Lumbar plexus block surface landmarks as assessed by computed axial tomography in adult patients with scoliosis: a case series.

BACKGROUND AND OBJECTIVES: Lumbar plexus (LP) block is a common and useful regional anesthesia technique. Surface landmarks used to identify the LP in patients with healthy spines have been previously described, with the distance from the spinous process (SP) to the skin overlying the LP being approximately two-thirds the distance from the SP to the posterior superior iliac spine (PSIS) (SP-LP:SP-PSIS ratio). In scoliotic patients, rotation of the central neuraxis may make these surface landmarks unreliable, possibly leading to an increased block failure rate and an increased incidence of complications. The objective of the present study was to describe these surface landmarks of the LP in patients with scoliosis. METHODS: We selected 47 patients with known thoracolumbar scoliotic disease from our institution's radiology archives. We measured bony landmark geometry, Cobb angle, and the LP location and depth. Additionally, we calculated the SP-LP:SP-PSIS ratio for both the concave and convex sides. RESULTS: In scoliotic patients (31 females and 16 males), the median (range) Cobb angle was 23 (8-54) degrees. The LP depth was 7.5 (5.7-10.7) cm on the concave side of the scoliotic spine and 7.6 (5.4-10.8) cm on the convex side, while the distance from the SP-LP was 3.4 (1.9-4.7) cm on the concave side and 3.7 (2.4-5.1) cm on the convex side. The SP-LP:SP-PSIS ratio was 0.61 (0.20-0.97) and 0.65 (0.45-0.98) on the concave and convex sides, respectively. None of these distances were significantly different between sides. CONCLUSIONS: In patients with scoliotic disease of the spine, there is wide variability in the bony surface landmarks. The location of the LP is generally more medial than expected when compared with both modified and traditional landmarks. A review of the imaging studies and the pre-procedural ultrasound assessment of the anatomy should be considered prior to needle puncture.

Extrahepatic portal biliopathy: proposed etiology on the basis of anatomic and clinical features.

PURPOSE: To compare the anatomic and clinical features in patients with chronic portal vein thrombosis (PVT) to determine why some patients develop portal biliopathy (PB) while most do not and propose an etiology for PB. MATERIALS AND METHODS: This project satisfied HIPAA regulations and received institutional review board approval for a retrospective review without the need for consent. From 100 patients with PVT, 60 were extracted who had chronic, nonmalignant PVT, after exclusion of those with sclerosing cholangitis, liver transplants, choledocholithiasis, or portosystemic shunts. Clinical and imaging data from 19 patients with biliary dilatation (PB group) were compared with data from 41 patients without biliary dilatation (no-PB group). Statistical analysis was performed with the Fisher exact test for categorical variables or the Wilcoxon rank-sum test for numerical and ordered categorical variables. P values of .05 or less were considered to indicate a significant difference. RESULTS: The etiology of PVT differed between the groups (P < .001); cirrhosis was infrequently seen in the PB group (two of 19, 11%) but was common in the no-PB group (31 of 41, 76%). Only two of 33 (6%) patients with cirrhosis and PVT had PB. Extension of PVT into the mesenteric veins was significantly more common in the PB group (18 of 19, 95%) than in the no-PB group (one of 41, 2%) (P < .001). Compared with the no-PB group, patients in the PB group had more acute angulation of the bile duct (median, 110° vs 128°; P = .008), less frequent gastroesophageal varices (three of 19 [16%] vs 20 of 41 [49%], P = .021), and a smaller mean coronary vein diameter (median, 5 vs 6 mm; P = .014). CONCLUSION: Noncirrhotic patients with hypercoagulable states tend to develop PB when PVT extends to the splenomesenteric veins. A possible etiology is the formation of specific peribiliary venous pathways responsible for bile duct compression and tethering.

Use of rituximab for periocular and intraocular mucosa-associated lymphoid tissue lymphoma.

The clinical efficacy of rituximab therapy in systemic mucosa-associated lymphoid tissue (MALT) lymphoma with both periocular and intraocular involvement is described. Ophthalmic examination and radiologic imaging demonstrated tumor with bilateral periorbital, lacrimal, and subconjunctival infiltration, a pseudohypopyon in one eye, and extensive systemic lymph node involvement. Lymph node biopsy confirmed the pathologic findings of a low-grade MALT lymphoma. The patient had a complete remission within 3 months of starting rituximab therapy. A recurrence 6 months later remitted with a second round of rituximab therapy and the patient remained tumor-free at 1 year.

Cyclops lesions that occur in the absence of prior anterior ligament reconstruction.

Loss of full extension after anterior cruciate ligament (ACL) reconstruction, with development of an audible and palpable "clunk" with terminal extension was first described by Jackson and Schaefer as "cyclops syndrome." This syndrome, which is the result of a fibrous nodule (termed a cyclops nodule), has recently been described in patients who have sustained ACL injury but have not undergone reconstructive surgery. From 2001 to 2006, the authors identified 10 patients (five women and five men, ages 27-76 years) with cyclops nodules seen at magnetic resonance (MR) imaging. All patients had a history of trauma but no history of ACL reconstruction. The cyclops lesions had a mean size of 16 x 12 x 11 mm, with 90% of them located just anterior to the distal ACL. MR imaging showed a well-defined, somewhat heterogeneous soft-tissue nodule with a signal intensity typically similar to that of skeletal muscle. The authors suspect that the cause of cyclops lesions that occur in the absence of ACL reconstruction is similar to that suggested in the classic postoperative patient. Cyclops syndrome should be suspected in any patient in whom an ACL nodule is identified at MR imaging, and similarly a cyclops nodule should be considered as a possible cause of loss of extension in any patient who has sustained ACL injury. Movies available at http://radiographics.rsnajnls.org/cgi/content/full/e26/DC1.