Painless ulceration due to digital hypoperfusion ischaemic syndrome: case report and literature review.

Digital hypoperfusion ischaemic syndrome (DHIS), also known as steal syndrome, is a well recognised serious complication of haemodialysis (HD) access creation. The clinical presentation varies from cyanosis to tissue loss due to necrosis or gangrene. In this article, we present a case of painless digital ulceration due to DHIS and provide a review of the literature. A 40-year-old-female presented with multiple painless digital ulcerations of the left hand. Her medical profile included atherosclerotic disease, hypertension, hyperparathyroidism and type I diabetes causing retinopathy, peripheral neuropathy, gastroparesis and end-stage renal disease (ESRD). Her ESRD required HD with the construction of a left-arm basilic vein transposition arteriovenous fistula (AVF). A year later, she developed intermittent, painless ulcerations of the left hand. A Doppler ultrasound confirmed the diagnosis of DHIS. The patient was treated with AVF ligation surgery. At six months postoperatively, she had near complete re-epithelialisation of her ulcers. This case is unique in that the patient did not have preceding pain, likely due to her underlying diabetic neuropathy. While DHIS in haemodialysis patients with AVF is well documented in literature, digital ulceration in this context is an advanced form of this condition. Early recognition of digital ulceration as a complication of DHIS may enable early intervention and prevent permanent damage.

The Unique Case of Acute Limb Ischemia in a Patient With a Patent Foramen Ovale.

Acute limb ischemia (ALI) is the sudden onset of decreased blood supply to the extremities and carries a poor prognosis for the affected limb and survival. A rare but well-recognized embolic etiology is a paradoxical embolism, the translocation of a thrombus from venous to arterial circulation through an intracardiac communication, most commonly a patent foramen ovale. The presentation of ALI secondary to a PFO-mediated paradoxical embolism is most often accompanied by combinations of deep vein thrombosis (DVT), pulmonary embolism (PE), and an acute cerebral or visceral ischemia. We present the first documented case of a Rutherford class I ALI secondary to a PFO-mediated paradoxical embolism, ipsilateral DVT, and PE in a 29-year-old female who was surgically managed for her disabling claudication rather than limb salvage. The overlapping presentation of a viable ALI and ipsilateral DVT created a challenging clinical diagnosis. Our review of the literature on PFO-mediated paradoxical emboli involved 43 reports including 51 patients with various arterial thromboses; 19 of these cases involved lower extremity ALI. This case report is the first case to date that demonstrates a paradoxical embolism causing acute lower extremity ischemia with ipsilateral DVT and no additional limb/visceral ischemia to suggest the diagnosis of ALI. We also highlight the role that quality of life plays in vascular surgical decision-making, extending ALI management goals to not only reducing mortality and major amputations, but also improving quality of life.

Canadian Cardiovascular Society 2022 Guidelines for Peripheral Arterial Disease.

Patients with widespread atherosclerosis such as peripheral artery disease (PAD) have a high risk of cardiovascular and limb symptoms and complications, which affects their quality of life and longevity. Over the past 2 decades there have been substantial advances in diagnostics, pharmacotherapy, and interventions including endovascular and open surgical to aid in the management of PAD patients. To summarize the evidence regarding approaches to diagnosis, risk stratification, medical and intervention treatments for patients with PAD, guided by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework, evidence was synthesized, and assessed for quality, and recommendations provided-categorized as weak or strong for each prespecified research question. Fifty-six recommendations were made, with 27% (15/56) graded as strong recommendations with high-quality evidence, 14% (8/56) were designated as strong recommendations with moderate-quality evidence, and 20% (11/56) were strong recommendations with low quality of evidence. Conversely 39% (22/56) were classified as weak recommendations. For PAD patients, strong recommendations on the basis of high-quality evidence, include smoking cessation interventions, structured exercise programs for claudication, lipid-modifying therapy, antithrombotic therapy with a single antiplatelet agent or dual pathway inhibition with low-dose rivaroxaban and aspirin; treatment of hypertension with an angiotensin converting enzyme or angiotensin receptor blocker; and for those with diabetes, a sodium-glucose cotransporter 2 inhibitor should be considered. Furthermore, autogenous grafts are more effective than prosthetic grafts for surgical bypasses for claudication or chronic limb-threatening ischemia involving the popliteal or distal arteries. Other recommendations indicated that new endovascular techniques and hybrid procedures be considered in patients with favourable anatomy and patient factors, and finally, the evidence for perioperative risk stratification for PAD patients who undergo surgery remains weak.

Reduction in Diabetes-Related Major Amputation Rates After Implementation of a Multidisciplinary Model: An Evaluation in Alberta, Canada.

BACKGROUND: Diabetes-related lower limb amputations (LLAs) are a major complication that can be reduced by employing multidisciplinary center frameworks such as the Toe and Flow model (TFM). In this study, we investigate the LLAs reduction efficacy of the TFM compared to the standard of care (SOC) in the Canadian health-care system. METHODS: We retrospectively reviewed the anonymized diabetes-related LLA reports (2007-2017) in Calgary and Edmonton metropolitan health zones in Alberta, Canada. Both zones have the same provincial health-care coverage and similar demographics; however, Calgary operates based on the TFM while Edmonton with the provincial SOC. LLAs were divided into minor and major amputation cohorts and evaluated using the chi-square test, linear regression. A lower major LLAs rate was denoted as a sign for higher efficacy of the system. RESULTS: Although LLAs numbers remained relatively comparable (Calgary: 2238 and Edmonton: 2410), the Calgary zone had both significantly lower major (45%) and higher minor (42%) amputation incidence rates compared to the Edmonton zone. The increasing trend in minor LLAs and decreasing major LLAs in the Calgary zone were negatively and significantly correlated (r = -0.730, p = 0.011), with no significant correlation in the Edmonton zone. CONCLUSIONS: Calgary's decreasing diabetes-related major LLAs and negative correlation in the minor-major LLAs rates compared to its sister zone Edmonton, provides support for the positive impact of the TFM. This investigation includes support for a modernization of the diabetes-related limb preservation practice in Canada by implementing TFMs across the country to combat major LLAs.

A cohort study of nutrition practices in the intensive care unit following abdominal aortic aneurysm repair.

INTRODUCTION: Enteral nutrition within 48 hours of intensive care unit (ICU) admission is recommended for the ICU population. Major vascular surgery patients have a higher incidence of pre- and postoperative malnutrition compared with the general surgical population. Our objectives were to determine if early feeding (within 48 hours of admission) is achievable and well tolerated, identify factors that predict early feeding, and determine if there is an association between early feeding and in-hospital mortality among abdominal aortic aneurysm (AAA) repair patients. METHODS: A retrospective cohort study was conducted among 145 postsurgical AAA repair patients admitted to the ICU within 48 hours of surgery. Kaplan-Meier methods and Cox proportional hazard multiple regression were used to analyze the data. RESULTS: Only 35 (24%) patients received early feeding. Patients were more likely to be fed early if they were male (adjusted hazard ratio [aHR] = 2.3; 95% confidence interval [CI], 0.8-6.7; P = .13), had endovascular AAA repair (aHR = 2.9; 95% CI, 1.4-6.2; P = .006), had less blood loss (<4 L) during surgery (aHR = 2.3; 95% CI, 0.7-7.2; P = .14), and had shorter length of ventilation (<48 hours) (aHR = 2.2; 95% CI, 1.1-4.8; P = .048). Of 44 patients fed via enteral nutrition (EN), 27 (61%) achieved nutrition adequacy (>80% EN goal) during ICU admission. After controlling for other factors, 14-day mortality was not related to feeding time (aHR = 1.1; P = .88). CONCLUSION: Early feeding was achieved in a minority of patients following AAA repair, was related to type of surgery and duration of mechanical ventilation, and was tolerated as well as later introduced feedings. Randomized trials are needed to determine safety and benefits of early feeding in this patient group.

Characterization of the upper limb arterial properties during reactive hyperemia.

The radial artery (RA) pressure waveform is commonly used to reconstruct the central aortic pressure waveform. Because the RA pressure waveform has been used as input to this process, its features that are dependent on the local arterial properties can influence the final reconstructed aortic waveform. In this study, we determined the effects of altered upper limb pulse wave velocity (PWV) and local wave reflection parameters on RA pressure waveform augmentation (RA-AIx). Twenty healthy volunteers (10 men) between the ages of 18 and 35 years of age were recruited. Simultaneous pressure waveforms were acquired using arterial tonometers from the right carotid and the radial arteries, prior to and following tourniquet induced hyperemia. The phase velocities from the pressure wave transfer function were used to estimate the pulse wave velocity (PWV(infinity)), the local reflection coefficient (Gamma) and an estimate of the terminal impedance of the upper limbs, PWV(0+). The RA-AIx was represented as a linear, three-parameter model that included the input (the AIx of the carotid artery pressure waveform, CA-AIx), the Gamma and PWV(infinity) of the arm. Tourniquet induced hyperemia did not alter Gamma but reduced PWV(infinity), and PWV(0+) and increased RA-AIx. Multiple linear regression analysis indicated that RA-AIx was increased by high levels of CA-AIx and PWV(infinity) and decreased by elevated Gamma. The relative weighing of CA-AIx, Gamma and PWV(infinity) on RA-AIx were 3:2:1, respectively. The AIx of RA is determined to an equal extent by the input and local factors. Interpretation of the AIx of the RA and the reconstructed central aortic waveform should be made in the context of this relationship.

Implant degradation and poor healing after endovascular repair of abdominal aortic aneurysms: an analysis of explanted stent-grafts.

PURPOSE: To study explanted stent-grafts to achieve a better understanding of the mechanisms of failure after endovascular treatment of abdominal aortic aneurysms (AAA). METHODS: Twelve stent-grafts were harvested at autopsy (n=3) or during surgical conversion (n=9). Device alterations were investigated by macroscopic examination, radiography, and surface analysis techniques. Healing around the implants was studied via histology and immunohistochemistry, with particular attention to the stent-graft/tissue interface. RESULTS: Degradation was more important with Vanguard stent-grafts (off the market) than with AneuRx and Talent stent-grafts, but rupture of nitinol wires and poor surface finish in Talent stent-grafts raise concern about their corrosion resistance and long-term stability. Poor healing was observed around stent-grafts even after several years of implantation, with absence of vascular smooth muscle cells, fibroblasts, and collagen formation. In addition to the well-known foreign body reaction around the graft, numerous polymorphonuclear cells characteristic of the first step of healing were present in tissues around stent-grafts retrieved at surgical conversion. Factors explaining the lack of tissue organization around stent-grafts are discussed. CONCLUSION: The long-term stability of implants remains a concern and requires more transparency from manufacturers regarding the surface properties of their devices. Lack of neointima formation impairs biological fixation of the implant to the vessel wall, leading to possible endoleaks and migration. New-generation stent-grafts promoting biological fixation should be developed to improve clinical outcomes of this minimally invasive treatment.

Endovascular treatment for aortic disease: is a surgical environment necessary?

OBJECTIVE: Interventional radiologists, cardiologists, and vascular surgeons are capable of performing endovascular procedures successfully in their respective environments. Suboptimal anatomy or intraoperative technical problems can be encountered, and endovascular management alone is not always suitable. The objectives of this study were to define the incidence of adjunctive surgical techniques, to discuss the rationale for endovascular reconstruction in a well-developed surgical environment, and to assess the effect of experience on the incidence of adjunctive repair. METHODS: All primary aortic and aortoiliac elective, urgent, and emergent endovascular procedures performed at the Peter Lougheed Center and entered into a prospective database from May 25, 1999 to June 01, 2005, were reviewed. All adjunctive surgical techniques to enable stent deployment, enhance attachment site, or solve intraoperative difficulties were captured. The study period was divided into two time periods based on learning curve data to assess the effect of experience on the rate of adjunctive repairs. RESULTS: Four hundred thirty-eight patients underwent elective (80%), urgent (15%), or emergent (5%) endovascular procedures during the study period. These consisted of 101 thoracic and 337 abdominal operations, including the use of 13 fenestrated stents. One hundred thirty-nine patients (31.7%) required 180 open surgical procedures. Complete data were available for the entire patient cohort. The mean follow-up was 793.2 days (SD, 519.1 days). Procedures were necessary for vascular access, arterial dissection/rupture, limb ischemia, and enhancement/elongation of the stent attachment site. The persistent endoleak rate was 5.3%, the late rupture rate was 0.7%, the conversion rate was 1.6%, the 30-day surgical mortality rate was 3.2%, all-cause mortality to date is 7.3%, and the reintervention rate was 4.6%. There was no statistically significant effect of the learning curve on the incidence of surgical adjunctive procedures in either the thoracic group (11/26 [42.3%] for phase 1 vs 17/75 [22.6%] for phase 2) or the abdominal group (14/50 [28.0%] for phase 1 vs 97/287 [33.8%] for phase 2). Overall, 31.5% of patients required adjunctive surgical repair. CONCLUSIONS: Successful endografting requires endovascular expertise in addition to a well-developed surgical environment to increase applicability and decrease patient risk. Despite advances in endovascular technology, hybrid techniques will continue to be required to achieve good overall success rates.