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Gregor Durner, Yigit Özpeynirci, Bernd Schmitz, Christian Rainer Wirtz, Ralph König and Andrej Pala

Recently, treatment of cerebral aneurysms with the Woven EndoBridge (WEB) device has become an established endovascular strategy. However, over time, neurosurgeons and neuroradiologists will be confronted with the challenge of how to treat aneurysm recanalization. The authors report the case of a 49-year-old woman who underwent re-treatment with clipping after the recanalization of a 4 × 3–mm anterior communicating artery aneurysm that had previously been treated using a 4 × 3 WEB device. In contrast to the authors’ prior experiences with clipping of previously coiled aneurysms, the WEB device was found to have a responsive softness during clip placement, and the aneurysm was more maneuverable. Moreover, evaluation with indocyanine green angiography was easy to perform because of the transparent mesh of the WEB device. No profound scarring or WEB protrusion was noted during surgery, making the procedure easier and less dangerous with regard to additional complications. The authors suggest that re-treatment via clipping should be considered in select cases of aneurysm recurrence after treatment with an intraaneurysmal flow diverter.

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Andrej Pala, Fadi Awad, Michael Braun, Michal Hlavac, Arthur Wunderlich, Bernd Schmitz, Christian Rainer Wirtz and Jan Coburger

OBJECTIVE

The gold standard for evaluation of ventriculoperitoneal (VP) shunt position, dislocation, or disconnection is conventional radiography. Yet, assessment with this modality can be challenging because of low image quality and can result in repetitive radiation exposure with high fluctuation in the radiation dose. Recently, CT-based radiation doses have been significantly reduced by using low-dose protocols. Thus, whole-body low-dose CT (LDCT) has become applicable for routine use in VP shunt evaluation. The authors here compared image quality and approximate radiation dose between radiography and LDCT in patients with implanted VP shunt systems.

METHODS

Ventriculoperitoneal shunt systems have been investigated with LDCT scanning at the authors’ department since 2015. A consecutive series of 57 patients (70 investigations) treated between 2015 and 2016 was retrospectively assessed. A historical patient cohort that had been evaluated with radiography was compared with the LDCT patients in terms of radiation dose and image quality. Three independent observers evaluated projection of the valve pressure level and correct intraperitoneal position, as well as complete shunt projection, using a Likert-type scale of 1–5, where 1 indicated “not assessable” and 5 meant “assessable with high accuracy.” Descriptive statistics and the Mann-Whitney U-test were used for analysis.

RESULTS

Twenty-seven radiographs (38.6%) and 43 LDCT scans (61.4%) were analyzed. The median dose-length product (DLP) of the LDCT scans was 100 mGy·cm (range 59.9–183 mGy·cm). The median total dose-area product (DAP) of the radiographic images was 3177 mGy·cm2 (range 641–13,833 mGy·cm2). The estimated effective dose (EED) was significantly lower with the LDCT scan (p < 0.001). The median EED was 4.93 and 1.90 mSv for radiographs and LDCT, respectively. Significantly better identification of the abdominal position of the distal shunt catheter was achieved with LDCT (p < 0.001). Simultaneously, significantly improved visualization of the entire shunt system was realized with this technique (p < 0.001). On the contrary, identification of the valve settings was significantly worse with LDCT (p < 0.001).

CONCLUSIONS

Whole-body LDCT scanning allows good visualization of the distal catheter after VP shunt placement. Despite the fact that only a rough estimation of effective doses is possible in a direct comparison of LDCT and radiography, the data showed that shunt assessment via LDCT does not lead to greater radiation exposure. Thus, especially in difficult anatomical conditions, as in patients who have undergone multiple intraabdominal surgeries, have a high BMI, or are immobile, the use of LDCT shunt evaluation has high clinical value. Further data are needed to determine the value of LDCT for the evaluation of complications or radiation dose in pediatric patients.

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Andrej Paľa, Julia Schick, Moritz Klein, Benjamin Mayer, Bernd Schmitz, Christian Rainer Wirtz, Ralph König and Thomas Kapapa

OBJECTIVE

Delayed cerebral ischemia (DCI) is a major factor contributing to the inferior outcome of patients with spontaneous subarachnoid hemorrhage (SAH). Nimodipine and induced hypertension using vasopressors are an integral part of standard therapy. Consequences of the opposite effect of nimodipine and vasopressors on blood pressure on patient outcome remain unclear. The authors report the detailed general characteristics and influence of nimodipine and vasopressors on outcome in patients with SAH.

METHODS

The authors performed a 2-center, retrospective, clinical database analysis of 732 SAH patients treated between 2008 and 2016. Demographic and clinical data such as age, sex, World Federation of Neurosurgical Societies (WFNS) grade, BMI, Fisher grade, history of arterial hypertension and smoking, aneurysm location, C-reactive protein (CRP) level, and detailed dosage of vasopressors and nimodipine during the treatment period were evaluated. Clinical outcome was analyzed using the modified Rankin Scale (mRS) 6 months after treatment. Univariate and multivariate regression analyses were performed. Additionally, mean arterial pressure (MAP), age, nimodipine, and vasopressor dose cutoff were evaluated with regard to outcome. The level of significance was set at ≤ 0.05.

RESULTS

Follow-up was assessed for 397 patients, 260 (65.5%) of whom achieved a good outcome (defined as an mRS score of 0–3). Univariate and multivariate analyses confirmed that nimodipine (p = 0.049), age (p = 0.049), and CRP level (p = 0.002) are independent predictors of good outcome. WFNS grade, Fisher score, hypertension, initial hydrocephalus, and total vasopressor dose showed significant influence on outcome in univariate analysis, and patient sex, smoking status, BMI, and MAP showed no significant association with outcome. A subgroup analysis of patients with milder initial SAH (WFNS grades I–III) revealed that initial hydrocephalus (p = 0.003) and CRP levels (p = 0.001) had significant influence on further outcome. When evaluating only patients with WFNS grade IV or V, age, CRP level (p = 0.011), vasopressor dose (p = 0.030), and nimodipine dose (p = 0.049) were independent predictors of patient outcome. Patients with an MAP < 93 mm Hg, a nimodipine cutoff dose of 241.8 mg, and cutoff total vasopressor dose of 523 mg had better outcomes.

CONCLUSIONS

According to the authors’ results, higher doses of vasopressors can safely provide a situation in which the maximum dose of nimodipine could be administered. Cutoff values of the total vasopressor dose were more than 3 times higher in patients with severe SAH (WFNS grade IV or V), while the nimodipine cutoff remained similar in patients with mild and severe SAH. Hence, it seems encouraging that a maximum nimodipine dosage can be achieved despite the need for a higher vasopressor dose in patients with SAH.