Society for Vascular Surgery appropriate use criteria for management of intermittent claudication.

The Society for Vascular Surgery appropriate use criteria (AUC) for the management of intermittent claudication were created using the RAND appropriateness method, a validated and standardized method that combines the best available evidence from medical literature with expert opinion, using a modified Delphi process. These criteria serve as a framework on which individualized patient and clinician shared decision-making can grow. These criteria are not absolute. AUC should not be interpreted as a requirement to administer treatments rated as appropriate (benefit outweighs risk). Nor should AUC be interpreted as a prohibition of treatments rated as inappropriate (risk outweighs benefit). Clinical situations will occur in which moderating factors, not included in these AUC, will shift the appropriateness level of a treatment for an individual patient. Proper implementation of AUC requires a description of those moderating patient factors. For scenarios with an indeterminate rating, clinician judgement combined with the best available evidence should determine the treatment strategy. These scenarios require mechanisms to track the treatment decisions and outcomes. AUC should be revisited periodically to ensure that they remain relevant. The panelists rated 2280 unique scenarios for the treatment of intermittent claudication (IC) in the aortoiliac, common femoral, and femoropopliteal segments in the round 2 rating. Of these, only nine (0.4%) showed a disagreement using the interpercentile range adjusted for symmetry formula, indicating an exceptionally high degree of consensus among the panelists. Post hoc, the term "inappropriate" was replaced with the phrase "risk outweighs benefit." The term "appropriate" was also replaced with "benefit outweighs risk." The key principles for the management of IC reflected within these AUC are as follows. First, exercise therapy is the preferred initial management strategy for all patients with IC. Second, for patients who have not completed exercise therapy, invasive therapy might provide net a benefit for selected patients with IC who are nonsmokers, are taking optimal medical therapy, are considered to have a low physiologic and technical risk, and who are experiencing severe lifestyle limitations and/or a short walking distance. Third, considering the long-term durability of the currently available technology, invasive interventions for femoropopliteal disease should be reserved for patients with severe lifestyle limitations and a short walking distance. Fourth, in the common femoral segment, open common femoral endarterectomy will provide greater net benefit than endovascular intervention for the treatment of IC. Finally, in the infrapopliteal segment, invasive intervention for the treatment of IC is of unclear benefit and could be harmful.

Improved patency after axillofemoral bypass for aortoiliac occlusive disease.

OBJECTIVE: Axillofemoral bypasses (AxFBs) have been used since 1962 to treat aortoiliac disease. In the past, reported patency rates (37%-76%) for these extra-anatomic grafts have been inferior to those for anatomic aortic grafting. Reported low survival rates after AxFB (40%-50%) have confirmed that these procedures have been used primarily in patients at high risk for complications from aortofemoral bypass. However, modern medical and anesthesia management, preoperative scanning, donor artery preparation, postoperative graft surveillance, and graft technology may improve outcomes after AxFB, possibly supporting expansion of its use. We therefore report our last 15-year experience with AxFB. METHODS: Ring-reinforced, 8-mm expanded polytetrafluoroethylene grafts were used in all cases. The cross-femoral limb of axillobifemoral bypass (AxBFB) grafts was preconstructed. Heparin was administered intraoperatively, with protamine reversal. Loss of primary patency was defined as graft thrombosis of part or all of the inserted graft. Five-year primary patency rates were calculated by Kaplan-Meier analysis. RESULTS: Between February 1991 and June 2016, a total of 161 grafts were inserted (85 AxBFBs and 76 axillounifemoral bypasses [AxUFBs]) in 91 male and 70 female patients (median age, 72.6 years; mean age, 73 years; range, 41-94 years). Indications for treatment were rest pain (49.6%), ischemic lesions (26%), claudication (22.3%), failed prior revascularization (9.3%), infection (3.7%), and dissecting aneurysm (1.2%). Reasons for performing AxFB rather than aortofemoral bypass were hostile aorta (44.1%), high risk (19.2%), prior failed reconstruction (12.4%), advanced age (8.7%), infection (4.3%), hostile abdomen (4.3%), aortic dissection (0.6%), and morbid obesity (0.6%). During follow up, 63 patients died, 17 within the first year; but only 3 patients died within 30 days of surgery (performed to treat an acute aortic occlusion). The 5-year survival rate was 55%. Five-year patency rates were 83.7% for all procedures, 81.8% for AxBFB, and 85.5% for AxUFB; the difference between AxBFB and AxUFB was not significant. CONCLUSIONS: Our data indicate that AxBFB and AxUFB performed with the use of modern protocols and technology may render them an acceptable valid primary intervention in patients in whom endovascular treatment has failed or is unlikely to offer long-term success. The simplicity of performing these grafts and their low mortality and morbidity lend their application to surgeons with limited open aortic experience. Because AxUFB and AxBFB have similar patency rates, AxBFB should be reserved for bilateral indications.

Heparin-bonded expanded polytetrafluoroethylene femoropopliteal bypass grafts outperform expanded polytetrafluoroethylene grafts without heparin in a long-term comparison.

OBJECTIVE: Expanded polytetrafluoroethylene (ePTFE) grafts have become an acceptable prosthetic alternative to autologous vein for infrainguinal arterial reconstructions. Recently, heparin bonding to the graft's luminal surface has been used as an adjunctive method of improving graft patency. We retrospectively evaluated a prospective experience with heparin-bonded ePTFE (HePTFE) vs the results of a prior experience with standard ePTFE (SePTFE) to compare patency rates in above-knee (AK) and below-knee (BK) femoropopliteal bypass through the 5-year follow-up. METHODS: Prosthetic femoropopliteal bypasses performed by our four-surgeon group were constructed using 6-mm SePTFE grafts before August 2007. Subsequently, all such bypasses were constructed using 6-mm HePTFE (Propaten graft; W. L. Gore & Associates, Flagstaff, Ariz). The surgical technique used in all cases throughout the study was similar irrespective of surgeon or graft material. Loss of primary patency was defined by graft thrombosis; duplex scan confirmed graft failure. Descriptive estimation of patency rates was carried out using standard Kaplan-Meier methods. Cox proportional hazards regression was used to analyze relationships between predictors and time to loss of patency. RESULTS: There were 192 AK (87 Propaten, 105 SePTFE) and 60 BK (42 Propaten, 18 SePTFE) grafts. Overall primary patency for Propaten was statistically better than SePTFE at years 1 (93.6% vs 84.2%), 2 (79.7% vs 73.8%), 3 (79.7% vs 69.5%), 4 (74.5% vs 59.9%) and 5 (74.5% vs 56.2%; log-rank test, P = .036). Five-year primary patency was superior for Propaten AK grafts (85.2% vs 59.3%; log-rank test, P = .028) and for Propaten BK grafts (59.6% vs 0.0/undeterminable; log-rank test, P = .016). Variables significantly associated with loss of patency for Propaten and SePTFE were claudication (hazard ratio [HR], 0.41), age (HR, 0.95), isolated popliteal artery (HR, 3.1-4.4), and ankle-brachial index after the procedure (HR, 0.10). Controlling for conduit effect, clopidogrel use did not significantly affect patency (P = .076). No grafts were associated with heparin-induced thrombocytopenia. CONCLUSIONS: These data show that the Propaten HePTFE graft offered significantly better long-term patency over the SePTFE graft, suggesting Propaten as the prosthetic graft of choice for bypasses to the femoropopliteal artery when autologous vein is unavailable or inappropriate.

Essentials of negotiating for employment in a changing environment.

Evolving changes in health care in the United States are causing new graduates and self-employed physicians to consider employment with large groups and health systems. Familiarity with the principles, proper conduct, and mechanics of negotiating an employment agreement will be important for vascular surgeons making such a decision. The various components of compensation packages and contract language need to be critically evaluated. To facilitate an understanding of the complexities involved in employment contracts, strategies to avoid making negotiating mistakes are discussed.

Contralateral carotid artery occlusion is not a contraindication to carotid endarterectomy even if shunts are not routinely used.

OBJECTIVE: Although controversial, carotid artery stenting (CAS) has been proposed as being safer than carotid endarterectomy (CEA) for patients with a contralateral internal carotid occlusion (CCO). Arguably, with a CCO, CAS should be even safer than CEA if a shunt is not used. Accordingly, we reviewed our experience with 2183 CEAs performed routinely without a shunt to evaluate the risk of CEA performed in a subset of 147 patients with a CCO. METHODS: Between 1988 and 2011, 147 CEAs (111 men [75%], 36 women [25%]) were routinely performed without a shunt despite CCO. Of these patients, 76% were asymptomatic. CEAs were performed by seven surgeons using standard techniques (not eversion), with patients under general anesthesia and blood pressure maintained at >130 mm Hg. All patients received heparin (7500 U), and protamine reversal was routine. Median cross-clamp time was 20 minutes (range, 14-40 minutes). RESULTS: Three neurologic events occurred ≤ 30 days (2.0%). One transient ischemic attack (TIA) occurred immediately, and one occurred on the first postoperative day due to occlusion of the endarterectomy site. One patient sustained an immediate stroke and died of a large computed tomography-documented atheroembolic shower. CONCLUSIONS: Our data demonstrate the safety of CEA in the presence of a CCO, even when performed without a shunt. It is unlikely that the stroke or delayed TIA could be attributed to nonshunting or CCO. Even if so, the stroke and death rates would be lower than those previously reported for patients undergoing CEA in the presence of a CCO. This may be due to short cross-clamp times, careful technique, general anesthesia, and blood pressure support. Given these low adverse event rates, our experience refutes the assumption that patients with a CCO are at such a high risk for CEA that the only alternative is CAS.

Influence and critique of the JUPITER Trial (Statins v no statins for primary prevention of cardiovascular events in patients with normal lipids and elevated C-reactive protein).

Perhaps no recent trial in primary prevention of cardiovascular disease has resulted in more controversy than the JUPITER (Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvastatin) trial, which was first published in 2008. The study evaluated a patient cohort previously considered to be "healthy," ie, men 50 years of age or older and women 60 years of age or older, who did not have a history of cardiovascular disease and, at the initial screening visit, had a low-density lipoprotein cholesterol level of <130 mg/dL (3.4 mmol/L) and a high-sensitivity C-reactive protein level ≥2.0 mg/L. The trial showed that rosuvastatin is a powerful statin that, at lower doses, can reduce low-density lipoprotein cholesterol to levels previously not seen with other agents. Concurrently, it can also reduce high-sensitivity C-reactive protein to levels below what are considered normal, but that might be more physiologic. In the trial participants who achieved such lowering, major cardiovascular events, including venous thromboembolic events, were reduced even in the short term. Despite these results, many still question whether the trial results should influence high-sensitivity C-reactive protein testing or the prescription of statins for individuals at low risk for cardiovascular disease.

Long-term safety of left renal vein division and ligation to expedite complex abdominal aortic surgery.

BACKGROUND: Left renal vein division and ligation (LRVDAL) is performed to facilitate complex abdominal aortic surgery. Surgeons restore continuity of the vein due to concern that ligation could cause renal compromise or hematuria. However, we report the short and long-term safety of left renal vein division and ligation. METHOD: Between 1992 and 2007, we divided the left renal vein in 56 patients (40 males, 16 females) ages 57 to 84 (average 74-years-old) who were treated for aortic occlusive disease (9) or abdominal aortic aneurysm (47). Patients requiring concomitant renal artery reconstruction were excluded from this review. Suprarenal cross-clamp was used in 51 patients with temporary vessel-loop control of the renal arteries. Creatinine (Cr) and glomerular filtration rates (eGFR) were measured pre-, post-, and long-term after surgery. Outpatient records of all patients that had survived more than 12 months were also reviewed in order to evaluate the late effects on renal function or symptoms possibly related to LRVDAL. RESULTS: Median procedure duration was 157 (61-375) minutes. Median cross-clamp time was 16 (10-45) minutes. Median intensive care unit (ICU) and hospital length of stays were 2 (1-11) days and 7 (4-58) days, respectively. There were no deaths. There were no complications directly related to renal vein ligation. Hematuria, seen in 2 patients, was a result of traumatic insertion of a Foley catheter. Median pre-op and discharge Cr levels were 1.1 mg/dL (0.7-2.4 mg/dL) and 1.1 mg/dL (0.6-2.1 mg/dL), respectively (P < .5). Median change in Cr was 0.0 mg/dL and only increased in 14 patients (maximum increase 0.9 mg/dL). Median pre-op and discharge eGFR was 61 mL/minute (28-137 mL/minute/1.73 m2) and 67 mL/minute (32-138 mL/minute/1.73 m2), respectively (P < .5). Cr and eGFR in the 2 patients with a Cr of >2.0 mg/dL remained unchanged post-op. Only 2 patients with a Cr of <2.0 mg/dL had a post-op Cr >2.0 mg/dL and both returned to normal by day 3 post-op. Thirty-six patients have been followed for more than a year (median 34.5 months, maximum 144 months) and Cr has remained stable in all but 2 patients. These 2 patients, both with a pre-op Cr of 1.5 mg/dL, subsequently developed Cr levels of 2.1 mg/dL and 2.4 mg/dL but maintained baseline Cr levels for 25 and 34 months, respectively, before demonstrating these elevated levels which have proven to be unrelated to renal vein ligation. Hematuria and flank pain have never been recorded after discharge. CONCLUSION: Restoration of left renal vein continuity after LRVDAL may be unnecessary since renal compromise and hematuria was not encountered in this long-term analysis.

Which diabetics are at risk for lower-extremity problems and what preventive measures can be taken?

Diabetes mellitus is a well-known risk factor for development and progression of peripheral arterial disease. Prospective cardiovascular clinical trials have also clearly demonstrated that diabetics fare worse than their nondiabetic counterparts. Diabetics also differ from nondiabetics in that multiple revascularization procedures may be required in order for the clinical outcome to be equivalent to that of a nondiabetic patient. However, by advocating an aggressive approach to peripheral arterial disease, good results in survival and limb salvage can be achieved in diabetic patients despite the presence of increased medical comorbidities. Key to the management of such patients will be identifying which diabetic patients will be at most risk so that preventive measures can be undertaken.

CryoPlasty therapy of the superficial femoral and popliteal arteries: a reappraisal after 44 months' experience.

OBJECTIVES: Long-term patency remains a significant hurdle in the minimally invasive treatment of arteriosclerosis in the superficial femoral (SFA) and popliteal arteries. CryoPlasty therapy (PolarCath, Boston Scientific Corp, Natick, Mass) is a novel approach designed to significantly reduce injury, elastic recoil, neointimal hyperplasia, and constrictive remodeling. The technique combines the dilatation forces of percutaneous transluminal angioplasty (PTA) with cold thermal energy applied to the plaque and vessel wall. We previously reported a technical success rate of 96% and a 12-month freedom from restenosis rate of 82.2%. However, a review of the original cohort supplemented by experience with a further 47 lesions has demonstrated less desirable results. METHODS: From December 2003 through July 2007, 92 lesions in 64 consecutive patients were treated and followed up for a median of 16 months with statistically significant follow-up at 24 months. RESULTS: The immediate technical success rate was 88%. Nine stents were immediately required after unsuccessful CryoPlasty (9.8%) five of which were as a result of a dissection. No unanticipated adverse events occurred, specifically, no thrombus, acute occlusions, distal embolizations, aneurysms, or groin complications. Vascular calcification was responsible for technical failure in six of the 11 immediately unsuccessful procedures. Freedom from restenosis for successfully treated lesions was 57% and 49% at 12 and 24 months, respectively. CryoPlasty of heavily calcified lesions, vein graft lesions, and in-stent stenosis faired poorly. Excluding these lesions from analysis would have resulted in an immediate success of 94% (81 of 86) and freedom from restenosis of 61% and 52% at 12 and 24 months, respectively. However, on an intention-to-treat basis, freedom from restenosis was 47% and 38% at 12 and 24 months, and CryoPlasty added approximately $1700 to the cost of each procedure. CONCLUSION: Analysis of this expanded, longer-term data suggests that our earlier, smaller study provided an overly optimistic appraisal of the benefits of CryoPlasty. It is possible that a larger analysis might have identified a subset of patients or lesions that would benefit from CryoPlasty, but considering the additional cost, we no longer use this technique in our practice.

Heat shock protein 70 is induced in mouse human colon tumor xenografts after sublethal radiofrequency ablation.

BACKGROUND: Radiofrequency ablation (RFA) destroys tumor cells by generating high temperatures through ionic vibration. Tumor recurrence may be a direct function of sublethal temperature. Further, a set of proteins called heat shock proteins (HSPs) can be synthesized under heat stress to facilitate recovery of tumor cells from heat damage. METHODS: Subcutaneous xenografts were induced in nude mice by injection with HT29 human colon cancer cells. The tumors were exposed surgically and subjected to RFA. The tumors were randomly assigned to achieve a target tumor temperature of 42 degrees C, 45 degrees C, or 50 degrees C. Total RNA and cell lysates were isolated from tumor tissues and subjected to reverse transcription-polymerase chain reaction and Western blot analyses, respectively, at various time points after treatments for assessing HSP expression. For in vitro experiments, HT29 cells were subjected to variable temperatures, and HSP expression was assayed. RESULTS: During a 50-day follow-up, the recurrence rates were 0% at 50 degrees C, 30% at 45 degrees C, and 100% at 42 degrees C. The messenger RNA and protein levels of HSP90 and HSP27 remained unchanged after RFA at 45 degrees C; however, HSP70 was induced at 4 and 10 hours after RFA. In vitro HT29 culture cells subjected to a heated water bath exhibited a cellular sensitivity to heat and change of HSP expression similar to those in tumor xenografts subjected to RFA. CONCLUSIONS: Our data establish the requisite heat parameters during RFA for human colon tumors in vitro and in vivo. Because HSP70 plays an important role in protecting cell death from a variety of stresses, HSP70 could be a potential target for enhancing the efficacy of RFA.

Apoptosis induced by cryo-injury in human colorectal cancer cells is associated with mitochondrial dysfunction.

Cryotherapy, a method of in situ ablation, is used in the treatment of colorectal liver metastases with variable results. During the treatment, the central area of treated tumor undergoes necrotic destruction by lethal cryo-injury; however, the cellular response of tumor exposed to sublethal cryo-injury at the peripheral zone is unclear. In our study, we have identified the induction of apoptosis by cryo-injury at -10 degrees C in 4 colorectal cancer cell lines (HT29, HCT116, KM12C and KM12SM). The apoptosis was characterized by chromatin condensation, transferase-mediated dUTP nick end-labeling (TUNEL) staining, proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) and cytokeratin 18, and activation of caspase-3. The occurrence and intensity of cryo-induced apoptosis did not correlate with the functional status of p53 in the cell lines studied. The expression of anti-apoptotic proteins (Bcl-2, Bcl-X(L)) and pro-apoptotic proteins (Bax, Bcl-X(S), Bad, and Bak) in response to cryo-injury varied in this cell line panel. The basal level of Bcl-2/Bax protein ratio correlated inversely to the apoptotic rate. We further demonstrated that Bax level decreased in cytosol and increased in mitochondria, followed by a loss of mitochondrial membrane potential after cryo-injury in HT29 cells. These findings indicate that cryo-injury induces apoptosis in colorectal cancer cells via disruption of mitochondrial integrity. The cryo-induced apoptosis was also identified in a nude mouse tumor xenograft model. Our elucidation of the apoptosis pathway induced by cryo-injury implies that synergistic combination of cryosurgery with pharmacological agents that augment of apoptosis induction may have clinical relevance in treating colorectal liver metastasis.