4D PC MR imaging allows for a detailed assessment of CSF flow dynamics helping to distinguish physiological from complex pathological flow patterns at the craniocervical junction and the cervical spine.

CSF hydrodynamics are thought to be altered in craniospinal disorders such as Chiari I malformation. MRI scanning techniques and protocols can be used to quantify CSF flow alterations in disease states. The provided in vitro models can be used to test the reliability of these protocols across MRI scanner manufacturers and machines.

Purpose Lymphoceles often occur within several weeks or even months after surgery. Mostly asymptomatic and therefore undiagnosed, they may be self-healing without any treatment. A small percentage of postoperative lymphoceles are symptomatic with significant pain, infection, or compression of vital structures, thus requiring intervention. Many different treatment options are described in the literature, like drainage with or without sclerotherapy, embolization of lymph vessels, and surgical approaches with laparoscopy or laparotomy. Inspired by reports stating that postoperative suction drainage can prevent the formation of lymphoceles, we developed a simple protocol for vacuum-assisted drainage of symptomatic lymphoceles, which proved to be successful and which we would therefore like to present. Materials and Method Between 2008 and 2020, 35 patients with symptomatic postoperative lymphoceles were treated with vacuum-assisted suction drainage (in total 39 lymphoceles). The surgery that caused lymphocele formation had been performed between 8 and 572 days before. All lymphoceles were diagnosed based on biochemical and cytologic findings in aspirated fluid. The clinical and imaging data were collected and retrospectively analyzed. Results In total, 43 suction drainage catheters were inserted under CT guidance. The technical success rate was 100 %. One patient died of severe preexisting pulmonary embolism, sepsis, and poor conditions (non-procedure-related death). In 94.8 % of symptomatic lymphoceles, healing and total disappearance could be achieved. 4 lymphoceles had a relapse or dislocation of the drainage catheter and needed a second drainage procedure. Two lymphoceles needed further surgery. The complication rate of the procedure was 4.6 % (2/43, minor complications). The median indwelling time of a suction drainage catheter was 8–9 days (range: 1–30 days). Conclusion The positive effects of negative pressure therapy in local wound therapy have been investigated for a long time. These positive effects also seem to have an impact on suction drainage of symptomatic lymphoceles with a high cure rate. Key Points:  Citation Format

Background The Nimbus stent-retriever (NSR) was developed for mechanical thrombectomy of wall-adherent thrombi in cerebral arteries. It features a novel geometry with a proximal spiral section and a distal barrel section. The new device is designed to retrieve tough clots with a micro-clamping technique. In the first case series reporting on the NSR, we share our initial experience about the first 12 treated cases. Methods In total, 12 patients (5 men, 7 women; mean age 78 years) with occlusion of the internal carotid artery or the middle cerebral artery (M1 or M2 segment) were treated with the NSR, 11 after unsuccessful recanalization attempts with conventional stent-retrievers or aspiration thrombectomy. Results Retrieving maneuvers with the NSR recovered a thrombus in 7 patients (58%), of which 6 resulted in vessel recanalization mTICI ≥ 2b. Successful recanalization improved the mTICI score by a median of 3 points. In 5 of 7 cases, this required only one thrombectomy maneuver. In 5 cases, no improvement of recanalization could be achieved with the NSR (1–3 attempts). No NSR-related complications occurred in this case series. Conclusions In our initial experience, the NSR appeared to be a safe and effective second-line stent-retriever after unsuccessful MT with conventional stent-retrievers or aspiration thrombectomy allowing for mTICI ≥ 2b rescue thrombectomy in ab 50% of cases. No NSR associated complications occurred in our case series.