Endoluminal Ultrasonography Research Articles

Contemporary status of diagnostic endoluminal ultrasound and optical coherence tomography in the ureter

AbstractObjectiveTo evaluate via a review of published literature, the efficacy of endoluminal ultrasound (ELUS) and optical coherence tomography (OCT) in the following ureteric diseases: urolithiasis, upper tract urothelial carcinoma, stricture disease and pelvic‐ureteric junction obstruction (PUJO).Patients and methodsUreteric high‐frequency ELUS provides 360° imaging, to a depth of 20 mm, and has been demonstrated to assess ureteric stricture length, degree of fibrosis and aetiology. OCT produces high‐quality images with a penetration depth of 2 mm. ELUS has proven to be useful at the time of endopyelotomy for PUJO as it can identify crossing vessels, some not detectable on CT angiography, allowing the urologist to avoid these when making their incision. Ureteric ELUS may be utilised for submucosal ureteric stones as they are highly visible. Endoluminal ultrasound may be deployed in the case of known sub‐mucosal urolithiasis when the ureter appears stone‐free. It may help identify sub‐mucosal stones or stones within diverticulum.ResultsEndoluminal ultrasound has been analysed for its use in determining muscle‐invasive urothelial carcinoma of the ureter. The PPV for ≥pT2 was only 16.7% in one study of six patients with MIBC and 76.2% in 21 patients with <pT2 disease. Analysis of OCT for staging UTUC during ureteroscopy and biopsy demonstrated sensitivity for tumour invasion of 100% and specificity of 92%, 83% of lesion staging matched with histological analysis. Imaging analysis did not match histology in three patients with large exophytic tumours that exceeded the OCT depth penetration. Due to its superficial penetration, OCT cannot reliably stage large tumours.ConclusionsUreteric ELUS has been reported to be a useful tool in endopyelotomy, urolithiasis and stricture disease. The staging of ureteric urothelial carcinoma remains unsatisfactory with current imaging techniques and biopsy methods, and, based on the current literature, ELUS does not appear to have a strong enough PPV to determine muscle invasion. Ureteric OCT may be a useful tool in the future staging of upper tract urothelial carcinoma, particularly in differentiating the stage of small tumours. Further studies are needed in this area.

Current methods facilitating diagnosis of upper tract urothelial carcinoma: a comprehensive literature review.

Currently, kidney-sparing surgeries are considered the preferred approach in low-risk tumours and in selected high-risk patients. Therefore, accurate diagnosis of UTUC is crucial for further management. The purpose of this review is to summarize available methods facilitating the diagnosis of upper tract urothelial carcinoma (UTUC). Recent articles propose numerous techniques of UTUC diagnosis. In this review, imaging, as well as, urine-based and endoscopic methods have been described and assessed. Regarding imaging, computed tomography urography remains a gold standard, while PET is superior in search for small lesions and nodal metastases. However, contrast-enhanced ultrasonography also shows promise. On the contrary, available urine tests, such as urinary cytology, fluorescent in-situ hybridization, Xpert, DNA methylation analysis, urine-based liquid biopsy, p16/Ki-67 dual immunolabelling, ImmunoCyt and NMP22 are either poorly researched, or not accurate enough to use solely. Finally, during ureterorenoscopy, photodynamic diagnosis and narrow-band imaging can facilitate proper visualization of the tumor. Endoluminal ultrasonography and confocal laser endomicroscopy can potentially improve staging and grading of UTUC. Also, the 'form tackle' biopsy should be performed using a basket in papillary lesions and cold-cup biopsy of flat or sessile lesions. Even though cryobiopsy shows promise in UTUC diagnosis, in-vivo studies are necessary before it is introduced into clinical practice.

Detection of Mice Colorectal Tumors by Endoluminal Ultrasound Biomicroscopic Images and Quantification of Image Augmented Gray Values Following Injection of VEGFR-2 Targeted Contrast Agent

Ultrasound biomicroscopy (UBM) is a noninvasive imaging technique that can be applied in detecting colonic tumors and, once associated with an ultrasound contrast agent (UCA), can identify the molecular expression of cancer-related biomarkers, such as the vascular endothelial growth factor receptor 2 (VEGFR-2). The present work aimed to detect colonic tumors and quantify augmented gray values of endoluminal UBM (eUBM) images from colonic tumors following the injection of VEGFR-2 targeted UCA (VEGFR2-UCA) into a mouse model of colorectal cancer. A 40 MHz miniprobe catheter inserted through the biopsy channel of a pediatric flexible bronchofiberscope was used to obtain colonoscopic and B-mode eUBM images simultaneously. Seventeen tumor-bearing mice had their colons inspected and six of them were subjected to a VEGFR2-UCA injection to predict VEGFR-2 expression. All animals developed distal colon tumors and eUBM was able to detect all of them and also to characterize the tumors, with 71.4% being in situ lesions and 28.6% being tumors invading the mucosa + muscularis mucosae + submucosa layers, as confirmed by histopathology. After VEGFR2-UCA injection, gray values from the eUBM tumoral images increased significantly (p < 0.01). Tumor sites with increased eUBM image gray values corresponded to areas with increased VEGFR-2 expression, as confirmed by immunohistochemistry. The results confirm eUBM as a powerful noninvasive and real-time tool for detecting colon tumor and its invasiveness and once associated with VEGFR2-UCA may become a tool for the detection of VEGFR-2 expression in colonic tumors.

Accuracy of High-Frequency Endoluminal Ultrasonography for Clinical Staging of Upper Tract Urothelial Carcinoma.

Staging of upper tract urothelial carcinoma (UTUC) remains a dilemma due to imaging and biopsy limitations leading to understaging. We seek to determine the accuracy of endoluminal ultrasound (ELUS) for clinical staging of UTUC. Patients evaluated for UTUC underwent retrograde pyelography, ureteroscopy, and ELUS. ELUS was performed using mechanical radial scanning at 20 MHz in B-mode with a 5F probe. Cine clips were evaluated by 2 radiologists blinded to ureteroscopic and pathology findings. Results were compared to pathology from nephroureterectomy. Inclusion criteria were patients who underwent nephroureterectomy without pretreatment or managed endoscopically for cTa-1 disease and were without recurrence for >1 year. From 2008 to 2013, 53 patients underwent ELUS without complication. Twenty-seven patients met inclusion criteria with conclusive ELUS imaging. ELUS accurately identified 16 of 21 patients with non-muscle invasive (MI) disease (18 pTa, 2 pT1, 1 CIS) and 1 of 6 patients with at least MI disease (2 pT2, 4 pT3). For MI disease, the positive predictive value (PPV), negative predictive value, and accuracy was 76.2%, 16.7%, and 63%, respectively, while for non-organ confined (OC) disease results were 0%, 81.8%, and 66.7%, respectively. With current technique and instrumentation, ELUS may prove useful in select cases to confirm findings of non-MI and OC disease. However, it has insufficient PPV for stage pT2-3 disease. Further studies and better instrumentation are needed before incorporation into clinical practice.

The treatment of early rectal cancer in the era of adjuvant and neo-adjuvant therapy

The accurate staging of rectal cancer improves the stratification of patients for adjuvant therapy. Staging of tumor with endoluminal ultrasonography (EUS) shows a good correlation with histology (κ = 0.85; 95% confidence interval 0.76-0.95). Overall pT and pN stage accuracy of EUS was 92% and 65% respectively. The staging of local disease can be further augmented by EUS guided fine needle aspiration of extra rectal lesions lying within or outside of the mesorectum. In a systematic review of local excision after neoadjuvant therapy a total of 22 unique studies reporting on 1068 patients were analysed. At a median follow-up of 54 months, ypT0 tumours had a pooled local recurrence rate of 4% and a median disease-free survival rate of 95%. Outcomes for ≥ ypT1 tumours were much worse with pooled local recurrence and disease-free survival of 22% and 68%, respectively. In a review of 22 studies, 804 patients who underwent local excision followed by adjuvant therapy either for unfavourable histology, prohibitive comorbidity or patient choice. the pooled local recurrence was 5.8% for pT1 tumours, 13.8% for pT2 tumours and 33.7% for pT3 tumours. In addition, the response to radiotherapy may be enhanced by aspirin, metformin and statins.

A Novel Synchronous Micro Motor for Intravascular Ultrasound Imaging.

Intravascular ultrasound (IVUS) is an important method for evaluating lumen dimensions and guiding intervention. However, the current IVUS catheter using a proximal motor and flexible drive shaft is easily rotated at an unstable speed when it passes through along bending vessel. One approach to solve this problem is to develop a catheter driven by a distal motor. This paper presents a rotation device incorporating a high-frequency transducer as an attempt to facilitate this approach. A novel micro distal synchronous micro motor with 3.7 mm length and 1.2 mm outer diameter was proposed as an actuator for the IVUS catheter. A 0.5 mm × 0.5 mm Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal 1-3 composite single-element transducer was designed and manufactured. The probe is fixed to the front end of the catheter. The 45° reflector, which is opposite to the probe, was used to steer ultrasound to the tissue. The results showed that the maximum torque and rotation speed of the motor were 2.79 μNm and 275 revolutions per second, respectively, at a driving current of 0.34 A. The maximum angular error was 7° at 0.13 A and 30Hz. The center frequency and -6 dB fractional bandwidth of single element were 34MHz and 72%, respectively. At the center frequency, the two-way insertion loss was 14 dB. The integrated distal motor IVUS catheter, with small dimensions, a good torque, speed stability, and good ultrasound imaging performance, has tremendous potential in blood vessel imaging. The novel structure of the catheter could facilitate endoluminal sonography, reducing risks of the clinical diagnosis.

Ex-vivo study in nephroureterectomy specimens defining the role of 3-D upper urinary tract visualization using optical coherence tomography and endoluminal ultrasound.

Minimal invasive endoscopic treatment for upper urinary tract urothelial carcinoma (UUT-UC) is advocated in patients with low-risk disease and limited tumor volume. Diagnostic ureterorenoscopy combined with biopsy is the diagnostic standard. This study aims to evaluate two alternative diagnostic techniques for UUT-UC: optical coherence tomography (OCT) and endoluminal ultrasound (ELUS). Following nephroureterectomy, OCT, ELUS, and computed tomography (CT) were performed of the complete nephroureterectomy specimen. Visualization software (AMIRA®) was used for reconstruction and coregistration of CT, OCT, and ELUS. Finally, CT was used to obtain exact probe localization. Coregistered OCT and ELUS datasets were compared with histology. Coregistration with three-dimensional CT makes exact data matching possible in this ex-vivo setting to compare histology with OCT and ELUS. In OCT images of normal-appearing renal pelvis and ureter, urothelium, lamina propria, and muscularis were visible. With ELUS, all anatomical layers of the ureter could be distinguished, besides the urothelial layer. ELUS identified suspect lesions, although exact staging and differentiation between noninvasive and invasive lesions were not possible. OCT provides high-resolution imaging of normal ureter and ureter lesions. ELUS, however, is of limited value as it cannot differentiate between noninvasive and invasive tumors.

Clinical value of endoluminal ultrasonography in the diagnosis of rectovaginal fistula.

BackgroundRectovaginal fistula (RVF) refers to a pathological passage between the rectum and vagina, which is a public health challenge. This study was aimed to explore the clinical value of endoluminal biplane ultrasonography in the diagnosis of rectovaginal fistula (RVF).MethodsThirty inpatients and outpatients with suspected RVF from January 2006 to June 2013 were included in the study, among whom 28 underwent surgical repair. All 28 patients underwent preoperative endoluminal ultrasonography, and the obtained diagnostic results were compared with the corresponding surgical results.ResultsAll of the internal openings located at the anal canal and rectum of the 28 patients and confirmed during surgery were revealed by preoperative endosonography, which showed a positive predictive value of 100 %. Regarding the 30 internal openings located in the vagina during surgery, the positive predictive value of preoperative endosonography was 93 %. The six cases of simple fistulas confirmed during surgery were revealed by endosonography; for the 22 cases of complex fistula confirmed during surgery, the positive predictive value of endosonography was 90 %. Surgery confirmed 14 cases of anal fistula and 14 cases of RVF, whereas preoperative endoluminal ultrasonography suggested 16 cases of anal fistula and 12 cases of RVF, resulting in positive predictive values of 92.3 and 93 %, respectively.ConclusionThe use of endoluminal biplane ultrasonography in the diagnosis of RVF can accurately determine the internal openings in the rectum or vagina and can relatively accurately identify concomitant branches and abscesses located in the rectovaginal septum. Thus, it is a good imaging tool for examining internal and external anal sphincter injuries and provides useful information for preoperative preparation and postoperative evaluation.

Restaging of Locally Advanced Rectal Cancer With Magnetic Resonance Imaging and Endoluminal Ultrasound After Preoperative Chemoradiotherapy

Magnetic resonance imaging and endoluminal ultrasound play an important role in the restaging of locally advanced rectal cancer after preoperative chemoradiotherapy, yet their diagnostic accuracy is still controversial. Meta-analysis was performed to estimate the diagnostic performance of MRI and endoluminal ultrasound. Electronic databases from 1996 to March 2012 were searched. Either MRI or endoluminal ultrasound was used to restage rectal cancer after chemoradiotherapy or radiation. T category, lymph node, and circumferential resection involvement were measured. The sensitivity estimate for rectal cancer diagnosis (T0) by endoluminal ultrasound (37.0%; 95% CI, 24.0%-52.1%) was higher (p = 0.04) than the sensitivity estimate for MRI (15.3%; 95% CI, 6.5%-32.0%). For T3-4 category, sensitivity estimates of MRI and endoluminal ultrasound were comparable, 82.1% and 87.6%, whereas specificity estimates were poor (53.5% and 66.4%). For lymph node involvement, there was no significant difference between the sensitivity estimates for MRI (61.8%) and endoluminal ultrasound (49.8%). Specificity estimates for MRI and endoluminal ultrasound were 72.0% and 78.7%. For circumferential resection margin involvement, MRI sensitivity and specificity were 85.4% and 80.0%. To identify the heterogeneity, metaregression was performed on covariates. However, few of the covariates were identified to be statistically significant because of the lack of adequate original data. Accurate restaging of locally advanced rectal cancer by MRI and endoluminal ultrasound is still a challenge. Identifying T0 rectal cancer by imaging is not reliable. Before performing surgery, restaging is important, but some of the T0-2 patients are likely overestimated as T3-4. Both modalities for lymph node involvement are not very good. Magnetic resonance imaging may be a good method to reassess circumferential resection margin.

Preliminary study of endoluminal two-dimensional ultrasonography to evaluate puborectalis muscle of nulliparous women

Objective To investigate the measurement standards and clinical application of observing anatomical morphologies and contractile function of puborectalis muscle on pelvic floor parasagittal plane by endoluminal two-dimensional ultrasonography.Methods The thickness and thickening rate of puborectalis muscle of 78 young nulliparous women were measured on pelvic floor parasagittal plane at three levelsurethral level (anterior),vaginal level (central) and rectal level (posterior),both at rest and during contraction.And the thickening rates of these parts during contraction were compared with each other.Interclass correlation coefficients were calculated to evaluate the consistency of the datas.Results At rest,thickness of anterior part of the left was (9.23 ± 0.20)mm,and that of the right was (8.99 ± 0.20)mm.During contraction,thickness of anterior parts of bilateral puborectalis muscle were significantly thicker than that of central or posterior parts (P ＜0.05).The interclass coefficients were more than 0.93 and 0.83.Conclusions The endoluminal two-dimensional ultrasonography can be used to observe morphologies and contractile function dynamically of puborectalis on pelvic floor parasagittal plane.It is simple,reproducible and worthy of clinical promotion. Key words: Endosonography ; Pelvic floor ; Puborectalis muscle

Volumetric In Vivo Visualization of Upper Urinary Tract Tumors Using Optical Coherence Tomography: A Pilot Study

Knowledge of tumor stage and grade is paramount for treatment decision making in cases of upper urinary tract urothelial carcinoma but this condition cannot be accurately assessed by current techniques. Optical coherence tomography can hypothetically provide the urologist with real-time intraoperative information on tumor grade and stage. In this pilot study we report what are to our knowledge the first results of optical coherence tomography for grading and staging upper urinary tract urothelial carcinoma. Eight consecutive patients underwent ureterorenoscopy for suspicion or followup of upper urinary tract urothelial carcinoma. Optical coherence tomography data sets were intraoperatively obtained from the ureter and renal pelvis. All patients eventually underwent nephroureterectomy. Optical coherence tomography staging was done by visual inspection of lesions found on optical coherence tomography images. Optical coherence tomography grading was done by quantifying optical coherence tomography signal attenuation in mm(-1) on lesions and comparing results with the histopathological diagnosis. The Wilcoxon rank sum test was used for statistical analysis. For 7 in vivo optical coherence tomography diagnoses staging was in accordance with histology. In patient 8 tumor thickness transcended optical coherence tomography imaging depth range and, therefore, invasiveness findings were inconclusive. For grading the median attenuation coefficient for grade 2 and 3 lesions was 1.97 (IQR 1.57-2.30) and 3.53 mm(-1) (IQR 2.74-3.94), respectively (p<0.001). Healthy urothelium was too thin to reliably determine the attenuation coefficient. Optical coherence tomography is a promising, minimally invasive tool for real-time intraoperative optical diagnosis of tumors in the upper urinary tract. Our results warrant future research in a larger sample size to determine the accuracy of grading and staging by optical coherence tomography, and its possible implementation in the diagnostic algorithm for upper urinary tract urothelial carcinoma.

Evaluation in an Animal Model of a Hybrid Covered Metallic Ureteral Stent: A New Design

To evaluate a new design for a hybrid, dynamic, metallic ureteral stent that might avoid the formation of urothelial hyperplasia after ureteral metallic stenting in an experimental study. A total of 30 healthy female pigs were included in the present study, and an experimental obstructive uropathy in the right lumbar ureter was created in each pig. Obstruction was confirmed using percutaneous ultrasonography and retrograde ureteral pyelography and endoluminal ultrasonography 6 weeks after obstructive uropathy model creation. Then, the pigs were randomly distributed into 2 groups. Group 1 underwent standard metallic ureteral self-expanding internally covered stent deployment. Group 2 received a new hybrid metallic ureteral self-expanding internally covered stent. The follow-up period was 6 months. The hybrid metallic ureteral self-expanding internally covered stent group had a lower rate of urothelial hyperplasia (21% vs 70%), reduced stent migration (6.6% vs 33.3%), and a greater success rate after 6 months of follow-up (86.6% vs 47%) compared with the standard metallic ureteral self-expanding internally covered stent deployment group, with statically significant differences between the 2 groups. Our experimental results have indicated that the use of the hybrid metallic ureteral self-expanding internally covered stent in ureteral strictures is feasible, safe, and effective and reduces the formation of urothelial hyperplasia without secondary interventions to maintain ureteral patency.

Prognostic significance of circumferential resection margin involvement following oesophagectomy for cancer and the predictive role of endoluminal ultrasonography

Background:The optimum multimodal treatment for oesophageal cancer, and the prognostic significance of histopathological tumour involvement of the circumferential resection margin (CRM+) are uncertain. The aims of this study were to determine the prognostic significance of CRM+ after oesophagectomy and to identify endosonographic (endoluminal ultrasonography (EUS)) features that predict a threatened CRM+.Methods:Two hundred and sixty-nine consecutive patients underwent potentially curative oesophagectomy (103 surgery alone, 124 neoadjuvant chemotherapy (CS) and 42 chemoradiotherapy (CRTS)). Primary outcome measures were disease-free survival (DFS) and overall survival (OS).Results:CRM+ was reported in 98 (38.0%) of all, and in 90 (62.5%) of pT3 patients. Multivariate analysis of pathological factors revealed: lymphovascular invasion (HR 2.087, 95% CI 1.396–3.122, P<0.0001), CRM+ (HR 1.762, 95% CI 1.201–2.586, P=0.004) and lymph node metastasis count (HR 1.563, 95% CI 1.018–2.400, P=0.041) to be independently and significantly associated with DFS. Lymphovascular invasion (HR 2.160, 95% CI 1.432–3.259, P<0.001) and CRM+ (HR 1.514, 95% CI 1.000–2.292, P=0.050) were also independently and significantly associated with OS. Multivariate analysis revealed EUS T stage (T3 or T4, OR 24.313, 95% CI 7.438–79.476, P<0.0001) and use or not of CRTS (OR 0.116, 95% CI 0.035–0.382, P<0.0001) were independently and significantly associated with CRM+.Conclusion:A positive CRM was a better predictor of DFS and OS than standard pTNM stage.

Comparative study of endoluminal ultrasonography and magnetic resonance imaging in preoperative staging of rectal carcinoma

Objective To comparative study of endoluminal ultrasonography (EUS) and magnetic resonance imaging (MRI) in reoperative staging of rectal carcinoma.Methods MRI and EUS was performed prior to surgery in 58 patients with rectal carcinoma to assess its value in staging the tumor.Results The accuracy of MRI for T staging and N staging were 76.4％ and 63.9％.The accuracy of EUS for T staging and N staging were 81.8％ and 65.5％.Conclusion EUS is superior to MRI in judgment for early tumors infiltrate depth.But both have certain limitations in detection of N staging. Key words: Rectal neoplasms; Preoperative staging; Endoluminal ultrasound; Magnetic resonance imaging

Prognostic significance of total disease length in esophageal cancer

This study tested the hypothesis that endoluminal ultrasound (EUS) defined total length of disease (including both the primary tumor and the position and number of proximal and distal lymph nodes-ELoD) and the associated EUS lymph node metastasis count (ELNMC) are better predictors of outcome than endoscopic esophageal cancer (OC) length and radiological tumor node metastasis stage in patients who undergo potentially curative treatment with surgery or definitive chemoradiotherapy (dCRT). A total of 645 consecutive patients diagnosed with OC and managed by a multidisciplinary team were staged by CT and EUS. The primary outcome measure was survival from date of diagnosis. A total of 323 patients received surgery (208 neoadjuvant chemotherapy), and 322 who were deemed unsuitable for surgery received dCRT. Univariable analysis revealed that survival was related to EUS T (p < 0.0001), N (p < 0.0001), EUS primary tumor length (p = 0.037), ELoD (p = 0.011), ELNMC (p < 0.0001), and treatment type (p = 0.001). Multivariable analysis revealed two factors: ELoD (hazard ratio (HR), 0.961; 95 % confidence interval (CI), 0.925-0.998; p = 0.041) and ELNMC (HR, 1.08; 95 % CI, 1.015-1.15; p = 0.016) were independently associated with survival. ELoD and ELNMC should become part of routine OC radiological staging to optimize stage-directed therapeutic outcomes.

Sa1435 Sonographic Antomy of the Gastroesohageal Junction High Pressure Zone (GEJHPZ) Using Endoluminal Ultrasound, Manometry and High Resolution CT Scan

ents of the HPZ. From prior anatomic studies using simultaneous high resolution manometry and high frequency ultrasound with pharmacologic manipulation, these HPZ components represent a proximal lower esophageal circular muscle sphincter (LEC), a mid crural diaphragm (CD) and a distal gastric sling and clasp muscle fiber complex. The average pressure in each of these components was 24.7+/10.7mmHg in the LEC, 33.2+/-17.2mmHg in the crural diaphragm and 15.83+/-8.03 in the clasp sling muscle fiber complex. The width of the LEC, crural diaphragm and gastric sling clasp fiber complex was 1.01 +/0.25cm, 1.29 +/0.37cm and 0.76 +/0.3 cm respectively. The total length of the high-pressure zone was 4.08 +/0.61 cm. The distance between the peak pressure within the gastric sling and clasp muscle fiber complex and the crural diaphragm was 1.7 +/0.53cm and the distance between the crural diaphragm and the LEC was 1.4 +/-0.48. CONCLUSIONUsing high spatial resolution manometry within the high-pressure zone of the gastroesophageal junction, it is possible to resolve the high-pressure zone into 3 distinct and separate components. These components represent the gastric sling and clasp fiber muscle complex in the proximal stomach, the crural diaphragm measured in the distal esophagus and the LEC muscle proximal to the CD. The average pressure, width and distance between these components were measured.

New Combined Approach in Metallic Ureteral Stenting to Avoid Urothelial Hyperplasia: Study in Swine Model

We assessed the therapeutic value of a new treatment option for ureteral strictures that may avoid urothelial hyperplasia, which is the main cause of metallic stent failure. We used 24 pigs in this study. An experimental model of ureteral stricture was induced in all animals. Obstruction was confirmed by ultrasound and retrograde ureteropyelogram 6 weeks after model creation. The pigs were then randomly allocated to 2 experimental groups. Therapy involved placement of a 6 × 30 mm metallic ureteral covered stent in the ureteral stricture in group 1 and subsequent endoureterotomy at the ureteral segments adjacent to the 2 ends of the stent in group 2. A double pigtail stent was then deployed for 3 weeks. Completion studies 6 months after therapy included retrograde ureteropyelogram, endoluminal ultrasound and ureteroscopy to assess urothelial hyperplasia formation. At the end of the study evidence of urothelial hyperplasia was seen in 50% of the pigs in group 1 and in 29% in group 2. Four and 2 cases of cranial stent migration in groups 1 and 2, respectively, were seen at 6 months. Hyperplasia and renal involvement were statistically significantly different between the groups with more damage in group 1 than in group 2. Hyperplasia was markedly reduced when ureteral peristalsis was inhibited by endoureterotomy at the area of interaction between the stent and the ureter.

Epidemiology, Surgical Management and Early Postoperative Outcome in a Cohort of Gastric Cancer Patients of a Tertiary Referral Center in Relation to Multi-Center Quality Assurance Studies

The aim of the study was to analyze epidemiologic parameters, treatment-related data and prognostic factors in the management of gastric cancer patients of a university surgical center under conditions of routine clinical care before the onset of the era of multimodal therapies. By analyzing our data in relation with multi-center quality assurance trials [German Gastric Cancer Study - GGCS (1992) and East German Gastric Cancer Study - EGGCS (2004)] we aimed at providing an instrument of internal quality control at our institution as well as a base for comparison with future analyses taking into account the implementation of evolving (multimodal) therapies and their influence on treatment results. Retrospective analysis of prospectively gathered data of gastric cancer patients treated at a single institution during a defined 10-year time period with multivariate analysis of risk factors for early postoperative outcome. From 04/01/1993 through 03/31/2003, a total of 328 gastric cancer patients were treated. In comparison with the EGGCS cohort there was a larger proportion of patients with locally advanced and proximally located tumors. 272 patients (82.9%) underwent surgery with curative intent; in 88.4% of these an R0 resection was achieved (EGGCS/GGCS: 82.5%/71.5%). 68.2% of patients underwent preoperative endoluminal ultrasound (EUS) (EGGCS: 27.4%); the proportion of patients undergoing EUS increased over the study period. Diagnostic accuracy of EUS for T stage was 50.6% (EGGCS: 42.6%). 77.2% of operated patients with curative intent underwent gastrectomy (EGGCS/GGCS: 79.8%/71.1%). Anastomotic leaks at the esophagojejunostomy occurred slightly more frequently (8.8%) than in the EGGCS (5.9%) and GGCS (7.2%); however, postoperative morbidity (36.1%) and early postoperative mortality (5.3%) were not increased compared to the multi-center quality assurance study results (EGGCS morbidity, 45%); EGGCS/GGCS mortality, 8%/8.9%). D2 lymphadenectomy was performed in 72.6% of cases (EGGCS: 70.9%). Multivariate analysis revealed splenectomy as an independent risk factor for postoperative morbidity and ASA status 3 or 4 as an independent risk factor for early postoperative mortality. The rate of splenectomies performed during gastric cancer surgery decreased substantially during the study period. Preoperative diagnostics were able to accurately predict resectability in almost 90% of patients which is substantially more than the corresponding results of both the EGGCS and the GGCS. In the future, more wide-spread use of EUS will play an increasing role as stage-dependent differentiation of therapeutic concepts gains acceptance. However, diagnostic accuracy of EUS needs to be improved. Our early postoperative outcome data demonstrate that the quality standard of gastric cancer care established by the EGGCS is being fulfilled at our institution in spite of distinct characteristics placing our patients at higher surgical risk. Besides being a valuable instrument of internal quality control, our study provides a good base for comparison with ongoing analyses on future developments in gastric cancer therapy.

Prognostic significance of total disease length in oesophageal cancer

Background This study tested the hypothesis that endoluminal ultrasound (EUS) defined total length of disease (including both the primary tumor and the position and number of proximal and distal lymph nodes-ELoD) and the associated EUS lymph node metastasis count (ELNMC) are better predictors of outcome than endoscopic esophageal cancer (OC) length and radiological tumor node metastasis stage in patients who undergo potentially curative treatment with surgery or definitive chemoradiotherapy (dCRT).

Staging Strategies for Lung Cancer

LUNG CANCER HAS BECOME PERHAPS THE MOST IMPORtant cancer in the United States. The incidence has continued to increase, and lung cancer is now the leading cause of cancer death. However, most patients with lung cancer have advanced-stage disease when they first present and are not amenable to curative treatment. For the remainder, a careful search for metastatic or locally invasive tumors must be made prior to potentially curative lung resection. The lymph node drainage system for the lungs lies primarily in the mediastinum, and because it is a compact space enclosed in a rigid, bony cage, finding small lymph nodes that contain cancer is challenging. Computed tomographic (CT) evaluation of the chest reliably identifies and characterizes lung tumors but is less useful for evaluating the mediastinum for malignant disease. Mediastinal evaluation by CT is only 51% sensitive (95% confidence interval [CI], 47%-54%) and 85% specific (95% CI, 84%-88%) for establishing the diagnosis of lymph node disease in lung cancer. Consequently, mediastinoscopy is a required intermediary step between an otherwise negative metastatic evaluation for lung cancer and definitive pulmonary resection. Although complications are infrequent, mediastinoscopy is an operative procedure requiring general anesthesia and can substantially add to the overall morbidity and cost of lung cancer treatment. Positron emission tomographic (PET) scanning with the glucose analog fluorodeoxyglucose offered great promise for imaging tumors. Because cancers have higher-thannormal glucose uptake coupled with lower phosphorylation rates, fluorodeoxyglucose preferentially accumulates in malignant cells. Early studies showed great promise for this noninvasive radionucleide scanning technique to identify malignant cells too small to detect by CT. Nevertheless, inflammatory nodes resulting in false-positive results and lymph nodes too small for the resolution of current PET scanners result in a disappointingly low sensitivity of 74% (95% CI, 69%-79%) and specificity of 85% (95% CI, 82%-88%). Current clinical practice guidelines recommend that patients with lung cancer undergo CT scanning with the intent of identifying lymph node metastases and, if this imaging evaluation is unrevealing, that they next undergo PET scanning. With this strategy, some patients will still have metastatic disease in the mediastinum after noninvasive imaging. Currently, these patients undergo mediastinoscopy prior to thoracotomy in an effort to reduce the rate of unnecessary chest explorations that are potentially aborted because of previously unrecognized unresectable or metastatic lung cancer. In recent years, advances in endoluminal ultrasound (EUS) technologies facilitated high-resolution imaging of structures adjacent to the esophagus and bronchus. These devices enable biopsy of suspicious mediastinal lesions with the promise of replacing or eliminating PET imaging and mediastinoscopy in the evaluation of patients with lung cancer. Indeed, the combination of EUS and endobronchial ultrasound (EBUS) with fine-needle aspiration in nonrandomized trials demonstrated a 93% sensitivity (95% CI, 81%-99%) and 97% specificity (95% CI, 91%-99%) for establishing the presence of mediastinal disease in lung cancer patients. These impressive results suggest that the combination of EUS and EBUS could replace mediastinoscopy as well as avoid thoracotomies that proved unnecessary because of the incidental finding of advanced-stage disease. In this issue of JAMA, Annema and colleagues report the results of a randomized trial comparing mediastinoscopy and endosonography for mediastinal nodal staging of lung cancer. This study highlights several important issues regarding the importance of properly staging lung cancer preoperatively to avoid surgical intervention in a group of patients who have no proven benefit from resection and in fact would have a reduction in their quality of life from an unnecessary thoracotomy. This randomized study compares the use of endoscopic ultrasound via either esophagoscopy, bronchoscopy, or both, followed by surgical staging if no nodal metastases were found, to the past gold standard of surgical staging either by mediastinoscopy or parasternal biopsy. This welldesigned study attempts to answer the question of how this