Effectiveness of Epiduroscopy for Patients with Failed Back Surgery Syndrome: A Systematic Review and Meta-analysis.

INTRODUCTION: Low-back or leg pain in patients suffering from failed back surgery syndrome (FBSS) is often severe, having a major impact on functionality and quality of life. Despite conservative and surgical treatments, pain can be persistent. An alternative treatment option is epiduroscopy, a minimally invasive procedure based on mechanical adhesiolysis of epidural fibrosis. As epidural fibrosis is speculated to be a major contributor in the pathophysiologic process of FBSS, this review evaluates the effectiveness of epiduroscopy in FBSS patients. METHODS AND MATERIALS: A systematic literature search was performed in PubMed, Embase, and Cochrane databases. Critical appraisal was performed using validated tools. Meta-analysis was performed using generic inverse variance analysis. RESULTS: From the 286 identified articles, nine studies were included. The visual analogue scale (VAS) average was 7.6 at baseline, 4.5 at 6, and 4.3 at 12 months. The Oswestry Disability Index (ODI) average was 61.7% at baseline, 42.8% at 6, and 46.9% at 12 months. An average of 49% of patients experienced significant pain relief at 6 and 37% at 12 months. Meta-analysis showed a pooled VAS mean difference of 3.4 (2.6 to 4.1; 95% confidence interval [CI]) and 2.8 (1.6 to 4.0; 95% CI) and pooled ODI mean difference of 19.4% (12.5 to 26.4%; 95% CI) and 19.8% (13.8 to 25.9%; 95% CI) at 6 and 12 months, respectively. CONCLUSION: Current literature demonstrates a clinically relevant reduction in pain and disability scores at 6 to 12 months after mechanical adhesiolysis in FBSS patients. The quality of evidence is moderate, and the level of recommendation is weak. Practitioners should consider the benefits of epiduroscopy after weighing the risks for individual patients with FBSS.

Prognostic value of the area and density of lymphatic vessels in cutaneous squamous cell carcinoma.

BACKGROUND AND OBJECTIVES: Cutaneous squamous cell carcinoma (SCC) is known for its capacity to metastasize via lymphatic vessels. In recent studies, the level of lymphangiogenesis has been reported as a potential prognostic factor for several skin tumors. The aim of this study was to quantify lymphangiogenesis in SCC using either computer-assisted image analysis or the Chalkley count technique. Vascular parameters were evaluated and compared with respect to their predictive power for tumor metastasis. PATIENT AND METHODS: In this case-control study, clinical and histological data of 15 metastatic and 15 nonmetastatic SCC patients were retrospectively analyzed. SCC samples were immunostained for the lymphatic endothelial marker D2-40 and the panvascular marker CD31, and analyzed using computer-assisted morphometric image analyses within hot spots as well as the digitalized Chalkley counting method. RESULTS: Lymphatic vessel density, relative lymphatic vessel area, and lymphatic Chalkley count were significantly elevated in metastatic SCC. Tumor thickness was significantly higher in metastatic SCC, and had the highest predictive power for metastatic disease. Tumor thickness was a significant predictor of lymphangiogenic parameters. CONCLUSIONS: Lymphangiogenesis is elevated in metastatic SCC but its extent is influenced by tumor thickness. Tumor thickness remains the most reliable predictive factor for metastatic disease.

Prognostischer Wert der Fläche und Dichte von Lymphgefäßen bei kutanem Plattenepithelkarzinom.

HINTERGRUND UND ZIELE: Kutane Plattenepithelkarzinome (SCC) sind bekannt für ihre Fähigkeit, über Lymphgefäße zu metastasieren. In neueren Studien wird das Ausmaß der Lymphangiogenese als möglicher prognostischer Faktor bei einigen Hauttumoren genannt. Ziel dieser Studie war die Quantifizierung der Lymphangiogenese bei SCC entweder durch computergestützte Bildanalyse oder mithilfe der Zählmethode nach Chalkley. Gefäßparameter wurden im Hinblick auf ihre Vorhersagekraft für die Bildung von Tumormetastasen beurteilt und verglichen. PATIENTEN UND METHODEN: In dieser Fallkontrollstudie wurden die klinischen und histologischen Daten von jeweils 15 SCC-Patienten mit bzw. ohne Metastasen retrospektiv analysiert. In den SCC-Proben wurde der für das Lymphendothel spezifische Marker D2-40 und der pan-vaskuläre Marker CD31 immunhistochemisch angefärbt und durch computergestützte morphometrische Bildanalyse in Hotspots sowie mithilfe der digitalisierten Zählmethode nach Chalkley analysiert. ERGEBNISSE: Die Dichte von Lymphgefäßen, die relative Lymphgefäßfläche und die mit der Chalkley-Methode ermittelte Zahl an Lymphgefäßen (Chalkley-Count) waren bei metastasierten SCC signifikant erhöht. Die Tumordicke war bei metastasierten SCC signifikant höher und besaß die höchste Vorhersagekraft für eine Metastasierung. Die Tumordicke war ein signifikanter Prädiktor für Lymphangiogeneseparameter. SCHLUSSFOLGERUNGEN: Die Lymphangiogenese ist bei metastasierten SCC erhöht, doch ihr Ausmaß wird von der Tumordicke beeinflusst. Die Tumordicke bildet weiterhin den zuverlässigsten prädiktiven Faktor für die Metastasierung.

Modeling, Production, and Testing of an Echogenic Needle for Ultrasound-Guided Nerve Blocks.

We have designed, produced, and tested an echogenic needle based on a sawtooth pattern where the height of the tooth was 1.25 times the wavelength of the ultrasound transducer. A numeric solution to the time-independent wave equation (Helmholtz equation) was used to create a model of backscattering from a needle. A 21-gauge stainless steel prototype was manufactured and tested in a water bath. Backscattering from the needle was compared to theoretical predications from our model. Based on these results, an 18-gauge prototype needle was fabricated from stainless steel and tested in a pig cadaver. This needle was compared to a commercial 18-gauge echogenic needle (Pajunk Medical Systems, Tucker, GA) by measuring the brightness of the needle relative to the background of sonograms of a needle in a pig cadaver. The backscattering from the 21-gauge prototype needle reproduced the qualitative predictions of our model. At 30° and 45° of insonation, our prototype performed equivalently to the Pajunk needle. At 60°, our prototype was significantly brighter than the Pajunk needle (P = .017). In conclusion, we chose a model for the design of an echogenic needle and modeled it on the basis of a solution to the Helmholtz equation. A prototype needle was tested in a water bath and compared to the model prediction. After verification of our model, we designed an 18-gauge needle, which performed better than an existing echogenic needle (Pajunk) at 60° of insonation. Our needle will require further testing in human trials.

Different Approaches to Ultrasound-guided Thoracic Paravertebral Block: An Illustrated Review.

Given the fast development and increasing clinical relevance of ultrasound guidance for thoracic paravertebral blockade, this review article strives (1) to provide comprehensive information on thoracic paravertebral space anatomy, tailored to the needs of a regional anesthesia practitioner, (2) to interpret ultrasound images of the thoracic paravertebral space using cross-sectional anatomical images that are matched in location and plane, and (3) to briefly describe and discuss different ultrasound-guided approaches to thoracic paravertebral blockade. To illustrate the pertinent anatomy, high-resolution photographs of anatomical cross-sections are used. By using voxel anatomy, it is possible to visualize the needle pathway of different approaches in the same human specimen. This offers a unique presentation of this complex anatomical region and is inherently more realistic than anatomical drawings.

Intraneural or extraneural: diagnostic accuracy of ultrasound assessment for localizing low-volume injection.

BACKGROUND AND OBJECTIVES: When one is performing ultrasound-guided peripheral nerve blocks, it is common to inject a small amount of fluid to confirm correct placement of the needle tip. If an intraneural needle tip position is detected, the needle can then be repositioned to prevent injection of a large amount of local anesthetic into the nerve. However, it is unknown if anesthesiologists can accurately discriminate intraneural and extraneural injection of small volumes. Therefore, this study was conducted to determine the diagnostic accuracy of ultrasound assessment using a criterion standard and to compare experts and novices in ultrasound-guided regional anesthesia. METHODS: A total of 32 ultrasound-guided infragluteal sciatic nerve blocks were performed on 21 cadaver legs. The injections were targeted to be intraneural (n = 18) or extraneural (n = 14), and 0.5 mL of methylene blue 1% was injected. Cryosections of the nerve and surrounding tissue were assessed by a blinded investigator as "extraneural" or "intraneural." Ultrasound video clips of the injections were reviewed by 10 blinded observers (5 experts, 5 novices) independently who scored each injection as either "intraneural," "extraneural," or "undetermined." RESULTS: The mean sensitivity of experts and novices was measured to be 0.84 (0.80-0.88) and 0.65 (0.60-0.71), respectively (P = 0.006), whereas mean specificity was 0.97 (0.94-0.98) and 0.98 (0.96-0.99) (P = 0.53). CONCLUSIONS: Discrimination of intraneural or extraneural needle tip position based on an injection of 0.5mL is possible, but even experts missed 1 of 6 intraneural injections. In novices, the sensitivity of assessment was significantly lower, highlighting the need for focused education.