Autonomous navigation of catheters and guidewires in mechanical thrombectomy using inverse reinforcement learning.

PURPOSE: Autonomous navigation of catheters and guidewires can enhance endovascular surgery safety and efficacy, reducing procedure times and operator radiation exposure. Integrating tele-operated robotics could widen access to time-sensitive emergency procedures like mechanical thrombectomy (MT). Reinforcement learning (RL) shows potential in endovascular navigation, yet its application encounters challenges without a reward signal. This study explores the viability of autonomous guidewire navigation in MT vasculature using inverse reinforcement learning (IRL) to leverage expert demonstrations. METHODS: Employing the Simulation Open Framework Architecture (SOFA), this study established a simulation-based training and evaluation environment for MT navigation. We used IRL to infer reward functions from expert behaviour when navigating a guidewire and catheter. We utilized the soft actor-critic algorithm to train models with various reward functions and compared their performance in silico. RESULTS: We demonstrated feasibility of navigation using IRL. When evaluating single- versus dual-device (i.e. guidewire versus catheter and guidewire) tracking, both methods achieved high success rates of 95% and 96%, respectively. Dual tracking, however, utilized both devices mimicking an expert. A success rate of 100% and procedure time of 22.6 s were obtained when training with a reward function obtained through 'reward shaping'. This outperformed a dense reward function (96%, 24.9 s) and an IRL-derived reward function (48%, 59.2 s). CONCLUSIONS: We have contributed to the advancement of autonomous endovascular intervention navigation, particularly MT, by effectively employing IRL based on demonstrator expertise. The results underscore the potential of using reward shaping to efficiently train models, offering a promising avenue for enhancing the accessibility and precision of MT procedures. We envisage that future research can extend our methodology to diverse anatomical structures to enhance generalizability.

Gamification-augmented home-based exercise for peripheral artery disease: Rationale and design of the GAMEPAD Study.

BACKGROUND: Supervised exercise therapy improves walking performance, functional capacity, and quality of life in patients with peripheral artery disease (PAD). However, few patients with PAD are enrolled in supervised exercise programs, and there are a number of logistical and financial barriers to their participation. A home-based walking intervention is likely to be more accessible to patients with PAD, but no fully home-based walking program has demonstrated efficacy. Concepts from behavioral economics have been used to design scalable interventions that increase daily physical activity in patients with atherosclerotic vascular disease, but whether a similar program would be effective in patients with PAD is uncertain. STUDY DESIGN AND OBJECTIVES: GAMEPAD (NCT04536012) is a pragmatic, virtual, randomized controlled trial designed to evaluate the effectiveness of a gamification strategy informed by concepts from behavioral economics to increase daily physical activity in patients with PAD who are seen in cardiology and vascular surgery clinics affiliated with the University of Pennsylvania Health System. Patients are contacted by email or text message, and complete enrollment and informed consent on the Penn Way to Health online platform. A GAMEPAD substudy will evaluate the effectiveness of opt-in versus opt-out framing when approaching patients for study participation. Patients are then provided with a wearable fitness tracker, establish a baseline daily step count, set a goal to increase daily step count by 33%-50%, and are randomized 1:1 to the gamification or control arms. Interventions continue for 16 weeks, including a 4-week period during which goal step count is gradually increased in the gamification arm, with follow-up for an additional 8 weeks to evaluate the durability of behavior change. The trial has met its enrollment goal of 102 participants, with a primary endpoint of change from baseline in daily steps over the 16-week intervention period. Key secondary endpoints include change from baseline in daily steps over the 8-week postintervention follow-up period and changes in patient-reported measures of PAD symptoms and quality of life over the intervention and follow-up periods. CONCLUSIONS: GAMEPAD is a virtual, pragmatic randomized clinical trial of a novel, fully home-based walking intervention informed by concepts from behavioral economics to increase physical activity and PAD-specific quality of life in patients with PAD. Its results will have important implications for the application of behavioral economic concepts to scalable home-based strategies to promote physical activity in patients with PAD and other disease processes where physical activity is limited by exertional symptoms. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov; NCT04536012.

Technique and Outcomes of Concomitant Aortic and Caval Resection and Reconstruction for Retroperitoneal Tumors.

BACKGROUND: Major vascular involvement is often considered a contraindication to resection of malignant tumors, but in highly selected patients, it can be performed safely, with results that are highly dependent upon the tumor biology. Resection of both the aorta and inferior vena cava (IVC) is a rare undertaking, requiring both favorable tumor biology and a patient fit for a substantial surgical insult; nevertheless, it provides the possibility of a cure. METHODS: Patients requiring resection and reconstruction of both the aorta and IVC from 2009 through 2019 at 2 university medical centers were included. Patient characteristics, operative technique, and outcomes were retrospectively collected. RESULTS: We identified 9 patients, all with infrarenal reconstruction or repair of the aorta and IVC. All cases were performed with systemic heparinization and required simultaneous aortic and caval cross-clamping for tumor resection. No temporary venous or arterial bypass was used. Since arterial reperfusion with the IVC clamped was poorly tolerated in 1 patient, venous reconstruction was typically completed first. Primary repair was performed in 1 patient, while 8 required replacements. In 2 patients, aortic homograft was used for replacement of both the aortoiliac and iliocaval segments in contaminated surgical fields. In the remaining 6, Dacron was used for arterial replacement; either Dacron (n = 2) or polytetrafluoroethylene (n = 4) were used for venous replacement. Patients were discharged after a median stay of 8 days (range: 5-16). At median follow-up of 17 months (range 3-79 months), 2 patients with paraganglioma and 1 patient with Leydig cell carcinoma had cancer recurrences. Venous reconstructions occluded in 3 patients (38%), although symptoms were minimal. One patient presented acutely with a thrombosed iliac artery limb and bilateral common iliac artery anastomotic stenoses, treated successfully with thrombolysis and stenting. CONCLUSIONS: Patients with tumor involving both the aorta and IVC can be successfully treated with resection and reconstruction. En bloc tumor resection, restoration of venous return before arterial reconstruction, and most importantly, careful patient selection, all contribute to positive outcomes in this otherwise incurable population.

Artificial intelligence in the autonomous navigation of endovascular interventions: a systematic review.

Background: Autonomous navigation of catheters and guidewires in endovascular interventional surgery can decrease operation times, improve decision-making during surgery, and reduce operator radiation exposure while increasing access to treatment. Objective: To determine from recent literature, through a systematic review, the impact, challenges, and opportunities artificial intelligence (AI) has for the autonomous navigation of catheters and guidewires for endovascular interventions. Methods: PubMed and IEEEXplore databases were searched to identify reports of AI applied to autonomous navigation methods in endovascular interventional surgery. Eligibility criteria included studies investigating the use of AI in enabling the autonomous navigation of catheters/guidewires in endovascular interventions. Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), articles were assessed using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). PROSPERO: CRD42023392259. Results: Four hundred and sixty-two studies fulfilled the search criteria, of which 14 studies were included for analysis. Reinforcement learning (RL) (9/14, 64%) and learning from expert demonstration (7/14, 50%) were used as data-driven models for autonomous navigation. These studies evaluated models on physical phantoms (10/14, 71%) and in-silico (4/14, 29%) models. Experiments within or around the blood vessels of the heart were reported by the majority of studies (10/14, 71%), while non-anatomical vessel platforms "idealized" for simple navigation were used in three studies (3/14, 21%), and the porcine liver venous system in one study. We observed that risk of bias and poor generalizability were present across studies. No procedures were performed on patients in any of the studies reviewed. Moreover, all studies were limited due to the lack of patient selection criteria, reference standards, and reproducibility, which resulted in a low level of evidence for clinical translation. Conclusion: Despite the potential benefits of AI applied to autonomous navigation of endovascular interventions, the field is in an experimental proof-of-concept stage, with a technology readiness level of 3. We highlight that reference standards with well-identified performance metrics are crucial to allow for comparisons of data-driven algorithms proposed in the years to come. Systematic review registration: identifier: CRD42023392259.

Comparative verification of control methodology for robotic interventional neuroradiology procedures.

PURPOSE: The use of robotics is emerging for performing interventional radiology procedures. Robots in interventional radiology are typically controlled using button presses and joystick movements. This study identified how different human-robot interfaces affect endovascular surgical performance using interventional radiology simulations. METHODS: Nine participants performed a navigation task on an interventional radiology simulator with three different human-computer interfaces. Using Simulation Open Framework Architecture we developed a simulation profile of vessels, catheters and guidewires. We designed and manufactured a bespoke haptic interventional radiology controller for robotic systems to control the simulation. Metrics including time taken for navigation, number of incorrect catheterisations, number of catheter and guidewire prolapses and forces applied to vessel walls were measured and used to characterise the interfaces. Finally, participants responded to a questionnaire to evaluate the perception of the controllers. RESULTS: Time taken for navigation, number of incorrect catheterisations and the number of catheter and guidewire prolapses, showed that the device-mimicking controller is better suited for controlling interventional neuroradiology procedures over joystick control approaches. Qualitative metrics also showed that interventional radiologists prefer a device-mimicking controller approach over a joystick approach. CONCLUSION: Of the four metrics used to compare and contrast the human-robot interfaces, three conclusively showed that a device-mimicking controller was better suited for controlling interventional neuroradiology robotics.

Ab Initio Calculations on the Ground and Excited Electronic States of Thorium-Ammonia, Thorium-Aza-Crown, and Thorium-Crown Ether Complexes.

Positively charged metal-ammonia complexes are known to host peripheral, diffuse electrons around their molecular skeleton. The resulting neutral species form materials known as expanded or liquid metals. Alkali, alkaline earth, and transition metals have been investigated previously in experimental and theoretical studies of both the gas and condensed phase. This work is the first ab initio exploration of an f-block metal-ammonia complex. The ground and excited states are calculated for Th0-3+ complexes with ammonia, crown ethers, and aza-crown ethers. For Th3+ complexes, the one valence electron Th populates the metal's 6d or 7f orbitals. For Th0-2+, the additional electrons prefer occupation of the outer s- and p-type orbitals of the complex, except Th(NH3)10, which uniquely places all four electrons in outer orbitals of the complex. Although thorium coordinates up to ten ammonia ligands, octa-coordinated complexes are more stable. Crown ether complexes have a similar electronic spectrum to ammonia complexes, but excitations of electrons in the outer orbitals of the complex are higher in energy. Aza-crown ethers disfavor the orbitals perpendicular to the crowns, attributed to the N-H bonds pointing along the plane of the crowns.

Portalvein reconstruction with a cadaveric descending thoracic aortic homograft.

Improvements in chemoradiotherapy have rendered complex pancreatic cancers involving the portal vein (PV) amenable to resection. PV reconstruction (PVR) is an essential component. Various conduits have been proposed; however, the optimal choice remains unknown. Fourteen patients underwent PVR with a cadaveric descending thoracic aortic homograft from 2014 to 2020. The primary diagnosis was pancreatic cancer. The splenic vein was ligated in seven patients (50%). The 30-day and 3-, 12-, and 24-month primary patency rates were 100%, 86%, 76%, and 76%, respectively. We found a cadaveric descending thoracic aortic homograft is an excellent conduit for PVR, given the optimal size, rapidly availability, favorable risk profile, and absence of harvest site complications.

The nature of supermolecular bonds: Investigating hydrocarbon linked beryllium solvated electron precursors.

Beryllium ammonia complexes Be(NH3)4 are known to bear two diffuse electrons in the periphery of a Be(NH3)4 2+ skeleton. The replacement of one ammonia with a methyl group forms CH3Be(NH3)3 with one peripheral electron, which is shown to maintain the hydrogenic-type shell model observed for Li(NH3)4. Two CH3Be(NH3)3 monomers are together linked by aliphatic chains to form strongly bound beryllium ammonia complexes, (NH3)3Be(CH2)nBe(NH3)3, n = 1-6, with one electron around each beryllium ammonia center. In the case of a linear carbon chain, this system can be seen as the analog of two hydrogen atoms approaching each other at specific distances (determined by n). We show that the two electrons occupy diffuse s-type orbitals and can couple exactly as in H2 in either a triplet or singlet state. For long hydrocarbon chains, the singlet is an open-shell singlet nearly degenerate with the triplet spin state, which transforms to a closed-shell singlet for n = 1 imitating the σ-covalent bond of H2. The biradical character of the system is analyzed, and the singlet-triplet splitting is estimated as a function of n based on multi-reference calculations. Finally, we consider the case of bent hydrocarbon chains, which allows the closer proximity of the two diffuse electrons for larger chains and the formation of a direct covalent bond between the two diffuse electrons, which happens for two Li(NH3)4 complexes converting the open-shell to closed-shell singlets. The energy cost for bending the hydrocarbon chain is nearly compensated by the formation of the weak covalent bond rendering bent and linear structures nearly isoenergetic.

The Differential Impact of Medicaid Expansion on Disparities in Outcomes Following Peripheral Vascular Intervention.

BACKGROUND: Peripheral artery disease (PAD) disproportionately affects nonwhite, Hispanic/Latino, and low socioeconomic status patients, who are less likely to have insurance and routine healthcare visits. Medicaid expansion (ME) has improved insurance rates and access to care, potentially benefitting these patients. We sought to assess the impact of ME on disparities in outcomes after peripheral vascular intervention (PVI) for PAD. METHODS: A retrospective analysis of prospectively-collected Vascular Quality Initiative PVI procedures between 2011 and 2019 was conducted. The sample was restricted to first-record procedures in adults under the age 65 in states that expanded Medicaid on January 1, 2014 (ME group) or had not expanded before January 1, 2019 (non-expansion [NE] group). ME and NE groups were compared between pre-expansion (2011-2013) and post-expansion (2014- 2019) time periods to assess baseline demographic and operative differences. We used difference-in-differences multivariable logistic regression adjusted for patient factors and clinical center and year fixed effects. Our primary outcome was 1-year major amputation. Secondary outcomes included trends in presentation, 30-day mortality, 1-year mortality, and 1-year primary and secondary patency. Outcomes were stratified by race and ethnicity. RESULTS: We examined 34,313 PVI procedures, including 20,378 with follow-up data. Rates of Medicaid insurance increased post-expansion in ME and NE states (ME 16.7% to 23.0%, P < 0.001; NE 10.0% to 11.9%, P = 0.013) while rates of self-pay decreased in ME states only (ME 4.6% to 1.8%, P < 0.001; NE 8.1% to 8.4%, P = 0.620). Adjusted difference-in-differences analysis revealed lower odds of urgent/emergent PVI among all patients and all nonwhite patients in ME states post-expansion compared to NE states (all: odds ratio [OR] 0.53 [95% confidence interval 0.33-0.87], P = 0.011; nonwhite: OR 0.41 [0.19-0.88], P = 0.023). No differences were observed for 1-year major amputation (OR 0.70 [0.43-1.14], P = 0.152), primary patency (OR 0.93 [0.63-1.38], P = 0.726), or secondary patency (OR 1.29 [0.69-2.41], P = 0.431). Odds of 1-year mortality were higher in ME states post-expansion compared to NE states (OR 2.50 [1.07-5.87], P = 0.035), although 30-day mortality was not different (OR 2.04 [0.60-6.90], P = 0.253). Notably, odds of 1-year major amputation among Hispanic/Latino patients decreased in ME states post-expansion compared to NE states (OR 0.11 [0.01-0.86], P = 0.036). CONCLUSIONS: ME was associated with lower odds of 1-year major amputation among Hispanic/Latino patients who underwent PVI for PAD. ME was also associated with lower odds of urgent/emergent procedures among patients overall and nonwhite patients specifically. However, 1-year mortality increased in the overall cohort. Further study is needed to corroborate our findings that ME may have benefits for certain underserved populations with PAD.

A large series of true pancreaticoduodenal artery aneurysms.

INTRODUCTION: True pancreaticoduodenal artery aneurysms (PDAAs) are rare, and prior reports often fail to distinguish true aneurysms from pseudoaneuryms. We sought to characterize all patients who presented to our health system from 2004 to 2019 with true PDAAs, with a focus on risk factors, interventions, and patient outcomes. METHODS: Patients were identified by querying a single health system picture archiving and communication system database for radiographic reports noting a PDAA. A retrospective chart review was performed on all identified patients. Patients with pseudoaneurysm, identified as those with a history of pancreatitis, abdominal malignancy, hepatopancreaticobiliary surgery, or abdominal trauma, were excluded. Continuous variables were compared using t-tests, and categorical variables were compared using Fisher's exact tests. RESULTS: A total of 59 true PDAAs were identified. Forty aneurysms (68%) were intact (iPDAAs) and 19 (32%) were ruptured (rPDAAs) at presentation. The mean size of rPDAAs was 16.4 mm (median size, 14.0 mm; range, 10-42 mm), and the mean size of iPDAAs was 19.4 mm (median size, 17.5 mm; range, 8-88 mm); this difference was not statistically significant (P = .95). Significant celiac disease (occlusion or >70% stenosis) was noted in 39 aneurysms (66%). Those with rupture were less likely to have significant celiac disease (42% vs 78%; P = .017) and less likely to have aneurysmal wall calcifications (6% vs 53%; P = .002). Thirty-seven patients underwent intervention (63%), with eight (22%) undergoing concomitant hepatic revascularization (two stents and six bypasses) due to the presence of celiac disease. Eighteen patients with occluded celiac arteries underwent aneurysm intervention; of those, 11 were performed without hepatic revascularization (61.1%). Those with rPDAAs experienced an aneurysm-related mortality of 10.5%, whereas those with iPDAAs experienced a rate of 5.6%. One patient with celiac occlusion and PDA rupture who did not undergo hepatic artery bypass expired postoperatively from hepatic ischemia. rPDAAs showed a trend toward the increased need for aneurysm-related endovascular or open reintervention, but this was not statistically significant (47% vs 28%; P = .13). CONCLUSIONS: These findings support previous reports that the rupture risk of PDAAs is independent of size, their development is often associated with significant celiac stenosis or occlusion, and rupture risk appears decreased in patients with concomitant celiac disease or aneurysm wall calcifications. Endovascular intervention is the preferred initial treatment for both iPDAAs and rPDAAs, but reintervention rates are high in both groups. The role for hepatic revascularization remains uncertain, but it does not appear to be mandatory in all patients with complete celiac occlusion who undergo PDAA interventions.

Point-of-Care Ultrasound to Assess Gastric Content in Pediatric Emergency Department Procedural Sedation Patients.

OBJECTIVES: There is debate regarding the timing of procedural sedation and analgesia (PSA) in relation to fasting status. Point-of-care ultrasound (POCUS) provides the ability to measure gastric content and is being used as a surrogate for aspiration risk in anesthesia. We sought to evaluate the gastric content of pediatric emergency department (PED) patients undergoing PSA using POCUS. METHODS: We performed a prospective observational study using a convenience sample of pediatric patients undergoing PSA between July 1, 2018, and June 30, 2019. Following a brief history, gastric content was measured using POCUS in both supine and right lateral decubitus positions at 2-hour intervals until the time of PSA. Qualitative content and calculated volume were classified based on the Perlas Model of anesthesia "Risk" assessment. RESULTS: Ninety-three patients were enrolled with 61.3% male and mean age of 6.5 years. Gastric content was determined in 92 patients. There were 79.3% that had "high risk" content at the time of PSA, with a median fasting time of 6.25 hours and no serious adverse events. Fasting duration had a weak to moderate ability to predict "risk" category (area under the curve = 0.73), with no patient (n = 17) who underwent multiple evaluations awaiting PSA progressing from "high" to "low risk." CONCLUSIONS: The majority of PED patients undergoing PSA at our institution had "high risk" gastric content with no clinically significant change occurring during serial evaluations. This calls into question the utility of delaying PSA based upon fasting status and lends support to a more comprehensive risk-benefit approach when planning pediatric PSA.

Tranexamic Acid in Foot and Ankle Surgery: A Topical Review and Value Analysis.

Tranexamic acid (TXA) has become a commonly used perioperative intervention in total joint arthroplasty, shoulder and knee arthroscopy, and spinal procedures in order to minimize blood loss, hematoma formation, hemarthrosis, and wound healing complications. There is a potential role for TXA use in foot and ankle procedures, with limited studies suggesting a potential benefit in minimizing postoperative wound complications and blood loss without an increased risk of thromboembolic events. In light of the profound clinical and financial impact of TXA use in other orthopaedic subspecialties and the early successes in foot and ankle surgery, we aim to provide more information about TXA and its use in foot and ankle surgery. Therefore, the purpose of this review is to perform a comprehensive literature review on the topic of TXA use in foot and ankle procedures in order to describe the pertinent available literature on the use of TXA in orthopaedic surgery and its implications specifically in foot and ankle surgery. It is our aim to identify potential benefits and shortcomings in the available evidence on TXA use for foot and ankle surgery in hopes to (1) best inform foot and ankle surgeons where beneficial and safe and (2) inspire further research on this topic as it relates to clinical management for foot and ankle patients.Levels of Evidence: Level IV.

The Hyperattenuating Crescent Sign Is Not Necessarily a Sign of Impending Aortic Aneurysm Rupture.

BACKGROUND: The "crescent sign" is a hyperattenuating crescent-shaped region on CT within the mural thrombus or wall of an aortic aneurysm. Although it has previously been associated with aneurysm instability or impending rupture, the literature is largely based on retrospective analyses of urgently repaired aneurysms. We strove to more rigorously assess the association between an isolated "crescent sign" and risk of impending aortic rupture. METHODS: Patients were identified by querying a single health system PACS database for radiology reports noting a crescent sign. Adult patients with a CT demonstrating a descending thoracic, thoracoabdominal, or abdominal aortic aneurysm and "crescent sign" between 2004 and 2019 were included, with exclusion of those showing definitive signs of aortic rupture on imaging. RESULTS: A total of 82 patients were identified. Aneurysm size was 7.1 ± 2.0 cm. Thirty patients had emergent or urgent repairs during their index admission (37%), 19 had elective repairs at a later date (23%), and 33 patients had no intervention due to either patient choice or prohibitive medical comorbidities (40%). Patients without intervention had a median follow up of 275 days before death or loss to follow up. In patients undergoing elective intervention, 6,968 patient-days elapsed between presentation and repair, with zero episodes of acute rupture (median 105 days). Patients undergoing elective repair had smaller aneurysms compared to those who underwent emergent/urgent repair (6.2 ± 1.3 vs. 7.7 ± 2.1 cm, P = 0.008). No surgical candidate with an aneurysm smaller than 8 cm ruptured. There were 31 patients with previous axial imaging within 2 years prior to presentation with a "crescent sign," with mean aneurysm growth rate of 0.85 ± 0.62 cm per 6 months [median 0.65, range 0-2.6]. Those with aneurysms sized below 5.5 cm displayed decreased aneurysm growth compared to patients with aneurysm's sized 5.5-6.5 cm or patients with aneurysms greater than 6.5 cm (0.12 vs. 0.64 vs. 1.16 cm per 6 months, P= 0.002). CONCLUSIONS: The finding of an isolated radiographic "crescent sign" without other signs of definitive aortic rupture (i.e., hemothorax, aortic wall disruption, retroperitoneal bleeding) is not necessarily an indicator of impending aortic rupture, but may be found in the setting of rapid aneurysm growth. Many factors, including other associated radiographic findings, aneurysm size and growth rate, and patient symptomatology, should guide aneurysm management in these patients. We found that patients with minimal symptoms, aneurysm sizes below 6.5 cm, and no further imaging findings of aneurysm instability, such as periaortic fat stranding, can be successfully managed with elective intervention after optimization of comorbid factors with no evidence of adverse outcomes.

Repurposing an adenine riboswitch into a fluorogenic imaging and sensing tag.

Fluorogenic RNA aptamers are used to genetically encode fluorescent RNA and to construct RNA-based metabolite sensors. Unlike naturally occurring aptamers that efficiently fold and undergo metabolite-induced conformational changes, fluorogenic aptamers can exhibit poor folding, which limits their cellular fluorescence. To overcome this, we evolved a naturally occurring well-folded adenine riboswitch into a fluorogenic aptamer. We generated a library of roughly 1015 adenine aptamer-like RNAs in which the adenine-binding pocket was randomized for both size and sequence, and selected Squash, which binds and activates the fluorescence of green fluorescent protein-like fluorophores. Squash exhibits markedly improved in-cell folding and highly efficient metabolite-dependent folding when fused to a S-adenosylmethionine (SAM)-binding aptamer. A Squash-based ratiometric sensor achieved quantitative SAM measurements, revealed cell-to-cell heterogeneity in SAM levels and revealed metabolic origins of SAM. These studies show that the efficient folding of naturally occurring aptamers can be exploited to engineer well-folded cell-compatible fluorogenic aptamers and devices.

Effectiveness of ESPITO analgesia in enhancing recovery in patients undergoing open radical cystectomy when compared to a contemporaneous cohort receiving standard analgesia: an observational study.

OBJECTIVES: Bowel dysfunction is a major complication following open surgery for invasive cancer of the bladder that results in significant discomfort; complications and can prolong the length of stay. The incidence of postoperative ileus following open radical cystectomy has been reported as 23-40%. The median length of hospital stay after this surgery in the United Kingdom is 11 days. Standard analgesic techniques include wound infusion analgesia combined with systemic morphine or thoracic epidural analgsia. Combined erector spinae plane and intrathecal opioid analgesia is a novel technique that has been reported to be an effective method of providing perioperative analgesia thereby enhancing recovery after open radical cystectomy. METHODS: We performed a prospective study on the effectiveness of the novel analgesic technique (combined erector spinae plane and intrathecal opioid analgesia) in reducing the incidence of postoperative ileus, thereby facilitating early discharge following open radical cystectomy when compared to a contemporaneous control group receiving standard analgesia. Twenty-five patients received the novel analgesia while 31 patients received standard analgesia as a part of enhanced recovery programme. Standard analgesia arm included 14 patients who recived thoracic epidural analgesia (14/31, 45%) and 17 patients who received combined wound infusion analgesia and patient controlled analgesia with morphine (17/31, 55%). Primary outcome was the incidence of postoperative ileus. Secondary outcomes included length of hospital stay, tramadol consumption and time to bowel opening. RESULTS: Combined erector spinae plane and intrathecal opioid analgesia was associated with a reduced incidence of postoperative ileus (16 [4/25] vs. 65% [20/31], p<0.001), reduced time to first open bowel (4.4 ± 2.3 vs. 6.6 ± 2.3, p<0.001) and reduced median (IQR) length of hospital stay (7[6, 12] vs. 10[8, 15], p=0.007). There was no significant difference in rescue analgesia (intravenous tramadol) consumption. Complete avoidance of systemic morphine played a key role in improved outcomes. CONCLUSIONS: ESPITO was successful in reducing postoperative ileus and length of hospital stay after open radical cystectomy when compared to standard analgesia within an enhanced recovery programme.

Hepatorenal bypass resulting in dialysis independence in case of acute renal failure.

In the present case report, we have described a patient with bilateral renal artery occlusion resulting in the acute onset of refractory hypertension and renal failure requiring hemodialysis. Endovascular stenting of the renal arteries was not feasible owing to extensive aortic and renal orifice calcification. After consultation with nephrology and medical optimization, the patient underwent unilateral hepatorenal bypass, with subsequent improvement in renal function and sustained freedom from dialysis. Although percutaneous revascularization has become the preferred option for surgical management of renal artery occlusion, the findings from the present case have demonstrated that hepatorenal bypass remains a viable alternative for more complex cases.

Unique characteristics of the type B aortic dissection patients with malperfusion in the Vascular Quality Initiative.

OBJECTIVE: Type B aortic dissection (TBAD) complicated by malperfusion carries high morbidity and mortality. The present study was undertaken to compare the characteristics of malperfusion and uncomplicated cohorts and to evaluate the long-term differences in survival using a granular, national registry. METHODS: Patients with TBAD entered into the thoracic endovascular aortic repair/complex endovascular aortic repair module of the Vascular Quality Initiative from 2010 to 2019 were included. The demographic, radiographic, operative, postoperative, in-hospital, and long-term reintervention data were compared between the malperfusion and uncomplicated TBAD groups using t tests and χ2 analysis, as appropriate. Overall survival was compared using Cox regression to generate survival curves. RESULTS: Of the 2820 included patients, 2267 had uncomplicated TBAD and 553 had malperfusion. The patients with malperfusion were younger (age, 55.8 vs 61.2 years; P < .001), were more often male (79.7% vs 68.1%; P < .001), had a higher preoperative creatinine (1.8 vs 1.1 mg/dL; P < .001), had more often presented with an American Society of Anesthesiologists class of 4 or 5 (81.9% vs 58.4%; P < .001), and had more often presented with urgent status (77.4% vs 32.8%; P < .001). In contrast, the uncomplicated TBAD group had had more medical comorbidities, including coronary artery disease and chronic obstructive pulmonary disease, and a larger aortic diameter (4.0 cm vs 4.9 cm; P < .001). The malperfusion group more frequently had proximal zones of disease in zones 0 to 2 (38.6% vs 31.5%; P = .002) and distal zones of disease in zones 9 and above (78.7% vs 46.2%; P < .001), with a greater number of aortic zones traversed (7.7 vs 5.1; P < .001) and a greater frequency of dissection extension into branch vessels (61.8% vs 23.1%; P < .001). Patients with malperfusion also exhibited greater case complexity, with a greater need for branch vessel stenting and longer procedure times. The overall incidence of postoperative complications was greater in the malperfusion group (39.4% vs 17.1%; P < .001) and included a greater rate of spinal cord ischemia (6.3% vs 2.2%; P < .001), acute kidney injury (10.4% vs 0.9%; P < .001), and in-hospital mortality (11.6% vs 5.6%; P < .001). In-hospital reintervention was also greater for the malperfusion patients (14.5% vs 7.4%; P < .001), although the incidence of long-term reinterventions was similar between the two groups (8.7% vs 9.7%; P = .548). A proximal zone of disease in zone 0 to 2 was associated with decreased survival. In contrast, a distal zone of disease in 9 and above, in-hospital reintervention, and long-term follow-up were associated with increased survival. Despite these differences, long-term survival did not differ between the malperfusion and uncomplicated groups (P = .320.) CONCLUSIONS: Patients presenting with TBAD and malperfusion represent a unique cohort. Despite the greater need for branch vessel stenting and in-hospital reintervention, they had similar long-term reintervention rates and survival compared with those with uncomplicated TBAD. These data lend insight with regard to the observed differences between uncomplicated and malperfusion TBAD.

Effects of dual antiplatelet therapy on graft patency after lower extremity bypass.

OBJECTIVE: Current guidelines recommend single-agent antiplatelet therapy for patients with symptomatic peripheral artery disease and consideration of dual antiplatelet therapy (DAPT) after surgical revascularization. The objective of this study was both to explore prescribing patterns of single antiplatelet therapy vs DAPT after lower extremity bypass surgery and to investigate the effects of antiplatelet therapy on bypass graft patency. METHODS: A retrospective analysis of prospectively collected nonemergent infrainguinal lower extremity bypass operations entered in the national Vascular Quality Initiative (2003-2018) with captured long-term follow-up was performed. Patients discharged on aspirin monotherapy or DAPT were identified. Linear regression investigated temporal trends in antiplatelet use. Multivariable Cox regression investigated predictors of primary, primary assisted, and secondary patency. RESULTS: Of the 13,020 patients investigated, 52.2% were discharged on aspirin monotherapy and 47.8% on DAPT. The proportion of patients discharged on DAPT increased from 10.6% in 2003 to 60.6% in 2018 (P < .001). The DAPT cohort was younger, had higher rates of medical (hypertension, diabetes, congestive heart failure, chronic obstructive pulmonary disease) and atherosclerotic (coronary artery disease, prior coronary artery bypass graft or percutaneous coronary intervention, prior lower extremity intervention) comorbidities, and had higher risk bypass procedures (more distal targets, prior inflow bypass procedure, prosthetic conduit use). Multivariable Cox regression analysis did not show any difference between the DAPT and aspirin cohorts in primary patency (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.88-1.10; P = .78), primary assisted patency (HR, 0.93; 95% CI, 0.80-1.07; P = .30), or secondary patency (HR, 0.88; 95% CI, 0.74-1.06; P = .18). On subgroup analysis based on bypass conduit, DAPT was found to have a protective effect on patency only in the prosthetic bypass cohort (primary patency: HR, 0.81 [95% CI, 0.66-1.00; P = .05]; primary assisted patency: HR, 0.74 [95% CI, 0.58-0.94; P = .01]; and secondary patency: HR, 0.60 [95% CI, 0.44-0.82; P < .001]). No patency differences were observed on adjusted subgroup analysis for the other bypass conduits. CONCLUSIONS: A significant and increasing proportion of patients are discharged on DAPT after lower extremity bypass revascularization. These patients represent a higher risk cohort with more medical comorbidities and higher risk bypass features. After controlling for these differences, DAPT therapy had no beneficial effect on overall bypass graft patency or major adverse limb events. However, on subgroup analysis, DAPT was associated with improved bypass graft patency in patients receiving prosthetic bypass conduits. Further study is warranted to investigate optimal duration of DAPT therapy and its possible bleeding complications in prosthetic bypass patients.

Open Surgical Repair of Abdominal Aortic Aneurysms Maintains a Pivotal Role in the Endovascular Era.

Since the advent of endovascular aortic repair (EVAR) nearly three decades ago, there has been a paradigm shift in the treatment of the abdominal aortic aneurysm (AAA) to favor EVAR due to its reduced operative mortality, less invasive nature, and faster recovery times. However, more recently there has been an accumulation of data from large meta-analyses and randomized clinical trials revealing that EVAR has no survival benefit after approximately 2 years and is associated with substantially higher rates of reintervention and aneurysm rupture in the long term. These findings call into question the durability of EVAR compared with open aortic repair and emphasize the need for surgeons to remain competent with open aortic surgery in the modern era. This article will provide comprehensive review of a large body of literature comparing endovascular repair to open aortic surgery for the management of AAAs, and it will offer an overview of the open surgical repair technique for AAAs.