Background/Objectives: Ultrasound-assisted catheter-directed thrombolysis (USAT) and mechanical thrombectomy (MT) are increasingly used for intermediate-high-risk pulmonary embolism (PE), but real-world comparisons are scarce. We compare 30-day all-cause, cardiovascular, non-cardiovascular, PE-related, and major bleeding events between intermediate-high-risk patients with acute PE treated with USAT or MT. Methods: We analyzed 286 patients with acute intermediate-high-risk PE enrolled in the multicenter USAT IH-PE registry (March 2019–October 2025). Patients underwent USAT (EKOS™, Boston Scientific, Marlborough, MA, USA) or MT (FlowTriever, Inari Medical, Irvine, CA, USA or Indigo, Penumbra, Inc., Alameda, CA, USA) during index hospitalization. Primary endpoints were 30-day all-cause, cardiovascular, and PE-related mortality. Propensity score matching (1:1) balanced baseline characteristics. Kaplan–Meier analyses with log-rank testing assessed time-to-event outcomes. Results: After matching (69 patients per group), baseline clinical and hemodynamic variables were well balanced. Both USAT and MT significantly improved RV/LV ratio, tricuspid annular plane systolic excursion (TAPSE), and PASP (all p < 0.001). Thirty-day all-cause mortality was similar between USAT and MT (13.0% vs. 11.5%; p = 0.78), with no differences in cardiovascular or PE-related mortality (8.6% vs. 1.4%, p = 0.58 and 5.7% vs. 1.4%, p = 0.17, respectively). Major bleeding was infrequent and observed only in the USAT group (4.3%). Conclusions: In this real-world multicenter cohort, USAT and MT showed comparable short-term mortality, safety, and echocardiographic recovery, supporting individualized catheter-based reperfusion strategies for intermediate-high-risk PE.

Disappearing liver metastases (DLMs) remain a challenging problem in the management of colorectal liver metastases (CRLMs). Although modern systemic therapy may produce complete radiological responses, radiological disappearance does not reliably indicate complete pathological response. Conversely, mandatory treatment of every original metastatic site may cause unnecessary parenchymal sacrifice when a lesion is no longer identifiable on hepatobiliary contrast-enhanced magnetic resonance imaging or intraoperative ultrasonography. Current strategies—including treatment of the presumed site, selective pre-treatment fiducial marking where feasible and considered appropriate, and structured surveillance—therefore involve important trade-offs. We propose a hypothesis-generating, lesion-specific strategy for a narrowly selected subgroup: thermal ablation before systemic therapy of one or a few small CRLM, preferably no larger than 2 cm, considered at higher anticipated risk of post-treatment loss of localization. Selection should distinguish the probability of radiological disappearance from its clinical consequences. Candidate lesions should be clearly and unambiguously identifiable on high-quality baseline imaging, safely accessible for ablation with a margin greater than 5 mm and ideally approximately 10 mm, and located outside any planned resection field, particularly when their depth or anatomical position would make empirical treatment difficult after disappearance. Recent randomized evidence supports thermal ablation as definitive local therapy for appropriately selected small CRLM but does not validate the proposed pre-systemic treatment sequence. This approach should not delay urgently required systemic therapy, compromise biological selection, or be used indiscriminately in high-volume, rapidly progressive, uncontrolled extrahepatic, or technically unsuitable disease. It is also generally unnecessary when the lesion is encompassed by a planned resection or total hepatectomy within a liver transplantation pathway. Upfront ablation may secure local control while the target remains visible, preserve liver parenchyma, and avoid premature interruption of systemic therapy or acceleration of surgery solely because a responding lesion is becoming radiologically occult. However, it may cause overtreatment and procedural morbidity and remains unsupported by prospective comparative evidence. A multicentre feasibility study, followed by prospective comparison with contemporary standard sequencing and, where feasible and considered appropriate, fiducial-based localization, is required to evaluate this strategy.