A PROMPT Update on Partial REBOA: Initial Clinical Data and Overview of the DoD-Funded Partial REBOA Outcomes Multicenter ProspecTive (PROMPT) Study.

INTRODUCTION: Retrograde Endovascular Balloon Occlusion of the Aorta (REBOA) is an effective management for the transient responder, but the ischemic consequences of complete aortic occlusion currently limit its use. Multiple DoD-funded preclinical studies have clearly demonstrated that partial REBOA reduces distal ischemia to potentially extend safe occlusion times, while still providing effective temporization of noncompressible torso hemorrhage. Early versions of REBOA devices were designed to completely occlude the aorta and had little ability to provide partial occlusion. Recently, a new REBOA device (pREBOA-PRO) was designed specifically to allow for partial occlusion, with the hypothesis that this may reduce the complications of aortic occlusion and extend safe occlusion times while maintaining the benefits on cardiac and cerebrovascular circulation as well as reductions in resuscitation requirements. MATERIALS AND METHODS: To ascertain the impact of a new purpose-built partial REBOA device on the extension of safe occlusion time, the Partial REBOA Outcomes Multicenter ProspecTive (PROMPT) trial compared available data from the pREBOA-PRO with existing data from 200 clinical uses of pREBOA-PRO and available data in the AAST AORTA Registry were reviewed to design primary endpoints and clinical evidence for a prospective multi-center trial, the PROMPT Study. Together with the endpoints identified in preclinical studies of partial REBOA, primary endpoints for the PROMPT study were identified and power analyses were conducted to determine the target patient enrollment goals. RESULTS: Results from the clinical implementation of partial REBOA at a single trauma center were used to conduct the initial power analysis for the primary endpoint of Acute Kidney Injury (AKI) after prolonged occlusion. The rate of AKI after complete REBOA was 55% (12/20) compared to 33% (4/12) after partial REBOA (Madurska et al., 2021). With an alpha of 0.05 and power (ß) of 0.8, the projected sample size for comparison on a dichotomous outcome is 85 patients for the assessment of AKI. Initial power and endpoint analyses have been confirmed and extended with the ongoing analysis of partial and complete REBOA reported in the AORTA database. These analyses confirm preclinical findings which show that compared to complete REBOA, partial REBOA is associated with extended occlusion time in zone 1 (complete: 31 min vs. partial: 45 min, P = 0.003), lower rates of AKI after zone 1 occlusion (complete: 33% vs. partial: 19%, P = 0.05) and reduced resuscitation requirements (e.g., 25% reduction in pRBC administration: complete: 18 units vs. partial: 13 units, P = 0.02). CONCLUSIONS: The DoD-funded PROMPT study of partial REBOA will provide prospective observational clinical data on patients being treated with pREBOA-PRO. Outcomes will be stratified based on partial or complete occlusion to address whether partial REBOA has additional clinical benefits over complete REBOA, such as decreased distal ischemia, extension of safe occlusion time, improved hemodynamics during transition to and from occlusion, and reduced interoperative bleeding and blood product use. The results from this study are expected to confirm previous data demonstrating reduction of ischemic sequalae, improved transition to reperfusion, and reduced resuscitative requirements compared to complete REBOA.

Initial Experience with the Eclipse Double-Lumen Balloon Catheter for Embolization of Cranial Vascular Malformations.

BACKGROUND: Double lumen balloon catheters (DLBCs) have emerged as a potential alternative to single lumen balloon catheters for endovascular embolization of arteriovenous malformations (AVMs) and dural arteriovenous fistulas (dAVFs). This study describes our preliminary experience with the Eclipse 2L DLBC in treating AVMs and dAVFs. METHODS: Patients who underwent embolization of cranial dAVFs or AVMs at our institution from August 2021 to March 2024 were included. Spinal vascular malformations were excluded. Descriptive statistics were used to analyze procedural outcomes, technical nuances, and postoperative outcomes on follow-up. RESULTS: Twenty-five patients who underwent 38 embolization procedures (15 AVMs and 23 dAVFs) met criteria for inclusion in this study. The mean age of the cohort was 52.44 (standard deviation = 17.26), and 48% of the overall cohort (n = 13) was female. The average procedure times for AVMs and dAVFs were 80.4 minutes and 96.73 minutes, respectively. There was 1 instance of catheter entrapment. Two patients in the AVM cohort experienced mortality, and 1 experienced postoperative rupture. CONCLUSIONS: Our preliminary experience using the Eclipse 2L balloon catheter for Onyx embolization reported procedural outcomes comparable to other DLBCs despite relatively higher procedure times and radiation doses. Further long-term studies on its efficacy as primary modality in treating AVMs and dAVFs are encouraged.

Application of balloon occluder for specimen collection after descending duodenal ESD.

Endoscopic submucosal dissection (ESD) is a popular technique for resecting duodenal tumors. However, there is a risk of losing resected specimens during the procedure, particularly for lesions in the descending part of the duodenum. This study aims to introduce a simple and effective method for specimen collection after descending duodenal ESD using a self-made balloon occluder. The balloon occluder, made from a spray pipe and sterile rubber glove, is utilized to prevent the loss of resected specimens. The balloon is inflated under endoscopic visualization, occluding the descending lumen. With careful timing, the resected specimen can be safely collected by grasping it from the balloon using foreign forceps. This method has been successfully applied in several cases, demonstrating its practicality and efficacy. Further evaluation and validation of this technique in a larger patient population are warranted to establish its wider application in clinical practice.

Use of the Scepter Dual-Lumen Balloon Catheter for Transarterial Onyx Embolization of Cranial Dural Arteriovenous Fistulas.

BACKGROUND: Dual-lumen balloon microcatheters allow for controlled anterograde flow of Onyx while providing proximal flow arrest, thereby obviating the need for a second microcatheter or Onyx plug formation. We sought to assess the safety and efficiency of the Scepter dual-lumen balloon microcatheter in trans arterial Onyx embolization of intracranial dural arteriovenous fistulas (DAVFs). METHODS: We conducted a retrospective study of 36 patients with cranial DAVFs in which a Scepter balloon microcatheter was used between 2016 and 2023. RESULTS: Our study comprised 36 patients, mostly male (n = 23, 63.8%) with a mean age of 60.8 years. Most DAVFs were in the occipital lobe (n = 24, 66.7%), and 50% had external carotid artery supply from the occipital artery. Eighteen (50%) of DAVFs were Cognard type III and IV, respectively. About one third (33.3%, n = 12) of the DAVFs drained into the transverse sigmoid junction, and 27.7% (n = 10) had direct cortical venous drainage into supratentorial or posterior fossa veins. Complete occlusion was obtained in 22 (61.1%) patients while partial occlusion was observed in 14 (38.9%) patients. One patient (2.8%) developed a retroperitoneal hematoma. At final follow-up, complete occlusion was observed in 21 (77.8%) and partial occlusion was observed in 8 (22.2%). Recurrence was observed in 4/30 (13.3%) patients, and retreatment was required in 6 (18.75%) cases. CONCLUSIONS: At midterm follow-up, our study showed low morbidity and modest complete occlusion rates using the Scepter for transarterial Onyx embolization of high-grade DAVFs.

Temporary Ureter Occlusion with Simultaneous Urinary Diversion via a Single-Access Route Using a 4-French Balloon Catheter and a Pigtail Nephrostomy Drainage Catheter.

Background and Objectives: This study evaluated the efficacy and safety of temporary ureteral occlusion combined with urinary diversion using a single-access route created by inserting a balloon catheter through a pigtail nephrostomy drainage catheter. With this approach, we aimed to offer an alternative for patients with ureteral leaks who are suboptimal surgical candidates. Materials and Methods: This retrospective study included nine patients (eight of which were bilateral cases and one was unilateral, totaling seventeen cases) who underwent the surgery between September 2023 and March 2024. The method involved gaining percutaneous access to the pelvicalyceal system, inserting a 4-French Fogarty balloon catheter through a pigtail nephrostomy catheter, and inflating the balloon at the proximal or mid-ureter. Results: All 17 cases achieved technical successful with no major complications. The procedure effectively relieved symptoms associated with urinary leakage in most patients. However, the significant deflation of the balloon catheter occurred in five cases (29.4%), with three (17.6%) experiencing complete deflation. In these five cases, the final balloon size was 5.81 mm (range: 0-8.9 mm), confirming a 25.0% decrease in size from pre- to post-procedure. Ureteral occlusion was 28.3 d long on average (range: 8-57 d). All patients experienced symptom relief during temporary ureteral occlusion. Except for two patients lost to follow-up, three patients showed symptom improvement with only PCN and four patients underwent surgical closure of the fistula tract before or after balloon catheter removal. Conclusions: This study confirms that this approach is safe and effective.

Focal intra-colon cooling reduces organ injury and systemic inflammation after REBOA management of lethal hemorrhage in rats.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a lifesaving maneuver for the management of lethal torso hemorrhage. However, its prolonged use leads to distal organ ischemia-reperfusion injury (IRI) and systemic inflammatory response syndrome (SIRS). The objective of this study is to investigate the blood-based biomarkers of IRI and SIRS and the efficacy of direct intestinal cooling in the prevention of IRI and SIRS. A rat lethal hemorrhage model was produced by bleeding 50% of the total blood volume. A balloon catheter was inserted into the aorta for the implementation of REBOA. A novel TransRectal Intra-Colon (TRIC) device was placed in the descending colon and activated from 10 min after the bleeding to maintain the intra-colon temperature at 37 °C (TRIC37°C group) or 12 °C (TRIC12°C group) for 270 min. The upper body temperature was maintained at as close to 37 °C as possible in both groups. Blood samples were collected before hemorrhage and after REBOA. The organ injury biomarkers and inflammatory cytokines were evaluated by ELISA method. Blood based organ injury biomarkers (endotoxin, creatinine, AST, FABP1/L-FABP, cardiac troponin I, and FABP2/I-FABP) were all drastically increased in TRIC37°C group after REBOA. TRIC12°C significantly downregulated these increased organ injury biomarkers. Plasma levels of pro-inflammatory cytokines TNF-α, IL-1b, and IL-17F were also drastically increased in TRIC37°C group after REBOA. TRIC12°C significantly downregulated the pro-inflammatory cytokines. In contrast, TRIC12°C significantly upregulated the levels of anti-inflammatory cytokines IL-4 and IL-10 after REBOA. Amazingly, the mortality rate was 100% in TRIC37°C group whereas 0% in TRIC12°C group after REBOA. Directly cooling the intestine offered exceptional protection of the abdominal organs from IRI and SIRS, switched from a harmful pro-inflammatory to a reparative anti-inflammatory response, and mitigated mortality in the rat model of REBOA management of lethal hemorrhage.

Randomized Trial of Fetal Surgery for Severe Left Diaphragmatic Hernia.

BACKGROUND: Observational studies have shown that fetoscopic endoluminal tracheal occlusion (FETO) has been associated with increased survival among infants with severe pulmonary hypoplasia due to isolated congenital diaphragmatic hernia on the left side, but data from randomized trials are lacking. METHODS: In this open-label trial conducted at centers with experience in FETO and other types of prenatal surgery, we randomly assigned, in a 1:1 ratio, women carrying singleton fetuses with severe isolated congenital diaphragmatic hernia on the left side to FETO at 27 to 29 weeks of gestation or expectant care. Both treatments were followed by standardized postnatal care. The primary outcome was infant survival to discharge from the neonatal intensive care unit. We used a group-sequential design with five prespecified interim analyses for superiority, with a maximum sample size of 116 women. RESULTS: The trial was stopped early for efficacy after the third interim analysis. In an intention-to-treat analysis that included 80 women, 40% of infants (16 of 40) in the FETO group survived to discharge, as compared with 15% (6 of 40) in the expectant care group (relative risk, 2.67; 95% confidence interval [CI], 1.22 to 6.11; two-sided P = 0.009). Survival to 6 months of age was identical to the survival to discharge (relative risk, 2.67; 95% CI, 1.22 to 6.11). The incidence of preterm, prelabor rupture of membranes was higher among women in the FETO group than among those in the expectant care group (47% vs. 11%; relative risk, 4.51; 95% CI, 1.83 to 11.9), as was the incidence of preterm birth (75% vs. 29%; relative risk, 2.59; 95% CI, 1.59 to 4.52). One neonatal death occurred after emergency delivery for placental laceration from fetoscopic balloon removal, and one neonatal death occurred because of failed balloon removal. In an analysis that included 11 additional participants with data that were available after the trial was stopped, survival to discharge was 36% among infants in the FETO group and 14% among those in the expectant care group (relative risk, 2.65; 95% CI, 1.21 to 6.09). CONCLUSIONS: In fetuses with isolated severe congenital diaphragmatic hernia on the left side, FETO performed at 27 to 29 weeks of gestation resulted in a significant benefit over expectant care with respect to survival to discharge, and this benefit was sustained to 6 months of age. FETO increased the risks of preterm, prelabor rupture of membranes and preterm birth. (Funded by the European Commission and others; TOTAL ClinicalTrials.gov number, NCT01240057.).

Randomized Trial of Fetal Surgery for Moderate Left Diaphragmatic Hernia.

BACKGROUND: Fetoscopic endoluminal tracheal occlusion (FETO) has been associated with increased postnatal survival among infants with severe pulmonary hypoplasia due to isolated congenital diaphragmatic hernia on the left side, but data are lacking to inform its effects in infants with moderate disease. METHODS: In this open-label trial conducted at many centers with experience in FETO and other types of prenatal surgery, we randomly assigned, in a 1:1 ratio, women carrying singleton fetuses with a moderate isolated congenital diaphragmatic hernia on the left side to FETO at 30 to 32 weeks of gestation or expectant care. Both treatments were followed by standardized postnatal care. The primary outcomes were infant survival to discharge from a neonatal intensive care unit (NICU) and survival without oxygen supplementation at 6 months of age. RESULTS: In an intention-to-treat analysis involving 196 women, 62 of 98 infants in the FETO group (63%) and 49 of 98 infants in the expectant care group (50%) survived to discharge (relative risk , 1.27; 95% confidence interval [CI], 0.99 to 1.63; two-sided P = 0.06). At 6 months of age, 53 of 98 infants (54%) in the FETO group and 43 of 98 infants (44%) in the expectant care group were alive without oxygen supplementation (relative risk, 1.23; 95% CI, 0.93 to 1.65). The incidence of preterm, prelabor rupture of membranes was higher among women in the FETO group than among those in the expectant care group (44% vs. 12%; relative risk, 3.79; 95% CI, 2.13 to 6.91), as was the incidence of preterm birth (64% vs. 22%, respectively; relative risk, 2.86; 95% CI, 1.94 to 4.34), but FETO was not associated with any other serious maternal complications. There were two spontaneous fetal deaths (one in each group) without obvious cause and one neonatal death that was associated with balloon removal. CONCLUSIONS: This trial involving fetuses with moderate congenital diaphragmatic hernia on the left side did not show a significant benefit of FETO performed at 30 to 32 weeks of gestation over expectant care with respect to survival to discharge or the need for oxygen supplementation at 6 months. FETO increased the risks of preterm, prelabor rupture of membranes and preterm birth. (Funded by the European Commission and others; TOTAL ClinicalTrials.gov number, NCT00763737.).

A REBOA Complication: EtCO2 Is Not Just a Marker of Cardiac Output.

We describe an as yet undescribed complication, namely, the perforation of the balloon at a distance from its introduction and the use of EtCO2 to suspect the diagnosis. Following a high-kinetic motorcycle accident, a 25-year-old patient was admitted in our level 1 trauma center, and benefited from a resuscitation thoracotomy followed by a REBOA catheter in zone 3. The use of a small caliber introducer could be responsible for balloon injury. EtCO2 is not only a marker of cardiac output and its sudden increase in this situation should raise questions about the recirculation of ischemia product and therefore the effectiveness of the occlusion balloon.

Is cerebral perfusion maintained during full and partial resuscitative endovascular balloon occlusion of the aorta in hemorrhagic shock conditions?

BACKGROUND: Partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) is a technology that occludes aortic flow and allows for controlled deflation and restoration of varying distal perfusion. Carotid flow rates (CFRs) during partial deflation are unknown. Our aim was to measure CFR with the different pREBOA balloon volumes and correlate those to the proximal mean arterial pressure (PMAP) and a handheld pressure monitoring device (COMPASS; Mirador Biomedical, Seattle, WA). METHODS: Ten swine underwent a hemorrhagic injury model with carotid and iliac arterial pressures monitored via arterial lines. Carotid and aortic flow rates were monitored with Doppler flow probes. A COMPASS was placed to monitor proximal pressure. The pREBOA was inflated for 15 minutes then partially deflated for an aortic flow rate of 0.7 L/min for 45 minutes. It was then completely deflated. Proximal mean arterial pressures and CFR were measured, and correlation was evaluated. Correlation between CRF and COMPASS measurements was evaluated. RESULTS: Carotid flow rate increased 240% with full inflation. Carotid flow rate was maintained at 100% to 150% of baseline across a wide range of partial deflation. After full deflation, CFR transiently decreased to 45% to 95% of baseline. There was strong positive correlation (r > 0.85) between CFR and PMAP after full inflation, and positive correlation with partial inflation (r > 0.7). Carotid flow rate had strong correlation with the COMPASS with full REBOA (r > 0.85) and positive correlation with pREBOA (r > 0.65). CONCLUSION: Carotid flow rate is increased in a hemorrhagic model during full and partial inflation of the pREBOA and correlates well with PMAP. Carotid perfusion appears maintained across a wide range of pREBOA deflation and could be readily monitored with a handheld portable COMPASS device instead of a standard arterial line setup.

Novel intraperitoneal hemostasis device prolongs survival in a swine model of noncompressible abdominal hemorrhage.

BACKGROUND: Noncompressible torso hemorrhage (NCTH) of the abdomen is a challenge to rapidly control and treat in the prehospital and emergency department settings. In this pilot study, we developed a novel intraperitoneal hemostasis device (IPHD) prototype and evaluated its ability for slowing NCTH and prolonging survival in a porcine model of lethal abdominal multiorgan hemorrhage. METHODS: Yorkshire male swine (N = 8) were instrumented under general anesthesia for monitoring of hemodynamics and blood sampling. Animals were subjected to a 30% controlled arterial hemorrhage followed by lacerating combinations of the liver, spleen, and kidney. The abdomen was closed and after 2 minutes of NCTH, and the IPHD was inserted into the peritoneal cavity via an introducer (n = 5). The balloon was inflated and maintained for 60 minutes. At 60 minutes postdeployment, the balloon was deflated and removed, and blood resuscitation was initiated followed by gauze packing for hemostasis. The remaining animals (n = 3) were used as controls and subjected to the same injury without intervention. RESULTS: All animals managed with IPHD intervention (5 of 5 swine) survived the duration of the intervention period (60 minutes), while all control animals (3 of 3 swine) died at a time range of 15 to 43 minutes following organ injury (p = 0.0042). Animals receiving IPHD remained hemodynamically stable with a mean arterial pressure range of 44.86 to 55.10 mm Hg and experienced increased cardiac output and decreased shock index after treatment. Controls experienced hemodynamic decline in all parameters until endpoints were met. Upon IPHD deflation and removal, all treated animals began to hemorrhage again and expired within 2 to 132 minutes despite packing. CONCLUSION: Our data show that the IPHD concept is capable of prolonging survival by temporarily stanching lethal NCTH of the abdomen. This device may be an effective temporary countermeasure to NCTH of the abdomen that could be deployed in the prehospital environment or as a bridge to more advanced therapy.