found vowels to be the parameter with the greatest impact. Via visual endoscopic examination we found that, among the three parameters (vowel, timbre, pitch), the different vowels are most influential on the oropharyngeal vocal tract space. Analysis of video sequences revealed that pitch and timbre are less important. CONCLUSION: Subjective tactile-kinesthetic and auditory perception of the singers differs from auditory perception of the singing teacher as well as from endoscopic findings. The endoscopically determined oropharyngeal vocal tract space during singing the vowels /i/ or /u/ tends to be larger compared to the oropharyngeal vocal tract space while singing the vowel /a/.

Adult↗
PubMed2003

Long-term results of endoscopic removal of large colorectal adenomas.

BACKGROUND AND STUDY AIMS: Endoscopic removal of large colorectal polyps has not been widely accepted. The aims of this study were to evaluate our longterm experiences justifying endoscopic resection technique as the treatment of choice. PATIENTS AND METHODS: During a period of 12 years, 288 patients with a total of 302 polyps larger than 3 cm in diameter were treated endoscopically. 224 polyps were sessile and 78 pedunculated. Sessile polyps were removed using the piecemeal technique. Surgery was recommended in patients with unfavorable histology. Patients with favorable histology were followed up at 3 - 6 month intervals in the first year and then every 1 - 2 years. RESULTS: A total of 184 patients with sessile polyps were followed up for at least 6 months. Recurrence rate of 166 benign polyps was 17 % (29/166). Only two patients had malignant recurrence. 8 of 18 patients with malignant polyps underwent surgery while 10 were unfit for surgery. 8 of these patients remained free of recurrence. CONCLUSIONS: Previous concerns about endoscopic removal of large colorectal polyps are no longer justified. The results of this study showed that endoscopic resection of large colorectal polyps is safe and effective. In patients with high operative risk, endoscopic removal may be adequate.

Adenoma↗
PubMed2003

Clinical evaluation of combined endoscopic variceal ligation and sclerotherapy of gastric varices in liver cirrhosis.

BACKGROUND AND STUDY AIMS: Endoscopic injection sclerotherapy (EIS) using cyanoacrylate and balloon-occluded retrograde transvenous obliteration (B-RTO) are the main procedures used to treat gastric varices. However, neither technique is free of problems. EIS for gastric varices may cause embolism in other organs; B-RTO requires a gastrorenal shunt and may aggravate esophageal varices. We have developed a combined form of endoscopic therapy involving band ligation and sclerotherapy which is an effective and safe procedure for treating gastric varices. PATIENTS AND METHODS: Fifty-six patients with gastric varices and liver cirrhosis were treated at Almeida Memorial Hospital from June 1997 to May 2002 using the combined procedure. Each gastric varix was tightly ligated with O-rings, and 1 % polidocanol was injected into the submucosa around the ligated varix. If necessary, additional sclerotherapy was carried out after the initial treatment. RESULTS: The rate of hemostasis for variceal bleeding was 100 %, and no critical complications were noted. Complete disappearance of the gastric varices was observed endoscopically in all cases. Computed tomography showed that collateral vessels outside the gastric wall were not occluded by the treatment. Endoscopic follow-up examinations were carried out, and gastric varices recurred in seven patients (12.5 %). Only two of the patients (3.6 %) had a small amount of oozing bleeding. Additional endoscopic variceal ligation (EVL) and/or EIS were performed in these seven cases, and none of the patients died as a result of a bleeding gastric varix. CONCLUSIONS: The combined procedure was easily performed immediately after endoscopic examination, and required no special apparatus. It was found to be a safe and effective method of treating gastric varices.

Adult↗
PubMed2003

Endoscopic-assisted craniofacial resection of esthesioneuroblastoma: minimizing facial incisions--technical note and report of 3 cases.

The surgical management of esthesioneuroblastoma with anterior skull base involvement has traditionally been craniofacial resection, which combines a bifrontal craniotomy with a transfacial approach. The latter usually involves a disfiguring facial incision, mid-facial degloving, lateral rhinotomy, and/or extensive facial osteotomies, which may be cosmetically displeasing to the patient. The advent of angled endoscopes has provided excellent magnification and illumination for surgeons to remove tumors using minimally invasive techniques. The authors describe their experience with three cases of esthesioneuroblastoma, which were surgically removed using a transnasal endoscopic approach, avoiding transfacial incisions. Preoperative radiographs were reviewed and tumors were staged according to the Kadish staging system. One patient had a recurrent esthesioneuroblastoma (Kadish stage B), which was removed entirely through a transnasal endoscopic approach. Two patients had intracranial extension (Kadish stage C), which were resected with a combined approach, endoscopically from below and a bifrontal craniotomy from above, to remove intracranial disease. All patients underwent reconstruction of the anterior skull base. Esthesioneuroblastomas confined to the nasal and paranasal cavities (Kadish stage A and B) were readily accessible through the transnasal endoscopic approach. If there was significant intracranial disease (Kadish stage C), adding a bifrontal craniotomy provided excellent exposure for complete resection of involved tumor. All patients underwent complete tumor resection with negative margins. None developed a cerebrospinal fluid (CSF) leak. The endoscopic-assisted craniofacial approach for the surgical management of esthesioneuroblastomas provides excellent exposure, adequate visualization, and the cosmetic benefit of avoiding an external facial incision.

Adult↗
PubMed2004

Atypical endoscopic features of rectal carcinoids.

BACKGROUND AND STUDY AIMS: It is not normally difficult to diagnose carcinoid tumors (well-differentiated endocrine neoplasms) of the rectum endoscopically, as they usually have a characteristic appearance. However, little is known about the atypical endoscopic findings in some rectal carcinoids and the present study was performed to analyze these. PATIENTS AND METHODS: The endoscopic findings in 67 consecutive patients with rectal carcinoids (37 men, 30 women; age range 23 - 76) were analyzed retrospectively. RESULTS: Tumor size ranged from 2 mm to 30 mm (average 7.4 mm). Of the 67 patients, 52 (78 %) displayed the characteristic endoscopic findings of smooth, round, sessile elevations covered with normal-appearing or yellow-discolored mucosa; in 15 (22 %) there were one or more atypical endoscopic findings. These included a semipedunculated appearance (n = 6), hyperemia (n = 5), a central depression (n = 6), erosion (n = 5), and ulceration (n = 4). Atypical findings were noted in none of 20 carcinoids &lambda< 5 mm in diameter; in six (20 %) of the 30 carcinoids between 5 mm and 9 mm; in six (43 %) of the 14 carcinoids between 10 mm and 19 mm; and in three (100 %) of the three carcinoids >/= 20 mm in diameter ( P < 0.001). Invasion into the muscularis propria or metastasis to the liver or lymph nodes occurred in three of the four patients with ulceration, but it was confirmed in only one of the 63 patients without ulceration ( P < 0.001). CONCLUSIONS: Atypical endoscopic appearances of rectal carcinoids are observed more frequently as the size of the tumor increases and a finding of ulceration may have a prognostic value.

Adult↗
PubMed2004

An evaluation of colorectal endoscopic mucosal resection using high-magnification chromoscopic colonoscopy: a prospective study of 1000 colonoscopies.

BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection provides an alternative to surgery for resection of sessile and flat colorectal lesions. High-magnification chromoscopic colonoscopy may allow early detection and anticipate histological diagnosis by identifying colonic crypt patterns. The aim of the present study was to assess the efficacy and safety of en-bloc endoscopic mucosal resection with high-magnification chromoendoscopy in the management of sessile and flat colorectal lesions </= 20 mm. PATIENTS AND METHODS: A single endoscopist using high-magnification chromoendoscopy prospectively examined 1000 patients attending for routine colonoscopy. Patients were selected for inclusion in the study if they were considered to be at high risk for underlying colorectal neoplasia or polyps. Within the study period, 1000 patients (29 %) qualified for entry from a total of 3480 colonoscopies conducted in our institution. Endoscopic mucosal resection was carried out in appropriate flat and sessile lesions. RESULTS: Endoscopic mucosal resection was carried out in 599 lesions. Complete histological resection was confirmed in 576 (96 %). Perforation occurred in one patient (0.2 %) and bleeding in 12 (2 %). A total of 254 lesions (40 %; excluding hyperplasia/metaplasia) were flat or depressed, and 374 (60 %) were sessile. Fifty-eight flat lesions (23 %) contained high-grade dysplasia or beyond, compared to 33 sessile lesions (9.0 %; P = 0.001). After resection, 21 lesions were upgraded histologically, with 17 being defined as adenoma with high-grade dysplasia or beyond. CONCLUSIONS: This study confirms that flat adenomas and carcinomas occur in the West and demonstrates the malignant potential of such lesions, which can be managed successfully using endoscopic techniques. Endoscopic mucosal resection with high-magnification chromoscopy is a safe and effective form of treatment for sessile or flat colorectal lesions. Complete resection can improve the accuracy of histopathological diagnosis. However, colonoscopists require training in these procedures in order to improve the rate of colorectal cancer detection.

Adenoma↗
PubMed2004

Short-term and long-term results of endoscopic balloon dilation for achalasia: 12 years' experience.

BACKGROUND AND STUDY AIMS: This retrospective study reports 12 years' experience with pneumatic dilation treatment in patients with achalasia and attempts to define factors capable of predicting failure of endoscopic dilation. PATIENTS AND METHODS: Consecutive patients with achalasia who received endoscopic balloon dilation were studied retrospectively. Repeat dilation was carried out if dysphagia persisted or recurred. A structured symptom score questionnaire (the Eckardt score) was conducted by phone with patients who had received dilation and had been followed up for more than 2 years. Failure was defined as the presence of significant dysphagic symptoms after more than two repeat dilations. Data for the first 2 years (short-term) and for the subsequent follow-up (long-term) were analyzed. RESULTS: From 1989 to 2001, 66 patients underwent endoscopic balloon dilation for achalasia; three perforations (4.5 %) occurred, with no mortalities. Dysphagic symptoms significantly improved 12 weeks after the procedure ( P < 0.05). Fourteen patients (20 %) required a second dilation procedure within a median of 7 months (range 1 - 52 months), and 13 of them underwent repeat dilations within the first 2 years. Five patients (7.5 %) required further surgical or endoscopic therapy. Fifty-eight patients received pneumatic dilation for more than 2 years; 32 (55 %) responded to the questionnaire. The mean dysphagia score was 1.7 (SD 1.2), with only five patients (16 %) having significant dysphagic symptoms during a median follow-up period of 55 months (range 26 - 130 months). The cumulative success rates for pneumatic dilation after 5 and 19 years were 74 % and 62 %, respectively. Cox regression analysis identified small balloon size (30 mm) as the only significant factor capable of predicting failure of endoscopic dilation ( P = 0.009; relative risk 5.3; 95 % confidence interval, 1.7 to 40.9). CONCLUSIONS: Endoscopic balloon dilation is an effective treatment for achalasia, with minimal morbidity (60 % experience long-term benefit).

Adolescent↗
PubMed2005

Endoscope-assisted microsurgery of large vestibular schwannomas.

AIMS: The application of endoscope-assisted microsurgery in the treatment of small or medium-sized vestibular schwannomas is of proven value. The goal of our study is to evaluate its usefulness in cases of large schwannomas. PATIENTS AND METHODS: Eighteen patients were included in this prospective study. Their average tumor diameter was 3.9 cm. The retrosigmoid approach was used in all cases. The endoscope was applied during all stages of tumor removal. RESULTS: The facial nerve was visualized endoscopically at early stages of surgery in 9 patients and the abducent nerve in 7 patients. The source of bleeding was identified in 1 case. Tumor remnants in the region of the fundus of the internal auditory canal after apparently total removal were identified in 2 cases. Exposed and unobliterated temporal bone air cells were not observed. DISCUSSION: Even in cases of large schwannomas, the location of the facial nerve can be determined endoscopically early in the procedure. The application of endoscope-assisted microsurgery increases the rate of cranial nerve preservation and of total tumor removal. Although the application of the endoscope did not provide useful information in some cases, it is a safe procedure that did not lead to any complications and/or to considerable prolongation of the operative time. Its application is justified in all cases.

Adult↗
PubMed2005

Biomechanical rationale of endoscopic decompression for lumbar spondylolysis as an effective minimally invasive procedure - a study based on the finite element analysis.

We evaluated the biomechanical behavior of the endoscopic decompression for lumbar spondylolysis using the finite element technique. An experimentally validated, 3-dimensional, non-linear finite element model of the intact L3 - 5 segment was modified to create the L4 bilateral spondylolysis and left-sided endoscopic decompression. The model of Gill's laminectomy (conventional decompression surgery of the spondylolysis) was also created. The stress distributions in the disc and endplate regions were analyzed in response to 400 N compression and 10.6 Nm moment in clinically relevant modes. The results were compared among three models. During the flexion motion, the pressure in the L4/5 nucleus pulposus was 0.09, 0.09 and 0.16 (MPa) for spondylolysis, endoscopic decompression and Gill's procedure, respectively. The corresponding stresses in the annulus fibrosus were 0.65, 0.65 and 1.25 (MPa), respectively. The stress at the adjoining endplates showed an about 2-fold increase in the Gill's procedure compared to the other two models. The stress values for the endoscopic and spondylolysis models were of similar magnitudes. In the other motions, i. e., extension, lateral bending, or axial rotation, the results were similar among all of the models. These results indicate that the Gill's procedure may lead to an increase in intradiscal pressure (IDP) and other biomechanical parameters after the surgery during flexion, whereas the endoscopic decompression did not change the segment mechanics after the surgery, as compared to the spondylolysis alone case. In conclusion, endoscopic decompression of the spondylolysis, as a minimally invasive surgery, does not alert mechanical stability by itself.

Biomechanical Phenomena↗
PubMed2005

Contrast-enhanced endoscopic ultrasound with low mechanical index: a new technique.

AIM: Recent advances in technology have supported the development of new endoscopic ultrasound systems making it possible to use low MI contrast-enhanced imaging techniques (wide band harmonic imaging done with endoscopic ultrasound is currently at a preliminary stage). We now report on the first use of contrast-enhanced, low mechanical index, real-time endoscopic ultrasound (CELMI-EUS) in six patients using prototype technology. MATERIALS AND METHODS: CELMI-EUS was performed using an electronic echo-endoscope HITACHI/Pentax EG-3830UT and adapted dynamic contrast harmonic wide-band pulsed inversion software with low mechanical index (MI = 0.09 - 0.25) before and up to 180 seconds after injection of SonoVue (4.8 mL) in six patients. RESULTS: Adequate visualisation of the arterial and portal venous phases was achieved in all patients. The pancreas and liver were studied thereafter. In contrast to the satisfactory visualisation of these vessels, enhancement of the left liver lobe was sufficient only in 4 patients. In the remaining 2 patients with liver cirrhosis, the enhancement was less pronounced in contrast to the strong enhancement of the hepatic artery and portal vein. CONCLUSION: Recent advances in technology have supported the development of new echo-endoscopic systems making it possible to use real-time, low mechanical index, contrast-enhanced imaging techniques with endoscopic ultrasound. We have preliminarily shown that arterial, portal venous and parenchymal contrast enhancement is possible.

Adult↗