MR imaging of venous malformations: sciatic nerve infiltration patterns and involved muscle groups.

The aim of this retrospective cross-sectional study was to provide an MRI-based examination framework of venous malformations (VMs) infiltrating the sciatic nerve and determine the frequency of nerve infiltration patterns and muscle involvement in correlation to the patients' quality of life. Pelvic and lower limb MR images of 378 patients with vascular malformations were examined retrospectively. Pain levels and restriction of motion were evaluated with a questionnaire. Cross-sectional areas of affected nerves were compared at standardized anatomical landmarks. Intraneural infiltration patterns and involvement of muscles surrounding the sciatic nerve were documented. Sciatic nerve infiltration occurred in 23/299 patients (7.7%) with VM. In all cases (23/23; 100%), gluteal or hamstring muscles surrounding the nerve were affected by the VM. Infiltrated nerves were enlarged and showed signal alterations (T2-hyperintensity) compared to the unaffected side. Enlarged nerve cross-sectional areas were associated with elevated pain levels. Three nerve infiltration patterns were observed: subepineurial (12/23; 52.2%), subparaneurial (6/23; 26.1%) and combined (5/23; 21.7%) infiltration. This study provides a clinically relevant assessment for sciatic nerve infiltration patterns and muscle involvement of VMs, while suggesting that VMs in gluteal and hamstring muscles require closer investigation of the sciatic nerve by the radiologist.

Author Correction: Rectosigmoidal manifestations of venous malformations: MR imaging findings and interdisciplinary therapeutic modalities.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Rectosigmoidal manifestations of venous malformations: MR imaging findings and interdisciplinary therapeutic modalities.

The aim of this study was to identify the frequency of rectosigmoidal involvement in patients with venous malformations (VM) of the lower extremities and to demonstrate multidisciplinary therapeutic options. The medical records and magnetic resonance images (MRI) of patients with VM of the lower extremities, over a six-year period, were reviewed retrospectively in order to determine the occurrence of rectosigmoidal involvement. Vascular interventions, surgical treatments, percutaneous and hybrid (endoscopy-guided angiography) sclerotherapy and procedural complications (according to Clavien-Dindo classification) were also noted. Of the 378 patients with vascular malformation of the lower limbs, 19 patients (5%) had documented venous rectosigmoidal malformation. All of these 19 patients reported episodes of rectal bleeding, while seven patients (36.8%) also had anemia. All patients underwent endoscopy. By endoscopy, seven patients (36.8%) showed discreet changes, and 12 patients (63.2%) showed pronounced signs of submucosal VM with active (47.3%) or previous (15.7%) bleeding. Treatment was performed in all patients with pronounced findings. Six patients underwent endoscopy-guided hybrid sclerotherapy, one patient underwent endoscopic tissue removal, one patient received percutaneous sclerotherapy and one patient received a combination of transvenous embolization and hybrid sclerotherapy. Three patients required open surgery. No complications occurred after conservative treatments; however, one complication was reported after open surgery. None of the treated patients reported further bleeding and anemia at the end of the follow-up period. In this cohort, rectosigmoidal VM occurred in 5% of patients presenting with a high incidence of rectal bleeding. Percutaneous or endoscopy-guided hybrid sclerotherapy appeared to be a safe and effective alternative to surgery.

Discrepant post filter ionized calcium concentrations by common blood gas analyzers in CRRT using regional citrate anticoagulation.

INTRODUCTION: Ionized calcium (iCa) concentration is often used in critical care and measured using blood gas analyzers at the point of care. Controlling and adjusting regional citrate anticoagulation (RCA) for continuous renal replacement therapy (CRRT) involves measuring the iCa concentration in two samples: systemic with physiological iCa concentrations and post filter samples with very low iCa concentrations. However, modern blood gas analyzers are optimized for physiological iCa concentrations which might make them less suitable for measuring low iCa in blood with a high concentration of citrate. We present results of iCa measurements from six different blood gas analyzers and the impact on clinical decisions based on the recommendations of the dialysis' device manufacturer. METHOD: The iCa concentrations of systemic and post filter samples were measured using six distinct, frequently used blood gas analyzers. We obtained iCa results of 74 systemic and 84 post filter samples from patients undergoing RCA for CRRT at the University Medicine of Greifswald. RESULTS: The systemic samples showed concordant results on all analyzers with median iCa concentrations ranging from 1.07 to 1.16 mmol/L. The medians of iCa concentrations for post filter samples ranged from 0.21 to 0.50 mmol/L. Results of >70% of the post filter samples would lead to major differences in decisions regarding citrate flow depending on the instrument used. CONCLUSION: Measurements of iCa in post filter samples may give misleading information in monitoring the RCA. Recommendations of the dialysis manufacturer need to be revised. Meanwhile, little weight should be given to post filter iCa. Reference methods for low iCa in whole blood containing citrate should be established.