Assessment of changes in vessel area during needle manipulation in microvascular anastomosis using a deep learning-based semantic segmentation algorithm: A pilot study.

Appropriate needle manipulation to avoid abrupt deformation of fragile vessels is a critical determinant of the success of microvascular anastomosis. However, no study has yet evaluated the area changes in surgical objects using surgical videos. The present study therefore aimed to develop a deep learning-based semantic segmentation algorithm to assess the area change of vessels during microvascular anastomosis for objective surgical skill assessment with regard to the "respect for tissue." The semantic segmentation algorithm was trained based on a ResNet-50 network using microvascular end-to-side anastomosis training videos with artificial blood vessels. Using the created model, video parameters during a single stitch completion task, including the coefficient of variation of vessel area (CV-VA), relative change in vessel area per unit time (ΔVA), and the number of tissue deformation errors (TDE), as defined by a ΔVA threshold, were compared between expert and novice surgeons. A high validation accuracy (99.1%) and Intersection over Union (0.93) were obtained for the auto-segmentation model. During the single-stitch task, the expert surgeons displayed lower values of CV-VA (p < 0.05) and ΔVA (p < 0.05). Additionally, experts committed significantly fewer TDEs than novices (p < 0.05), and completed the task in a shorter time (p < 0.01). Receiver operating curve analyses indicated relatively strong discriminative capabilities for each video parameter and task completion time, while the combined use of the task completion time and video parameters demonstrated complete discriminative power between experts and novices. In conclusion, the assessment of changes in the vessel area during microvascular anastomosis using a deep learning-based semantic segmentation algorithm is presented as a novel concept for evaluating microsurgical performance. This will be useful in future computer-aided devices to enhance surgical education and patient safety.

A short report on the current landscape of Artificial Intelligence (AI) in vascular surgery in Pakistan.

This study focuses on the current applications, potential, and challenges to Artificial Intelligence (AI) integration in vascular surgery with specific emphasis on its relevance in Pakistan. Despite the benefits of AI in vascular surgery, there is a substantial gap in its adoption in Pakistan compared to global standards. In our context with limited resources and a scarcity of vascular surgeons, AI can serve as a promising solution. It can enhance healthcare accessibility, improve diagnostic accuracy, and alleviate the workload on vascular surgeons. However, hurdles including the absence of a comprehensive vascular surgery database, a shortage of AI experts, and potential algorithmic biases pose significant challenges to AI implementation. Despite these obstacles, the study underscores the imperative for continued research, collaborative efforts, and investments to unlock the full potential of AI and elevate vascular healthcare standards in Pakistan.

Comment on Rehman et al. "Short-Term Outcomes of Elective Abdominal Aortic Aneurysm Repair".

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[Perfusion Methods and Reconstruction Techniques for Performing Aortic Arch Surgery with Isolated Left Vertebral Artery].

In our institution, when we perform aortic arch surgery with isolated left vertebral artery using an extracorporeal circulation, we select an interposed saphenous vein graft technique. This technique has a relatively short clamping time and allows for selective cerebral perfusion and flexible choice of reconstruction site. Although other techniques, such as an island reconstruction, have been reported, we do not perform it often due to its longer ischemic time of the left vertebral artery. On the other hand, we use a direct reconstruction technique in cases where an extracorporeal circulation is not used. This direct reconstruction technique in cases of isolated left vertebral artery could reduce the time and number of clamping it.

Effect of lidocaine on intraoperative blood pressure variability in patients undergoing major vascular surgery.

BACKGROUND: Dynamic fluctuations of arterial blood pressure known as blood pressure variability (BPV) may have short and long-term undesirable consequences. During surgical procedures blood pressure is usually measured in equal intervals allowing to assess its intraoperative variability, which significance for peri and post-operative period is still under debate. Lidocaine has positive cardiovascular effects, which may go beyond its antiarrhythmic activity. The aim of the study was to verify whether the use of intravenous lidocaine may affect intraoperative BPV in patients undergoing major vascular procedures. METHODS: We performed a post-hoc analysis of the data collected during the previous randomized clinical trial by Gajniak et al. In the original study patients undergoing elective abdominal aorta and/or iliac arteries open surgery were randomized into two groups to receive intravenous infusion of 1% lidocaine or placebo at the same infusion rate based on ideal body weight, in concomitance with general anesthesia. We analyzed systolic (SBP), diastolic (DBP) and mean arterial blood (MAP) pressure recorded in 5-minute intervals (from the first measurement before induction of general anaesthesia until the last after emergence from anaesthesia). Blood pressure variability was then calculated for SBP and MAP, and expressed as: standard deviation (SD), coefficient of variation (CV), average real variability (ARV) and coefficient of hemodynamic stability (C10%), and compared between both groups. RESULTS: All calculated indexes were comparable between groups. In the lidocaine and placebo groups systolic blood pressure SD, CV, AVR and C10% were 20.17 vs. 19.28, 16.40 vs. 15.64, 14.74 vs. 14.08 and 0.45 vs. 0.45 respectively. No differences were observed regarding type of surgery, operating and anaesthetic time, administration of vasoactive agents and intravenous fluids, including blood products. CONCLUSION: In high-risk vascular surgery performed under general anesthesia, lidocaine infusion had no effect on arterial blood pressure variability. TRIAL REGISTRATION: ClinicalTrials.gov; NCT04691726 post-hoc analysis; date of registration 31/12/2020.

[Preventive myocardial revascularization prior to abdominal aortic repair in patients without cardiac symptoms: long-term results]. / Profilakticheskaya revaskulyarizatsiya miokarda pered rezektsiei anevrizmy bryushnoi aorty u kardiologicheski asimptomnykh bol'nykh: otdalennye rezul'taty.

OBJECTIVE: To evaluate the long-term influence of preoperative invasive coronary screening and preventive myocardial revascularization on mortality and cardiac complications after open surgery for abdominal aortic aneurysms (AAA). MATERIAL AND METHODS: We present long-term outcomes after open surgery for AAA between 2011 and 2022. Patients without clinical or objective signs of coronary artery disease were included. In the 1st group, routine coronary angiography was performed before surgery. Prophylactic myocardial revascularization was performed in 12 cases. Long-term data on 45 patients were obtained. In the 2nd group, 53 patients underwent repair without invasive coronary screening, and data on 48 patients were obtained in this group. RESULTS: The median follow-up was 32 and 79 months, respectively. Kaplan-Meyer overall 48-month survival was 87.3% and 82.1%, respectively (p=0.278). In the first group, 2 patients developed angina pectoris in the same period. In the second group, we observed 2 cases of myocardial infarction and 3 cases of angina pectoris without infarction. Analysis of survival curves found no significant differences (p=0.165). CONCLUSION: In our study, invasive coronary screening and preventive myocardial revascularization in patients without clinical and objective signs of coronary artery did not improve 4-year long-term period after abdominal aortic repair. Perhaps, differences will appear after 4 years, and this requires further follow-up after coronary angiography. However, there is a tendency towards more common onsets of coronary artery disease that dictates the need for cardiac monitoring of such patients.

The Utility of Prevena Negative Pressure Wound Therapy on Groin Incisions for Critical Limb-Threatening Ischemia: A Single Institution Experience.

BACKGROUND: Incisional negative pressure wound therapy (iNPWT) is an adjunctive treatment that uses constant negative pressure suction to facilitate healing. The utility of this treatment modality on vascular operations for critical limb-threatening ischemia (CLTI) has yet to be elucidated. This study compares the incidence of postoperative wound complications between the Prevena Incision Management System, a type of iNPWT, and standard wound dressings for vascular patients who also underwent plastic surgery closure of groin incisions for CLTI. METHOD: We performed a retrospective cohort study of 40 patients with CLTI who underwent 53 open vascular surgeries with subsequent sartorius muscle flap closure. Patient demographics, intraoperative details, and wound complications were measured from 2015 to 2018 at the University of California San Francisco. Two cohorts were generated based on the modality of postoperative wound management and compared on wound healing outcomes. RESULTS: Of the 53 groin incisions, 29 were managed with standard dressings, and 24 received iNPWT. Patient demographics, comorbidities, and operative characteristics were similar between the 2 groups. Patients who received iNPWT had a significantly lower rate of infection (8.33% vs 31.0%, P = 0.04) and dehiscence (0% vs 41.3%, P < 0.01). Furthermore, the iNPWT group had a significantly lower rate of reoperation (0% vs 17.2%, P = 0.03) for wound complications within 30 days compared with the control group and a moderately reduced rate of readmission (4.17% vs 20.7%, P = 0.08). CONCLUSIONS: Rates of infection, reoperation, and dehiscence were significantly reduced in patients whose groin incisions were managed with iNPWT compared with standard wound care. Readmission rates were also decreased, but this difference was not statistically significant. Our results suggest that implementing iNPWT for the management of groin incisions, particularly in patients undergoing vascular operations for CLTI, may significantly improve clinical outcomes.

Late Outcomes of Surgery Versus Medical Therapy in Patients With Type A Aortic Intramural Hematoma: Meta-Analysis of Reconstructed Time-to-Event Data.

The effect of an initial surgical approach (in comparison with initial medical therapy) in acute type A intramural hematoma remains insufficiently explored. We designed a pooled analysis of Kaplan-Meier-derived individual patient data from studies with follow-up for overall survival (all-cause death). Restricted mean survival time was calculated to evaluate lifetime gain or loss. The Risk of Bias in Non-Randomized Studies of Interventions tool (ROBINS-I) was used to assess risk of bias. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) was applied to assess certainty of evidence. Eight studies met our eligibility criteria, including a total of 654 patients (311 patients treated with surgery and 343 patients treated with medical therapy alone). All the studies were non-randomized and observational. The median follow-up was 4.6 years (interquartile range 1.0 to 7.7). Patients who underwent surgery had a significantly lower risk of mortality compared with patients receiving medical therapy alone (hazard ratio 0.51, 95% confidence interval 0.35 to 0.74, p <0.001). The restricted mean survival time was overall 1.1 years greater with surgery compared with medical therapy, and this difference was statistically significant (p <0.001), which means that surgery is associated with lifetime gain. The overall risk of bias (ROBINS-I) was considered moderate-to-serious and the certainty of evidence (GRADE) was deemed to be low. In conclusion, in the overall follow-up, surgery as the initial approach was associated with better late survival and lifetime gain in comparison with medical therapy alone in the setting of acute type A aortic intramural hematoma; however, high-quality randomized trials are warranted to establish the efficacy of the surgical strategy.

3D printing: a useful tool for safe clinical practice in children with complex vasculature.

BACKGROUND: 3D printing has been used in different medical contexts, although it is underutilised in paediatrics. We present the first use of 3D printing in the management of three paediatric patients with complex renovascular disease. METHODS: Patient-specific 3D models were produced from conventional 2D imaging and manufactured using 3D polyjet printing technology. All three patients had different underlying pathologies, but all underwent multiple endovascular interventions (renal artery balloon angioplasty) prior to 3D printing and subsequent vascular surgery. The models were verified by an expert radiologist and then presented to the multidisciplinary team to aid with surgical planning. RESULTS: Following evaluation of the 3D-printed models, all patients underwent successful uni/bilateral renal auto-transplants and aortic bypass surgery. The 3D models allowed more detailed preoperative discussions and more focused planning of surgical approach, therefore enhancing safer surgical planning. It influenced clinical decision-making and shortened general anaesthetic time. The families and the patients reported that they had a significantly improved understanding of the patient's condition and had more confidence in understanding proposed surgical intervention, thereby contributing to obtaining good-quality informed consent. CONCLUSION: 3D printing has a great potential to improve both surgical safety and decision-making as well as patient understanding in the field of paediatrics and may be considered in wider surgical areas.

Systematic review and meta-analysis of endovascular therapy versus open surgical repair for the traumatic lower extremity arterial injury.

OBJECTIVE: For traumatic lower extremity artery injury, it is unclear whether it is better to perform endovascular therapy (ET) or open surgical repair (OSR). This study aimed to compare the clinical outcomes of ET versus OSR for traumatic lower extremity artery injury. METHODS: The Medline, Embase, and Cochrane Databases were searched for studies. Cohort studies and case series reporting outcomes of ET or OSR were eligible for inclusion. Robins-I tool and an 18-item tool were used to assess the risk of bias. The primary outcome was amputation. The secondary outcomes included fasciotomy or compartment syndrome, mortality, length of stay and lower extremity nerve injury. We used the random effects model to calculate pooled estimates. RESULTS: A total of 32 studies with low or moderate risk of bias were included in the meta-analysis. The results showed that patients who underwent ET had a significantly decreased risk of major amputation (OR = 0.42, 95% CI 0.21-0.85; I2=34%) and fasciotomy or compartment syndrome (OR = 0.31, 95% CI 0.20-0.50, I2 = 14%) than patients who underwent OSR. No significant difference was observed between the two groups regarding all-cause mortality (OR = 1.11, 95% CI 0.75-1.64, I2 = 31%). Patients with ET repair had a shorter length of stay than patients with OSR repair (MD=-5.06, 95% CI -6.76 to -3.36, I2 = 65%). Intraoperative nerve injury was just reported in OSR patients with a pooled incidence of 15% (95% CI 6%-27%). CONCLUSION: Endovascular therapy may represent a better choice for patients with traumatic lower extremity arterial injury, because it can provide lower risks of amputation, fasciotomy or compartment syndrome, and nerve injury, as well as shorter length of stay.

The open abdomen in mesenteric ischemia: A tool for patients undergoing revascularization.

BACKGROUND: We examined outcomes in Acute Mesenteric Ischemia (AMI) with the hypothesis that Open Abdomen (OA) is associated with decreased mortality. METHODS: We performed a cohort study reviewing NSQIP emergency laparotomy patients, 2016-2020, with a postoperative diagnosis of mesenteric ischemia. OA was defined using flags for patients without fascial closure. Logistic regression was used with outcomes of 30-day mortality and several secondary outcomes. RESULTS: Out of 5514 cases, 4624 (83.9%) underwent resection and 387 (7.0%) underwent revascularization. The OA rate was 32.6%. 10.8% of patients who were closed required reoperation. After adjustment for demographics, transfer status, comorbidities, preoperative variables including creatinine, white blood cell count, and anemia, as well as operative time, OA was associated with OR 1.58 for mortality (95% CI [1.38, 1.81], p < 0.001). Among revascularizations, there was no such association (p = 0.528). OA was associated with ventilator support >48 h (OR 4.04, 95% CI [3.55, 4.62], and p < 0.001). CONCLUSION: OA in AMI was associated with increased mortality and prolonged ventilation. This is not so in revascularization patients, and 1 in 10 patients who underwent primary closure required reoperation. OA should be considered in specific cases of AMI. LEVEL OF EVIDENCE: Retrospective cohort, Level III.

Pre-selection blade size choice for the microsurgical clipping of cerebral artery aneurysms: A numerical study.

BACKGROUND: Brain strokes comprise the third leading cause of death worldwide. Microsurgical clipping is recognized as being one of the most effective approaches to the treatment of brain aneurysms. The incomplete closure of the distal-side aneurysm neck is the most common cause of the persistent filling of the dome. Since the diameter of the neck increases when the neck of the aneurysm is squeezed closed by the blades of the clip, the blades should be correspondingly longer. This study provided an assessment of whether the presurgical selection of clips using a 3D planning system is feasible in terms of selecting the most suitable clip for aneurysm occlusion. METHODS: The computational model was created based on computer tomography data obtained from nine brain aneurysms. The closing of the aneurysm was provided in two steps. The first the length of the blades used for closing corresponded to the length of the aneurysm neck as confirmed by the radiological measurements. The second the length of the blades was adjusted according to stage one, so as to determine the minimum required for the closure of all the gaps in the interior space of the aneurysm neck. RESULTS: No differences were detected between the radiological measurement of the aneurysm neck size and the measurements obtained from the reconstructed stereolithographic 3D models. It was observed that the size of the aneurysm neck increased following clipping by 40% to 60% of its original size. The larger the aneurysm neck, the greater the deformation of the aneurysm. CONCLUSION: Firstly, the 3D reconstruction of CT/MRI data did not result in any loss of accuracy and the measurement of the neck of the aneurysm was the same for both of the methods employed. The second, and more important, outcome was that the deformation of the neck of the cerebral aneurysm is at least 1.4x greater than its original size. This information is essential in terms of the pre-selection of the size of the clip.

Perioperative hyperoxia- impact on myocardial biomarkers, strain and outcome in high-risk patients undergoing non-cardiac surgery: Protocol for a prospective randomized controlled trial.

BACKGROUND: Supplemental oxygen is used during every general anesthesia. However, for the maintenance phase of a general anesthesia, in most cases the longest part of anesthesia, only scarce evidence of dosing supplemental oxygen exists. Oxygen is a well-known coronary vasoconstrictor and thus may contribute to cardiovascular complications especially in vulnerable high-risk patients with coronary artery disease undergoing major non-cardiac surgery. Myocardial biomarkers are early indicators of myocardial injury. Oxygen supply demand mismatches due to coronary artery disease aggravated by hyperoxia might be displayed by changes from the biomarker's baseline-values. This study is designed to detect changes in myocardial biomarkers levels associated with perioperative hyperoxia. METHODS: This prospective randomized controlled interventional trial investigates the impact of maintaining perioperative high oxygen supplementation in high-risk patients undergoing non-cardiac vascular surgery on cardiac biomarkers, myocardial strain and outcome in 110 patients. Patients are allocated to be supplemented with either 0.3 (normal) or 0.8 (high) fraction of inspired oxygen (FiO2) perioperatively. Included is a short crossover phase during which transesophageal echocardiography is used to evaluate myocardial function at FiO2 0.3 and 0.8 by strain analysis in each patient. Patients will be followed up for complications at 30 days and 1 year. CONCLUSION: The trial is designed to evaluate perioperative changes from baseline myocardial biomarkers associated with perioperative FiO2. Furthermore, exploration and correlation of changes in biomarkers, acute early changes in myocardial function and clinical outcomes induced by different FiO2 may be possible.

Prognostic value of left ventricular systolic function before vascular surgery: a systematic review.

BACKGROUND: Vascular surgery carries a high risk of post-operative cardiac complications. Recent studies have shown an association between asymptomatic left ventricular systolic dysfunction and increased risk of major adverse cardiovascular events (MACE). This systematic review aims to evaluate the prognostic value of left ventricular function as determined by left ventricular ejection fraction (LVEF) measured by resting echocardiography before vascular surgery. METHODS: This review conformed to PRISMA and MOOSE guidelines. PubMed, OVID Medline and Cochrane databases were searched from inception to 27 October 2022. Eligible studies assessed vascular surgery patients, with multivariable-adjusted or propensity-matched observational studies measuring LVEF via resting echocardiography and providing risk estimates for outcomes. The primary outcomes measures were all-cause mortality and congestive heart failure at 30 days. Secondary outcome included the composite outcome MACE. RESULTS: Ten observational studies were included (4872 vascular surgery patients). Studies varied widely in degree of left ventricular systolic dysfunction, symptom status, and outcome reporting, precluding reliable meta-analysis. Available data demonstrated a trend towards increased incidence of all-cause mortality, congestive heart failure and MACE in patients with pre-operative LVEF <50%. Methodological quality of the included studies was found to be of moderate quality according to the Newcastle Ottawa Checklist. CONCLUSION: The evidence surrounding the prognostic value of LVEF measurement before vascular surgery is currently weak and inconclusive. Larger scale, prospective studies are required to further refine cardiac risk prediction before vascular surgery.

Editor's Choice - Short Term Cost Effectiveness of Radiofrequency Ablation and High Ligation and Stripping for Great Saphenous Vein Incompetence.

OBJECTIVE: Superficial venous incompetence (SVI) is a common disease that causes significant quality of life (QoL) impairment. There is a need for more health economic evaluations of SVI treatment. The aim of this study was to perform a cost effectiveness analysis in patients with great saphenous vein (GSV) incompetence comparing radiofrequency ablation (RFA), high ligation and stripping (HL/S), and no treatment or conservative treatment with one year follow up. METHODS: Randomised controlled trial economic analysis from an ongoing trial; 143 patients (156 limbs) with GSV incompetence (CEAP clinical class 2 - 6) were included. Treatment was performed with RFA or HL/S. Follow up was performed up to one year using duplex ultrasound, revised venous clinical severity score (r-VCSS), Aberdeen Varicose Vein Questionnaire (AVVQ), and EuroQol-5D-3L (EQ-5D-3L). RESULTS: Seventy-eight limbs were treated with RFA and HL/S respectively. No treatment or conservative treatment was assumed to have zero in treatment cost and no treatment benefit. In the RFA group, one limb had reflux in the GSV after one month and three limbs after one year. In HL/S, two limbs had remaining reflux in the treated area at one month and one year. Both disease severity (r-VCSS, p = .004) and QoL (AVVQ, p = .021 and EQ-5D-3L, p = .028) were significantly improved over time. The QALY gain was 0.21 for RFA and 0.17 for HL/S. The cost per patient was calculated as €1 292 for RFA and €2 303 for HL/S. The cost per QALY (compared with no treatment or conservative treatment) was €6 155 for RFA and €13 549 for HL/S. With added cost for days absent from work the cost per QALY was €7 358 for RFA and €24 197 for HL/S. The cost per QALY for both methods was well below the threshold suggested by Swedish National Board of Health. CONCLUSION: RFA is more cost effective than HL/S and no treatment or conservative treatment at one year follow up.

Internal jugular vein pressure monitoring guided venous reconstruction could improve perioperative safety after superior vena cava resection for mediastinal tumors: a cohort study.

INTRODUCTION: After superior vena cava (SVC) resection, the decision on unilateral or bilateral reconstruction was mostly based on the expertise of surgeons without objective measurements. This study explored the use of internal jugular vein pressure (IJVP) monitoring to guide the SVC reconstruction strategy. METHODS: In a retrospective cohort, perioperative outcomes of unilateral and bilateral reconstruction based on surgeons' experience were compared. Then, IJVP threshold was measured when temporarily clamping the left innominate vein in a testing cohort. Venous reconstruction according to IJVP monitoring was performed in a prospective validation cohort afterward. Perioperative outcomes were compared between the prospective and the retrospective cohorts. For some interested variables, intuitive explanations would be given using Bayesian methods. Potential risk factors for postoperative complications were investigated by multivariable analysis. RESULTS: From March 2009 to September 2022, 57 patients underwent SVC reconstruction based on surgeons' experience. Bayesian analysis indicated a posterior probability of 80.49% that unilateral reconstruction had less blood loss than bilateral reconstruction (median 550 ml vs. 1200 ml). Cerebral edema occurred in two patients after unilateral reconstruction. In the testing cohort, median IJVP was 22.7 (18-27) cmH 2 O after temporary left innominate vein clamping in 10 patients. In the prospective cohort, unilateral reconstruction only was performed if the contralateral IJVP was <30 cmH 2 O in 16 patients. Bilateral reconstruction was performed if IJVP was ≥30 cmH 2 O after unilateral bypass in nine patients. No cerebral edema occurred in the prospective cohort. Less postoperative complications occurred in the prospective cohort than the retrospective cohort (12.0 vs. 38.6%, P =0.016). Upon multivariable analysis, IJVP-monitoring guided SVC reconstruction was associated with significantly less postoperative complications ( P =0.033). CONCLUSIONS: Intraoperative IJVP-monitoring is a useful strategy for selection of unilateral or bilateral SVC reconstruction and improving perioperative safety in patients with mediastinal tumors.

CHIVA for dummies.

BACKGROUND: Sparing the Great Saphenous Vein capital for possible arterial substitution and recurrence decrease may be an alternative to current ablation options for Varicose Veins treatment. Conservative surgery of varicose veins (CHIVA) was suggested in 1988 by Franceschi, by limited veins interruptions in strategic points. However, the method did not diffuse due to the need for high Duplex expertise to determine the procedure in every single patient. METHOD: Evaluation of the literature regarding saphenous sparing, with special reference to CHIVA. RESULT: It has been realized that basic Ultrasound expertise is sufficient for performing GSV conservation. Most of the time, only a few parameters are needed: a junction competence assessment and a re-entry perforator position. CONCLUSION: For achieving the goal of saphenous conservative treatment, a limited phlebectomy and possible Junction interruption (crossotomy) may be a simplified solution.