Systematic review of temporary intravascular shunt use in military and civilian extremity trauma.

BACKGROUND: The use of temporary intravascular shunts (TIVS) in the setting of military and civilian trauma has grown in recent years, predominantly because of the mounting evidence of improved limb outcomes. We sought to characterize the use and outcomes of TIVS in trauma through a systematic review of military and civilian literature. METHODS: The MEDLINE, EBSCO, EMBASE, and Cochrane databases were searched for studies on TIVS use in military and civilian trauma settings published between January 2000 and March 2021. Reports lacking systematic data collection along with those with insufficient TIVS descriptive and outcome data were excluded. Data regarding the characteristics and outcomes of TIVS were assessed and collective syntheses of military and civilian data performed. RESULTS: Twenty-one reports were included, 14 from civilian trauma centers or databases and 7 from military field data or databases (total of 1,380 shunts in 1,280 patients). Sixteen were retrospective cohort studies, and four were prospective. Five studies had an unshunted comparison group. Shunts were predominantly used in the lower extremity and most commonly for damage control indications. Dwell times were infrequently reported and were not consistently linked to shunt thrombosis or other complications. Anticoagulation during shunting was sparsely reported and inconsistently applied. Shunted limbs had higher injury severity than unshunted limbs but similar salvage rates. CONCLUSION: Temporary intravascular shunts are effective for expeditious restoration of perfusion in severely injured limbs and likely contribute to limb salvage. There is a paucity of comparative TIVS data in the literature and no consistently applied reporting standards, so controversies regarding TIVS use remain. LEVEL OF EVIDENCE: Systematic Review, level IV.

Portal vein reconstruction with cryopreserved vascular grafts: A two-edged sword.

BACKGROUND: Portal vein anastomotic complications related to size discrepancy are important causes of morbidity and mortality in pediatric liver transplantation. Interposed vascular grafts in portal vein anastomosis can solve this problem. The aim of this study is to evaluate the results of pediatric liver transplantations performed using cryopreserved interposed vascular grafts between graft portal vein and superior mesenteric vein (SMV)-splenic vein (SpV) confluence. METHODS: Twenty-nine pediatric patients received liver transplantation using cryopreserved venous grafts in our Liver Transplant Institute between 2013 and 2020 were included in this study. Demographic, clinical, and operative characteristics and postoperative follow-up were analyzed. RESULTS: Sixteen patients (55.2%) had portal hypoplasia and five patients (17.2%) had portal vein thrombosis. In total, six patients (20.6%) suffered portal vein thrombosis in the early postoperative period. Three patients (10.3%) experienced portal vein thrombosis in the late postoperative period. Late portal vein thrombosis rate was significantly higher in patients with early portal vein thrombosis (3/6 patients [50%] versus 0/23 patients [0%]; p = .034). Lack of portal flow was significantly higher in patients with both early (50% versus 0%; p = .002) and late portal vein thrombosis (66.7% versus 6.7%; p = .03). CONCLUSION: Preoperative portal vein thrombosis and insufficient flow are important factors affecting success of liver transplant in children. The use of interposed vein grafts in problematic portal anastomoses can overcome portal flow problems.

Long-term results of ulnar and radial reconstruction with interpositional grafting using the deep inferior epigastric artery for chronic hand ischemia.

Chronic hand ischemia causes cold intolerance, intractable pain, and digital ulceration. If ischemic symptoms persist despite pharmacologic treatments, surgical interventions should be considered. This retrospective study evaluated the long-term results after ulnar and radial reconstruction using an interpositional deep inferior epigastric artery (DIEA) graft combined with periarterial sympathectomy. Patients who underwent this surgery from March 2003 to February 2019 were included. To evaluate variables influencing recurrence after the procedure, patients were divided into the recurred and non-recurred groups and their data were compared. Overall, 62 cases involving 47 patients were analyzed (16 and 46 cases in the recurred and non-recurred groups, respectively). The median DIEA graft length was 8.5 cm. The rates of rheumatic disease and female patients were significantly higher in the recurred than in the non-recurred group, without significant between-group differences in postoperative complication rates. In the multivariate analysis, underlying rheumatic disease and graft length had significant effects on recurrence. In Kaplan-Meier analysis, the 5- and 10-year symptom-free rates were 81.3% and 68.0%, respectively, with lower rates for cases with rheumatic disease. Thus, arterial reconstruction using an interpositional DIEA graft provides long-term sustainable vascular supply in patients with chronic hand ischemia, especially in those without rheumatic disease.

Cell Viability Assessment Using Fluorescence Vital Dyes and Confocal Microscopy in Evaluating Freezing and Thawing Protocols Used in Cryopreservation of Allogeneic Venous Grafts.

The authors present their contribution to the improvement of methods suitable for the detection of the freezing and thawing damage of cells of cryopreserved venous grafts used for lower limb revascularization procedures. They studied the post-thaw viability of cells of the wall of cryopreserved venous grafts (CVG) immediately after thawing and after 24 and 48 h culture at +37 °C in two groups of six CVG selected randomly for slow thawing in the refrigerator and rapid thawing in a water bath at +37 °C. The grafts were collected from multi-organ and tissue brain-dead donors, cryopreserved, and stored in a liquid nitrogen vapor phase for five years. The viability was assessed from tissue slices obtained by perpendicular and longitudinal cuts of the thawed graft samples using in situ staining with fluorescence vital dyes. The mean and median immediate post-thaw viability values above 70% were found in using both thawing protocols and both types of cutting. The statistically significant decline in viability after the 48-h culture was observed only when using the slow thawing protocol and perpendicular cutting. The possible explanation might be the "solution effect damage" during slow thawing, which caused a gentle reduction in the graft cellularity. The possible influence of this phenomenon on the immunogenicity of CVG should be the subject of further investigations.

Zoledronate alters natural progression of tissue-engineered vascular grafts.

Macrophages are a critical driver of neovessel formation in tissue-engineered vascular grafts (TEVGs), but also contribute to graft stenosis, a leading clinical trial complication. Macrophage depletion via liposomal delivery of clodronate, a first-generation bisphosphonate, mitigates stenosis, but simultaneously leads to a complete lack of tissue development in TEVGs. This result and the associated difficulty of utilizing liposomal delivery means that clodronate may not be an ideal means of preventing graft stenosis. Newer generation bisphosphonates, such as zoledronate, may have differential effects on graft development with more facile drug delivery. We sought to examine the effect of zoledronate on TEVG neotissue formation and its potential application for mitigating TEVG stenosis. Thus, mice implanted with TEVGs received zoledronate or no treatment and were monitored by serial ultrasound for graft dilation and stenosis. After two weeks, TEVGs were explanted for histological examination. The overall graft area and remaining graft material (polyglycolic-acid) were higher in the zoledronate treatment group. These effects were associated with a corresponding decrease in macrophage infiltration. In addition, zoledronate affected the deposition of collagen in TEVGs, specifically, total and mature collagen. These differences may be, in part, explained by a depletion of leukocytes within the bone marrow that subsequently led to a decrease in the number of tissue-infiltrating macrophages. TEVGs from zoledronate-treated mice demonstrated a significantly greater degree of smooth muscle cell presence. There was no statistical difference in graft patency between treatment and control groups. While zoledronate led to a decrease in the number of macrophages in the TEVGs, the severity of stenosis appears to have increased significantly. Zoledronate treatment demonstrates that the process of smooth muscle cell-mediated neointimal hyperplasia may occur separately from a macrophage-mediated mechanism.

Long-term outcome in pediatric surgical bypass grafting after traumatic injury and tumor resection: retrospective cohort analysis.

Vascular bypass surgery in children differs significantly from adults. It is a rarely performed procedure in the setting of trauma and tumor surgery. Besides technical challenges to reconstruct the small and spastic vessels, another concern in bypass grafting is the adequate limb length growth over time. The primary aim of this study was to assess long-term outcome after pediatric bypass grafting, in a single academic center, focusing on potential effects on limb development. In this retrospective cohort analyses we included all pediatric patients undergoing vascular bypass grafting at our department between 2002 and 2017. All patients ≤ 18 years suffered a traumatic injury or underwent a tumor resection of the lower or upper limb. The youngest female patient was 0.4 years, the youngest male patient was 3.5 years. During the observation period, 33 pediatric patients underwent vascular repair, whereby 15 patients underwent bypass grafting. Median overall follow-up was 4.7 years (IQR ± 9). 8 patients (53%) had a traumatic injury (traumatic surgery group) and 7 patients had a planned orthopedic tumor resection (orthopedic surgery group). In 13/15 (87%) a great saphenous vein (GSV) graft and in 2/15 (13%) a Gore-Tex graft was used for bypassing. Both Gore-Tex grafts showed complete occlusion 12 and 16 years after implantation. No patient died in the early postoperative phase (< 30 days), however 3/7 (43%) in the orthopedic group died during follow-up. Revision surgery had to be performed in 1/15 (7%) patients. A functional use of the extremity was reported in all patients. Normal limb length growth according to the contralateral site, and therefore bypass growth, could be documented in 14/15 patients. Children are surgically challenging. In our study, surgery by a specialized vascular surgery team using GSV grafts led to adequate limb length and bypass growth, and we observed no functional restrictions.

Lesion Trapping with High-Flow Bypass for Ruptured Internal Carotid Artery Blood Blister-Like Aneurysm Has Little Impact on the Anterior Choroidal Artery Flow: Case Series and Literature Review.

OBJECTIVE: To examine the relationship between trap location and cerebral infarction in the anterior choroidal artery (AChA) region and associated risks in ruptured internal carotid artery blood blister-like aneurysm (BLA) treatment with high-flow bypass and lesion trapping. METHODS: We included 26 patients diagnosed with BLAs and treated with high-flow bypass and trapping. We examined clinical characteristics including age, aneurysm trap location, final prognosis, cerebral infarction on postoperative magnetic resonance imaging, and modified Rankin Scale score at discharge. We also searched the literature for similar studies. RESULTS: The modified Rankin Scale score at discharge was 0-2 in 20 patients, 3-5 in 2 patients, and 6 in 2 patients. In 19/26 patients (73.1%), the trapped segment was between the posterior communicating (PcomA) and the ophthalmic arteries. In 2 patients (7.7%), the trapped segment included the PcomA and the AChA; in 4 patients (15.4%), the trapped segment was within the PcomA. In these patients, the PcomA was occluded, and blood from the high-flow bypass flowed out to the AChA alone. No patient showed cerebral infarction. Our systematic review identified 70 patients. Of all 96 patients, 12 had AChA cerebral infarction; however, the infarction affected the prognosis of only 2 patients. CONCLUSIONS: When treating BLAs with high-flow bypass and lesion trapping, the frequency of AChA cerebral infarction is low even when the PcomA is occluded, leaving the AChA as the only outflow vessel during high-flow bypass. However, PcomA occlusion may be associated with risks when treating patients with advanced arteriosclerosis near C1-2.

Saphenous vein valve assessment utilizing upright CT to potentially improve graft assessment for bypass surgery.

Saphenous veins (SVs) are frequently employed as bypass grafts. The SV graft failure is predominantly seen at the valve site. Avoiding valves during vein harvest would help reduce graft failure. We endeavored to detect SV valves, tributaries, and vessel size employing upright computed tomography (CT) for the raw cadaver venous samples and in healthy volunteers. Five cadaver legs were scanned. Anatomical analysis showed 3.0 (IQR: 2.0-3.0) valves and 13.50 (IQR: 10.00-16.25) tributaries. The upright CT completely detected, compared to 2.0 (IQR: 1.5-2.5, p = 0.06) valves and 9.5 (IQR: 7.5-13.0, p = 0.13) tributaries by supine CT. From a total of 190 volunteers, 138 (men:75, women:63) were included. The number of valves from the SF junction to 35 cm were significantly higher in upright CT than in supine CT bilaterally [upright vs. supine, Right: 4 (IQR: 3-5) vs. 2 (IQR:1-2), p < 0.0001, Left: 4 (IQR: 3-5) vs. 2 (IQR: 1-2), p < 0.0001]. The number of tributaries and vessel areas per leg were also higher for upright compared with supine CT. Upright CT enables non-invasive detection of SV valves, tributaries, and vessel size. Although not tested here, it is expected that upright CT may potentially improve graft assessment for bypass surgery.

Reconstructing spleno-mesenterico-portal cofluence by bifurcated allogeneic vein in local advanced pancreatic cancer-a feasible method to avoid left-sided portal hypertension.

BACKGROUND: Left-sided portal hypertension is usually found in patients undergoing pancreaticoduodenectomy (PD) with spleno-mesenterico-portal (S-M-P) confluence resection. This study is to explore the outcomes of S-M-P confluence reconstruction after resection by using bifurcated allogeneic vein. METHODS: Clinicopathologic data of patients who underwent extensive PD with S-M-P confluence resection for carcinoma of pancreatic head/uncinate process in our hospital between December 2011 and August 2018 were retrospectively reviewed and clinical outcomes of vein reconstruction after resection were analyzed. RESULTS: Of the 37 patients enrolled, S-M-P reconstruction by bifurcated allogeneic vein was performed in 24 cases (group 1) and simply splenic vein ligation in 13 cases (group 2). Items including pathological results, blood loss, and complications were comparable between the two groups, operation time was longer in group 1 (573.8 vs. 479.2 min, p = 0.018). Significantly decreased platelet count (205.9 vs. 133.1 × 109 /L, p = 0.001) and increased splenic volume (270.9 vs. 452.2 ml, p < 0.001) were observed in group 2 at 6 months after operation. The mean splenic hypertrophy ratio was 1.06 in group 1 and 1.63 in group 2, respectively (p < 0.001). There were four patients with varices were found in group 2, none in group 1. CONCLUSIONS: Without increased complications, reconstructing S-M-P confluence by bifurcated allogeneic vein after resection may help to avoid left-sided portal hypertension.

European registry of type A aortic dissection (ERTAAD) - rationale, design and definition criteria.

BACKGROUND: Acute Stanford type A aortic dissection (TAAD) is a life-threatening condition. Surgery is usually performed as a salvage procedure and is associated with significant postoperative early mortality and morbidity. Understanding the patient's conditions and treatment strategies which are associated with these adverse events is essential for an appropriate management of acute TAAD. METHODS: Nineteen centers of cardiac surgery from seven European countries have collaborated to create a multicentre observational registry (ERTAAD), which will enroll consecutive patients who underwent surgery for acute TAAD from January 2005 to March 2021. Analysis of the impact of patient's comorbidities, conditions at referral, surgical strategies and perioperative treatment on the early and late adverse events will be performed. The investigators have developed a classification of the urgency of the procedure based on the severity of preoperative hemodynamic conditions and malperfusion secondary to acute TAAD. The primary clinical outcomes will be in-hospital mortality, late mortality and reoperations on the aorta. Secondary outcomes will be stroke, acute kidney injury, surgical site infection, reoperation for bleeding, blood transfusion and length of stay in the intensive care unit. DISCUSSION: The analysis of this multicentre registry will allow conclusive results on the prognostic importance of critical preoperative conditions and the value of different treatment strategies to reduce the risk of early adverse events after surgery for acute TAAD. This registry is expected to provide insights into the long-term durability of different strategies of surgical repair for TAAD. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04831073 .

Case report: a novel approach for the emergency repair of acute aortic rupture associated with congenital aortic Coarctation.

BACKGROUND: Congenital aortic coarctation (CoA) associated with aortic rupture is a rare but extremely lethal condition. In pregnant patients, the condition becomes very risky. CASE PRESENTATION: We presented a case of a pregnant (20 weeks gestation) patient with CoA associated with ruptured aortic pseudoaneurysm who was successfully rescued using a novel hybrid strategy. CONCLUSIONS: This hybrid approach may be a life-saving bridging intervention in patients with CoA associated with devastating complications, such as ruptured aneurysms, especially with extremely narrowed access.

Bilateral brachial artery infiltration by tumoral calcinosis: A case report.

We, herein, presented a rare case of bilateral brachial artery infiltration by tumoral calcinosis located on both elbows. A 58-yearold man presented with a history of painless, palpable solid mass restricting the range of motion of both elbows. These masses were located on the anterior aspect of the elbows and gradually enlarged. After clinical, laboratory and radiological examinations, tumoral calcinosis was suspected, and excisional biopsy was planned for a definite diagnosis. Surgery was first performed on the left elbow. The median nerve was found to be compressed but not infiltrated by the mass. Interestingly, the brachial artery was totally infiltrated throughout the entire mass. Occlusion was observed in the brachial artery located within the mass. The tumor on the left elbow, 8.5 × 5.5 × 2.5 cm in size, was totally excised with approximately 12-cm brachial artery segment. The artery was resected until the healthy tissue was reached. The defect was reconstructed with saphenous vein graft obtained from the ipsilateral lower extremity. The same surgical procedure was performed on the right elbow after 3 months. The tumor size on the right elbow was 7 × 3.5 × 1.7 cm. Approximately 15-cm brachial artery segment was excised, and the defect was reconstructed with saphenous vein graft. Tumoral calcinosis is a rare benign condition that can be located in close relationship with neurovascular structures. In such cases, detailed neurologic and vascular examination, including imaging modalities, for arterial flow is essential to establish a more accurate surgical plan and avoid any unexpected situation during surgery.

Use of paclitaxel carried in lipid nanoparticles to treat aortic allograft transplantation in rats.

OBJECTIVES: The aim of this study was to test whether lipid core nanoparticles loaded with paclitaxel (LDE-PTX) protect rat aortic allograft from immunological damage. METHODS: Fisher and Lewis rats were used differing in minor histocompatibility loci. Sixteen Lewis rats were allocated to four-animal groups: SYNG (syngeneic), Lewis rats receiving aorta grafts from Lewis rats; ALLO (allogeneic), Lewis rats receiving aortas from Fisher rats; ALLO+LDE (allogeneic transplant treated with LDE), Lewis rats receiving aortas from Fisher rats, treated with LDE (weekly injection for 3 weeks); ALLO+LDE-PTX (allogeneic transplant treated with LDE-PTX), Lewis rats receiving aortas from Fisher rats treated with LDE-PTX (4 mg/kg weekly for 3 weeks). Treatments began on transplantation day. RESULTS: Thirty days post-transplantation, SYNG showed intact aortas. ALLO and ALLO+LDE presented intense neointimal formation. In ALLO+LDE-PTX, treatment inhibited neointimal formation; narrowing of aortic lumen was prevented in ALLO and ALLO+LDE. LDE-PTX strongly inhibited proliferation and intimal invasion by smooth muscle cells, diminished 4-fold presence of apoptotic/dead cells in the intima, reduced the invasion of aorta by macrophages and T-cells and gene expression of pro-inflammatory tumour necrosis factor-alpha (TNFα), interferon gamma (IFNγ) and interleukin-1 beta (IL-1ß). CONCLUSIONS: LDE-PTX was effective in preventing the vasculopathy associated with rejection and may offer a potent therapeutic tool for post-transplantation.

A modified technique for performing proximal anastomosis of a supracoronary graft.

An aortic aneurysm may cause loss of the sinotubular junction. Reduction in the diameter of the sinotubular junction may reestablish aortic valve competence in patients with an ascending aortic aneurysm and aortic valve regurgitation with normal aortic cusps. With this video tutorial we describe an alternative technique for replacing the ascending aorta with restoration of the sinotubular junction.

Systems Approach to Discovery of Therapeutic Targets for Vein Graft Disease: PPARα Pivotally Regulates Metabolism, Activation, and Heterogeneity of Macrophages and Lesion Development.

BACKGROUND: Vein graft failure remains a common clinical challenge. We applied a systems approach in mouse experiments to discover therapeutic targets for vein graft failure. METHODS: Global proteomics and high-dimensional clustering on multiple vein graft tissues were used to identify potential pathogenic mechanisms. The PPARs (peroxisome proliferator-activated receptors) pathway served as an example to substantiate our discovery platform. In vivo mouse experiments with macrophage-targeted PPARα small interfering RNA, or the novel, selective activator pemafibrate demonstrate the role of PPARα in the development and inflammation of vein graft lesions. In vitro experiments further included metabolomic profiling, quantitative polymerase chain reaction, flow cytometry, metabolic assays, and single-cell RNA sequencing on primary human and mouse macrophages. RESULTS: We identified changes in the vein graft proteome associated with immune responses, lipid metabolism regulated by the PPARs, fatty acid metabolism, matrix remodeling, and hematopoietic cell mobilization. PPARα agonism by pemafibrate retarded the development and inflammation of vein graft lesions in mice, whereas gene silencing worsened plaque formation. Pemafibrate also suppressed arteriovenous fistula lesion development. Metabolomics/lipidomics, functional metabolic assays, and single-cell analysis of cultured human macrophages revealed that PPARα modulates macrophage glycolysis, citrate metabolism, mitochondrial membrane sphingolipid metabolism, and heterogeneity. CONCLUSIONS: This study explored potential drivers of vein graft inflammation and identified PPARα as a novel potential pharmacological treatment for this unmet medical need.