Infected Thrombosis Leading to Veno-Venous Extracorporeal Membrane Oxygenation Dysfunction in Chronic Thromboembolic Pulmonary Hypertension.

Nosocomial infections and thrombosis are frequent complications during extracorporeal membrane oxygenation (ECMO). Preventative measures and close monitoring for early recognition of these complications are imperative in patients supported with ECMO. We report the case of a 41 year old female on veno-venous ECMO awaiting surgical thrombectomy for chronic thromboembolic pulmonary hypertension that developed profound bacteremia leading to gross purulence and thrombosis of the membrane oxygenator. Recannulation in addition to targeted antibiotics, frequent cultures, imaging, and surgery were diagnostic and therapeutic interventions that led to ultimate resolution.

Early veno-venous extracorporeal membrane oxygenation is an effective strategy for traumatically injured patients presenting with refractory respiratory failure.

BACKGROUND: Venovenous extracorporeal membrane oxygenation (VV ECMO) is used for respiratory failure when standard therapy fails. Optimal trauma care requires patients be stable enough to undergo procedures. Early VV ECMO (EVV) to stabilize trauma patients with respiratory failure as part of resuscitation could facilitate additional care. As VV ECMO technology is portable and prehospital cannulation possible, it could also be used in austere environments. We hypothesize that EVV facilitates injury care without worsening survival. METHODS: Our single center, retrospective cohort study included all trauma patients between January 1, 2014, and August 1, 2022, who were placed on VV ECMO. Early VV was defined as cannulation ≤48 hours from arrival with subsequent operation for injuries. Data were analyzed with descriptive statistics. Parametric or nonparametric statistics were used based on the nature of the data. After testing for normality, significance was defined as a p < 0.05. Logistic regression diagnostics were performed. RESULTS: Seventy-five patients were identified and 57 (76%) underwent EVV. There was no difference in survival between the EVV and non-EVV groups (70% vs. 61%, p = 0.47). Age, race, and gender did not differ between EVV survivors and nonsurvivors. Time to cannulation (4.5 hours vs. 8 hours, p = 0.39) and injury severity scores (34 vs. 29, p = 0.74) were similar. Early VV survivors had lower lactic acid levels precannulation (3.9 mmol/L vs. 11.9 mmol/L, p < 0.001). A multivariable logistic regression analysis examining admission and precannulation laboratory and hemodynamic values demonstrated that lower precannulation lactic acid levels predicted survival (odds ratio, 1.2; 95% confidence interval, 1.02-1.5; p = 0.03), with a significant inflection point of 7.4 mmol/L corresponding to decreased survival at hospital discharge. CONCLUSION: Patients undergoing EVV did not have increased mortality compared with the overall trauma VV ECMO population. Early VV resulted in ventilatory stabilization that allowed subsequent procedural treatment of injuries. LEVEL OF EVIDENCE: Therapeutic Care/Management; Level III.

In Vivo Assessment of Ascending and Arch Aortic Compliance.

BACKGROUND: Dynamic compliance (Cd) of the adult thoracic ascending and arch aorta has had limited in vivo evaluation in patients with aortic disease. This study evaluates aortic compliance using intravascular ultrasound (IVUS) across a range of thoracic aortic diseases. METHODS: Seventy-nine patients undergoing thoracic aortic endovascular procedures had Cd measurements of the ascending aorta proximal to the origin of the brachiocephalic trunk and distal to the origin of the left common carotid artery using IVUS before endograft deployment. Cd was calculated for each segment using the following equation, Cd = ΔD/(D • ΔP) where ΔD = change in aortic diameter, D = diameter in diastole, and ΔP = pulse pressure. RESULTS: Mean Cd of the ascending aorta in all patients (18.4%/mm Hg) and aortic arch (16.5 %/100 mm Hg) did not differ significantly. Compliance was significantly lower in patients being treated for thoracic aortic aneurysm and penetrating ulcer than in patients with traumatic rupture, acute and chronic dissection (P = 0.009). Compliance was significantly higher in patients with aortic transection compared with thoracic aneurysm or penetrating ulcer (P = 0.001). Compliance decreased with age by 0.44 ± 0.06 (P = 0.001) per year in the ascending aorta and 0.41 ± 0.05 (P = 0.001) per year in the aortic arch. Compliance did not increase with diameter when adjusted for age (P = 0.65). Compliance measured in the ascending aorta in 7 patients after descending thoracic aortic endograft repair decreased to 12.6%/100 mm Hg, although not significant (P = 0.18). CONCLUSIONS: Ascending and aortic arch compliance is significantly higher than reported for peripheral vessels. Thoracic aortic compliance decreases with age and is not related to aortic diameter. The results of the present study are important when considering the development of endoprosthesis devices and long-term effects on the thoracic aorta.

Tissue loss secondary to extrinsic compression of common iliac artery from uterine leiomyoma: a case report and review of the literature.

BACKGROUND: Uterine leiomyomas are commonly reported to cause deep venous thrombosis and rarely arterial compression. CASE: A 48-year-old woman was transferred to our institution with acute right lower limb ischemia and tissue loss. She underwent urgent iliac thrombectomy and was subsequently found to have right common iliac artery compression by a large uterine leiomyoma. She underwent successful resection of the tumor followed by endovascular iliac stent placement. CONCLUSION: This case emphasizes the importance of preoperative imaging when possible in the setting of acute arterial ischemia to evaluate for sources of extrinsic compression. Management requires correction of the etiology of extrinsic compression.

Pre-operative regional block anesthesia enhances operative strategy for arteriovenous fistula creation.

PURPOSE: We aim to assess the effect of regional block anesthesia on vein diameter, type of AVF placement, and fistula size and flow volume. METHODS: 30 patients presenting for AV access procedures were followed prospectively. Vein diameters via venous ultrasound and planned location for AV access were documented. Supraclavicular brachial plexus block was followed by repeat ultrasound and alterations in operative plan were noted. Patients returned to clinic for duplex ultrasound assessment. RESULTS: Average increase from baseline vein diameter with regional block was most pronounced in the lower cephalic (34%), upper cephalic (24.2%), and basilic veins (31.3%) and less in the brachial vein (8.7%). Type of AVF was modified following regional block in 14%. The rate of native AVF placement improved from 89% to 93% with regional block. Twenty-three AVF patients were available for follow-up (mean 24 weeks). Average fistula size was 7.9 mm (CI 6.9-8.9) and all patent fistulas developed flow volume >600 mL/min. Primary patency was attained in 83%. One thrombosis occurred after a basilic artery was lacerated during dialysis access. The average fistula increased 0.33 cm from post-block diameter (SD 0.22, P<.05). CONCLUSIONS: Vein diameter increases significantly in the basilic and cephalic veins following regional block anesthesia and may improve the rate of native fistula placement. Propensity to dilate after regional block anesthesia does not predict size of the fistula.

Aortic remodeling, volumetric analysis, and clinical outcomes of endoluminal exclusion of acute complicated type B thoracic aortic dissections.

OBJECTIVE: Structural changes within the aorta after thoracic endovascular aortic repair (TEVAR) for acute complicated type B thoracic aortic dissections (ABAD) remain unknown. This study reviewed and analyzed morphologic changes, volumetric data, and clinical outcomes of patients with ABAD. METHODS: Forty-one consecutive patients with ABAD, all with the volumetric analysis of aortic luminal changes and ≥1 year of follow-up, were treated as a part of a single-center U.S. Food and Drug Administration (FDA)-approved investigational device exemption (IDE) trial from 2002 to 2009. Indications were malperfusion in 17, rupture in 12, chest pain in 6, acute enlargement in 4, and uncontrolled hypertension in 2. Duration of symptoms was ≤14 days. Three-dimensional M2S computed tomography reconstructions (Medical MetRx Solutions, West Lebanon, NH) were analyzed for aortic volume and diameter changes, regression of the false lumen, and expansion of the true lumen. RESULTS: Emergent surgery was required in 17 (42%) patients, excluding one death at induction. Procedural success rate was 92.5%. The 30-day mortality was 4.9% for malperfusion, 4.9% for rupture, and 0% for all others, with late mortality of 0%, 9.8%, and 7.3%, respectively. Mean follow-up was 12.4 months. Permanent stroke and paraplegia rates were 4.9% (n = 2) and 0%. Ten of 12 secondary interventions were performed for 6 proximal endoleaks, 1 distal cuff endoleak, and 3 distal reperfusions. For the 33 patients without endoleaks, the true lumen volume increased by 29% at 1 month, 51% at 1 year, and 80% at 5 years. Volume regression of the false lumen was 69%, 76%, and 86%, respectively. The true lumen volume did not change at 1 month or 1 year in the endoleak group (n = 7) but increased 50% at 2 years after secondary intervention. A 10% reduction of abdominal aortic volume distal to endograft occurred over 5 years in the absence of endoleaks. CONCLUSIONS: TEVAR offers a promising solution to patients with ABAD. Aortic morphologic changes occur shortly after TEVAR and remain predictable up to 5 years with continuous expansion of the true lumen and regression of the false lumen. A lack of increase in the true lumen volume is associated with endoleaks or distal reperfusion.

Endovascular management of blunt aortic injury with an associated aberrant right subclavian artery: a report of three cases.

Traumatic rupture of the aorta in the rare setting of the aberrant right subclavian artery (ARSA) requires special consideration to prevent the occurrence of a devastating posterior cerebral circulation stroke. We present three cases managed by using an endovascular approach, with a discussion of important preoperative and operative issues. Three patients involved in motor vehicle collisions with multiple injuries were managed at two institutions. Computed tomography revealed transection of the aorta with incidental ARSA. All three cases were managed with a different approach. One patient did not undergo a preoperative bypass because imaging confirmed an adequate landing zone distal to the origin of the left subclavian artery. Two patients received preoperative right carotid-to-subclavian bypass for anticipated endograft coverage of both subclavian arteries to preserve single vertebral arterial flow. In one patient, an endovascular occlusion device was deployed in the ARSA before aortic endograft deployment. In the other, ARSA occlusion was performed 4 days later for a persistent type II endoleak. The patient who underwent bypass and preoperative ARSA occlusion suffered a fatal posterior circulation stroke shortly after surgery. The other two patients had no procedural complications and have not required any reinterventions at follow-up after 2 and 5 years. One patient is still undergoing rehabilitation after 5 years of follow-up for traumatic brain injury unrelated to the endograft repair. Although the incidence of ARSA is very low, preoperative imaging and assessment of cerebral blood flow are critical to prevent a perioperative stroke. Revascularization, if required to achieve a secure proximal landing zone, must be performed before endograft deployment. Bilateral subclavian revascularization is indicated if anomalies of the cerebral circulation are present.

A comparison between one- and two-stage brachiobasilic arteriovenous fistulas.

OBJECTIVES: Brachiobasilic arteriovenous fistulas (BBAVF) can be performed in one or two stages. We compared primary failure rates, as well as primary and secondary patency rates of one- and two-stage BBAVF at two institutions. METHODS: Patients undergoing one- and two-stage BBAVF at two institutions were compared retrospectively with respect to age, sex, body mass index, use of preoperative venous duplex ultrasound, diabetes, hypertension, and cause of end-stage renal disease. Categorical variables were compared using chi-square and Fisher's exact test, whereas the Wilcoxon rank-sum test was used to compare continuous variables. Patency rates were assessed using the Kaplan-Meier survival analysis and the Cox proportional hazards model with propensity analysis to determine hazard ratios. RESULTS: Ninety patients (60 one-stage and 30 two-stage) were identified. Mean follow-up was 14.2 months and the mean time interval between the first and second stage was 11.2 weeks. Although no significant difference in early failure existed (one-stage, 22.9% vs two-stage, 9.1%; P = .20), the two-stage BBAVF showed significantly improved primary functional patency at 1 year at 88% vs 61% (P = .047) (hazard ratio, 0.2 (95% confidence interval [CI], .04-.80; P = .03). Patency for one-stage BBAVF markedly decreased to 34% at 2 years compared with 88% for the two-stage procedure (P = .047). Median primary functional patency for one-stage BBAVF was 31 weeks (interquartile range [IQR], 11-54) vs 79 weeks (IQR, 29-131 weeks) for the two-stage procedure, respectively (P = .0015). Two-year secondary functional patency for one- and two-stage procedures were 41% and 94%, respectively (P = .015). CONCLUSIONS: Primary and secondary patency at 1 and 2 years as well as functional patency is improved with the two-stage BBAVF when compared with the one-stage procedure. Lower primary failure rates prior to dialysis with the two-stage procedure approached, but did not reach statistical significance. While reasons for these finding are unclear, certain technical aspects of the procedure may play a role.