Improving the quality of the surgical morbidity and mortality conference: a prospective intervention study

PURPOSE

Surgical morbidity and mortality conferences (M&MCs) provide surgeons with an opportunity to confront medical errors, discuss adverse events, and learn from their mistakes. Yet, no standardized format for these conferences exists. The authors hypothesized that introducing a standardized presentation format using a validated framework would improve presentation quality and educational outcomes for all attendees.

METHOD

Following a review of the literature and the solicitation of experts' opinions, the authors adapted a validated communication tool-the SBAR (Situation, Background, Assessment, Recommendations) framework. In 2010, they then introduced this novel standardized presentation format into the surgical M&MCs at the Oregon Health & Science University. The authors assessed three outcome measures--user satisfaction, presentation quality, and education outcomes--before and after implementation of their standardized presentation format.

RESULTS

Over the six-month study period, residents delivered 66 presentations to 197 faculty, resident, and medical student attendees. Attendees' performance on the multiple-choice questionnaires improved after the intervention, indicating an improvement in their knowledge. Presentation quality also improved significantly after the intervention, according to evaluations by trained faculty assessors. They noted specific improvements in the quality of the Background, Assessment, and Recommendation sections.

CONCLUSIONS

The M&MC plays a pivotal role in educating residents and improving patient safety. Standardizing the M&MC presentation format using an adapted SBAR framework improved the quality of residents' presentations and attendees' educational outcomes. The authors recommend using such a standardized presentation format to enhance the educational value of M&MCs, with the goal of improving surgeons' knowledge, skills, and patient care practices.

Symptomatic venous thromboembolism after femoral vein harvest

OBJECTIVE

The femoral vein is increasingly utilized as a conduit in major arterial and venous reconstruction. However, perioperative complications, especially venous thromboembolism (VTE) associated with femoral vein harvest (FVH), are not well described. The purpose of this study was to determine the incidence and risk factors for the development of symptomatic VTE in patients who undergo FVH.

METHODS

We conducted a retrospective cohort study of all patients who underwent FVH over a 5-year period at a single institution. Patient clinical characteristics, indications for surgery, postoperative venous duplex scans, and computerized tomography scans of the chest were gathered and reviewed from an electronic medical record query. Statistical analysis was performed to determine which factors correlate with development of perioperative complications after FVH.

RESULTS

There were 57 patients (53% male; mean age, 62 years) who underwent 58 FVHs. Of the procedures, 53% were performed for arterial reconstruction and 47% for vascular reconstruction after cancer resection (85% portomesenteric reconstruction). Perioperative VTEs were diagnosed in 17 of 58 (29%) FVH procedures. Sixteen ipsilateral deep vein thromboses (DVTs) occurred distal to the FVH site and five (9%) occurred proximal to the FVH site. The incidence of VTE was significantly greater in patients with malignancy (52% vs 10%; P = .001), and 88% of all VTEs in this series were diagnosed in patients with cancer. All DVTs proximal to the FVH site and all DVTs in the contralateral extremity occurred in patients with malignancy. Pulmonary embolism occurred in two patients. No patients developed compartment syndrome or limb loss. Eight patients (14%) required FVH site wound debridement.

CONCLUSIONS

VTE after FVH occurs more frequently in patients with malignancy. Aggressive and prolonged thromboprophylaxis and routine venous ultrasound surveillance are warranted after FVH in patients with malignancy.

Peripherally inserted central catheter usage patterns and associated symptomatic upper extremity venous thrombosis

OBJECTIVES

Peripherally inserted central catheters (PICCs) may be complicated by upper extremity (UE) superficial (SVT) or deep venous thrombosis (DVT). The purpose of this study was to determine current PICC insertion patterns and if any PICC or patient characteristics were associated with venous thrombotic complications.

METHODS

All UE venous duplex scans during a 12-month period were reviewed, selecting patients with isolated SVT or DVT and PICCs placed ≤30 days. All UE PICC procedures during the same period were identified from an electronic medical record query. PICC-associated DVTs, categorized by insertion site, were compared with all first-time UE PICCs to determine the rate of UE DVT and isolated UE SVT. Technical and clinical variables in patients with PICC-associated UE DVT also were compared with 172 patients who received a PICC without developing DVT (univariable and multivariable analysis).

RESULTS

We identified 219 isolated UE SVTs and 154 UE DVTs, with 2056 first-time UE PICCs placed during the same period. A PICC was associated with 44 of 219 (20%) isolated UE SVTs and 54 of 154 UE DVTs (35%). The rates of PICC-associated symptomatic UE SVT were 1.9% for basilic, 7.2% for cephalic, and 0% for brachial vein PICCs. The rates of PICC-associated symptomatic UE DVT were 3.1% for basilic, 2.2% for brachial, and 0% for cephalic vein PICCs (χ(2)P < .001). Univariate analysis of technical and patient variables demonstrated that larger PICC diameter, noncephalic insertion, smoking, concurrent malignancy, diabetes, and older age were associated with UE DVT (P < .05). Multivariable analysis showed larger catheter diameter and malignancy were the only variables associated with UE DVT (P < .05).

CONCLUSIONS

The incidence of symptomatic PICC-associated UE DVT is low, but given the number of PICCs placed each year, they account for up to 35% of all diagnosed UE DVTs. Larger-diameter PICCs and malignancy increase the risk for DVT, and further studies are needed to evaluate the optimal vein of first choice for PICC insertion.

Techniques and results of portal vein/superior mesenteric vein reconstruction using femoral and saphenous vein during pancreaticoduodenectomy

BACKGROUND

Patients with pancreatic tumors may have portal vein (PV) and/or superior mesenteric vein (SMV) invasion. In such cases, lower extremity veins can provide an autogenous conduit for PV/SMV reconstruction. Little data exist, however, describing the technique of PV/SMV reconstruction, patency of such reconstructions, and the morbidity of using lower extremity veins for PV/SMV reconstruction during pancreaticoduodenectomy.

METHODS

Thirty-four patients underwent PV/SMV reconstruction during pancreaticoduodenectomy using lower extremity vein. The saphenous vein was preferred for patching and femoral vein for replacement. We analyzed preoperative imaging, reconstruction patency, vein harvest morbidity, and late mortality.

RESULTS

The mean age was 62.6 years. All 34 patients had preoperative computed tomography (CT) imaging and/or endoscopic ultrasound (EUS) scan. Fourteen of the 34 patients had evidence of PV/SMV invasion on CT or EUS scans, 14 did not, and six studies were indeterminate. Twenty-five patients had follow-up imaging, and 22 (88%) had patent reconstructions. Fifteen patients had PV/SMV replacement using femoral vein. Seven of these 15 had minor postoperative lower extremity edema that resolved over time, five had wound complications from the femoral vein harvest site, three of which required minor operative procedures for treatment. Fifteen patients had PV/SMV patching with the great saphenous vein, none had postoperative wound problems, and one had minimal postoperative lower extremity edema. Four patients had PV/SMV patching using femoral vein, none had postoperative wound problems, and one had minimal postoperative lower extremity edema. Compared with patients undergoing pancreaticoduodenectomy without PV/SMV reconstruction, by Kaplan-Meier analysis, there was no difference in late mortality.

CONCLUSION

Preoperative imaging may fail to detect PV/SMV involvement in patients undergoing pancreaticoduodenectomy. The PV/SMV reconstruction with leg vein provides good patency with minimal postoperative lower extremity complications and no increase in late mortality. The lower extremities should be routinely included in the operative field of patients undergoing pancreaticoduodenectomy.

Circadian clock resetting by behavioral arousal: neural correlates in the midbrain raphe nuclei and locus coeruleus

Some procedures for stimulating arousal in the usual daily rest period (e.g., gentle handling, novel wheel-induced running) can phase shift circadian rhythms in Syrian hamsters, while other arousal procedures are ineffective (inescapable stress, caffeine, modafinil). The dorsal and median raphe nuclei (DRN, MnR) have been implicated in clock resetting by arousal and, in rats and mice, exhibit strong regionally specific responses to inescapable stress and anxiogenic drugs. To examine a possible role for the midbrain raphe nuclei in the differential effects of arousal procedures on circadian rhythms, hamsters were aroused for 3 h in the mid-rest period by confinement to a novel running wheel, gentle handling (with minimal activity) or physical restraint (with intermittent, loud compressed air stimulation) and sacrificed immediately thereafter. Regional expression of c-fos and tryptophan hydroxylase (TrpOH) were quantified immunocytochemically in the DRN, MnR and locus coeruleus (LC). Neither gentle handling nor wheel running had a large impact on c-fos expression in these areas, although the manipulations were associated with a small increase in c-Fos in TrpOH-like and TrpOH-negative cells, respectively, in the caudal interfascicular DRN region. By contrast, restraint stress significantly increased c-Fos in both TrpOH-like and TrpOH-negative cells in the rostral DRN and LC. c-Fos-positive cells in the DRN did not express tyrosine hydroxylase. These results reveal regionally specific monoaminergic correlates of arousal-induced circadian clock resetting, and suggest a hypothesis that strong activation of some DRN and LC neurons by inescapable stress may oppose clock resetting in response to arousal during the daily sleep period. More generally, these results complement evidence from other rodent species for functional topographic organization of the DRN.

Favorable early outcomes for patients with extended indications for thoracic endografting

BACKGROUND

Endografts originally designed and approved for the treatment of thoracic aortic aneurysms have rapidly been adopted for nonapproved use in the treatment of disorders of the thoracic aorta, including aortic transection, dissection, pseudoaneurysms, and thoracoabdominal aneurysms. The purpose of this study was to evaluate the early outcomes of patients treated with thoracic endografts for nonapproved indications at our institution.

METHODS

The medical records of patients undergoing thoracic endografting at our institution from August 2005 until March 2008 were reviewed. Patients undergoing endografting for uncomplicated thoracic aortic aneurysms were excluded. The outcomes of patients with extended indications for thoracic endografting were studied.

RESULTS

During the study period, endografting was performed in 31 patients for nonapproved aortic conditions. Patients underwent endografting for a spectrum of indications, including aortic transection (n = 12), complications of type B aortic dissection including rupture (n = 9), thoracoabdominal aneurysm with visceral debranching (n = 6), aortic arch debranching (n = 2), and pseudoaneurysm associated with prior coarctation repair (n = 2). Early outcomes were favorable. All patients had successful endograft repair of their anatomic lesion. There were no endoleaks. There was no hospital mortality. Average hospitalization was 15 days for patients with aortic transection and 9 days for all other patients.

CONCLUSIONS

Thoracic endografts are versatile devices that with appropriate expertise can be used effectively to treat a spectrum of disorders of the thoracic aorta, including acute emergencies. Early outcomes of patients with extended indications for thoracic endografting compare favorably to published series of patients treated with open procedures. Further study is required to assess the long-term efficacy of these devices.

Factors Affecting Symptomatic vs Asymptomatic Vein Graft Stenoses in Lower Extremity Bypass Grafts

OBJECTIVE

To determine differences in patients undergoing lower extremity vein graft revisions presenting with and without recurrence of preoperative symptoms.

DESIGN

Retrospective case-control study of a prospectively maintained database.

SETTING

University and veterans' administration hospitals

PATIENTS

Two hundred nineteen lower extremity vein graft revisions were performed in 161 patients from January 1995 to January 2007. Patients were categorized as asymptomatic or symptomatic (recurrence of initial symptoms) at the time of revision.

MAIN OUTCOME MEASURES

Univariate analysis was performed to assess differences in patient demographics, details of initial operation, site of recurrent lesion, and follow-up surveillance data between symptomatic and asymptomatic patients. Independent predictors of symptomatic recurrence were identified with multivariate logistic regression. Primary assisted patency was compared between revisions performed for symptomatic and asymptomatic lesions.

RESULTS

Vein graft stenoses were asymptomatic in 125 cases (57%) and symptomatic in 94 cases (43%). Symptomatic recurrences were associated with a significantly greater drop in ankle brachial index than asymptomatic lesions (mean [SD], 0.21 [0.03] vs 0.11 [0.02]; P = .003). Distal graft or outflow lesions were significantly associated with symptom recurrence (P = .048). Multivariate analysis identified ankle brachial index decrease (odds ratio, 6.803; 95% confidence interval, 1.418-32.258; P = .02) and the use of alternate graft conduit (odds ratio, 2.633, 95% confidence interval, 1.243-5.578; P = .01) as independent predictors of recurrent symptoms. Overall 5-year patency was the same regardless of preoperative symptoms (82% symptomatic and 88% asymptomatic; P = .30).

CONCLUSIONS

Symptomatic recurrences are associated with larger decreases in ankle brachial index, distal lesions, and alternate conduit grafts. Duplex surveillance is necessary to identify asymptomatic vein graft stenoses. Because graft patency is independent of preoperative symptoms, surveillance consisting of clinical follow-up with ankle brachial index evaluation warrants further consideration.

Functional outcome of critical limb ischemia

Results of treatment for critical limb ischemia have traditionally focused on physician-oriented end points related to limb salvage surgery. Although numerous studies have demonstrated excellent patency and limb salvage after surgical revascularization procedures, survival in this patient population is poor, comorbidities reducing quality of life are rampant, and recovery from limb salvage surgery can be prolonged and complicated despite "success" as defined by traditional reporting methods. Patient-oriented outcome end points, such as health- related quality of life and functional status, are essential in defining optimal treatment options for the population of patients with critical limb ischemia. This area of research remains in its infancy, but will become increasingly important as the population of patients with critical limb ischemia and treatment options for these patients continue to expand. The current status and future outlook of functional and quality of life assessment of patients with critical limb ischemia is reviewed.

Robust food anticipatory circadian rhythms in rats with complete ablation of the thalamic paraventricular nucleus

Rats can anticipate a fixed daily mealtime by entrainment of a circadian timekeeping mechanism anatomically separate from the light-entrainable circadian pacemaker located in the suprachiasmatic nucleus. Neural substrates of this food-entrainable circadian system have not yet been fully elucidated. A role for the thalamic paraventricular nucleus (PVT) is suggested by observations that scheduled feeding synchronizes daily rhythms of glucose utilization and immediate early gene and circadian clock gene expression in this area. One study has reported absence of food anticipatory circadian activity rhythms in rats with PVT ablations. To determine whether this effect extends to other behavioral measures of food anticipation, rats received large radiofrequency lesions aimed at the PVT and were maintained on a 3-h meal provided each day 6 h after lights-on. Rats with unambiguously complete PVT ablation exhibited increased total daily activity, a change in the waveform of the nocturnal activity rhythm, but no change in the amplitude, duration, latency to appearance or persistence during total food deprivation of food anticipatory activity measured by activity at or near a food bin accessible via a small window in the recording cage. These results indicate that, while the PVT may modulate light-entrainable rhythms, it is not a critical input, oscillator or output component of the circadian system by which rats behaviorally anticipate a daily mealtime.

Prospective evaluation of the relationship between C-reactive protein, D-dimer and progression of peripheral arterial disease

OBJECTIVE

Elevated levels of C-reactive protein (CRP) and D-dimer (DD) have been associated with the presence and progression of various forms of atherosclerotic disease, particularly coronary heart disease. We hypothesize that there is a relationship between elevated levels of baseline CRP and DD and progression of peripheral arterial disease (PAD) in patients with symptomatic PAD. The current study is a prospective evaluation of this hypothesis.

METHODS

Between 1996 and 2003, 384 subjects were enrolled in a National Institutes of Health-sponsored blinded, prospective trial evaluating the effects of multiple atherosclerotic risk factors on progression of symptomatic PAD. Baseline levels of CRP and D-dimer were obtained in 332 subjects. Subjects were followed every 6 months with clinical history and exam, ankle-brachial pressure index (ABI), and carotid artery duplex scanning (CDS). The primary study end point was a composite of ABI progression, CDS progression, stroke, myocardial infarction, amputation, and death from cardiovascular disease. Secondary end points included each of the components of the primary end point. The relationship between time to the various endpoints and baseline CRP and DD levels was examined by life-table analysis and Cox proportional hazards analysis.

RESULTS

Adequate baseline samples for CRP and DD were available in 332 subjects (mean age, 67 years; 57.8% men) with mean follow-up of 38.4 months (range, 1 to 99 months). Mean baseline levels (+/- SD) for CRP were 0.8 +/- 1.14 (range, 0.03 to 13.0), and mean DD levels were 227.4 +/- 303.3 (range, 1.9 to 2744.8). Progression, as defined by the primary end point, occurred in 48.5% of subjects. Subjects with elevated CRP (highest tertile) were no more likely to have any of the progression end points than those with the lowest values (lowest tertile) (P = NS, log-rank test, for all comparisons). By univariate analysis, subjects with elevated DD (highest tertile) were significantly more likely to die from any cause compared with subjects with the lowest DD values (lowest tertile) (P = .03, log-rank test). They were, however, no more likely to reach any of the other progression end points, including the primary end point (P = NS, log-rank test for all other comparisons). Multivariate analysis showed that DD level was a significant independent variable associated with occurrence of myocardial infarction (hazard ratio, 2.3; P = .02).

CONCLUSIONS

In subjects with symptomatic PAD, elevated baseline DD, a marker of thrombotic activity, was significantly associated with the occurrence of myocardial infarction. This study did not confirm a relationship between progression of PAD and baseline DD or CRP during the first 3 years. Baseline DD and CRP do not provide useful risk stratification in patients at high risk for progression of symptomatic PAD. Future studies should evaluate serial levels of these markers to assess their utility in predicting progression of symptomatic PAD.

Persistence of a behavioral food-anticipatory circadian rhythm following dorsomedial hypothalamic ablation in rats

Circadian rhythms of behavior in rodents are regulated by a system of circadian oscillators, including a master light-entrainable pacemaker in the suprachiasmatic nucleus that mediates synchrony to the day-night cycle, and food-entrainable oscillators located elsewhere that generate rhythms of food-anticipatory activity (FAA) synchronized to daily feeding schedules. Despite progress in elucidating neural and molecular mechanisms of circadian oscillators, localization of food-entrainable oscillators driving FAA remains an enduring problem. Recent evidence suggests that the dorsomedial hypothalamic nucleus (DMH) may function as a final common output for behavioral rhythms and may be critical for the expression of FAA (Gooley JJ, Schomer A, and Saper CB. Nat Neurosci 9: 398-407, 2006). To determine whether the reported loss of FAA by DMH lesions is specific to one behavioral measure or generalizes to other measures, rats received large radiofrequency lesions aimed at the DMH and were recorded in cages with movement sensors. Total and partial DMH ablation was associated with a significant attenuation of light-dark-entrained activity rhythms during ad libitum food access, because of a selective reduction in nocturnal activity. When food was restricted to a single 3-h daily meal in the middle of the lights-on period, all DMH and intact rats exhibited significant FAA. The rhythm of FAA persisted during a 48-h food deprivation test and reappeared during a 72-h deprivation test after ad libitum food access. The DMH is not the site of oscillators or entrainment pathways necessary for all manifestations of FAA, but may participate on the output side of this circadian function.

Iatrogenic arterial injury is an increasingly important cause of arterial trauma

BACKGROUND

Iatrogenic arterial injuries (IAI) may result from any invasive diagnostic or therapeutic procedure. The relative occurrence and severity of IAI compared with those of penetrating and blunt vascular trauma is unknown. A review of arterial trauma at a university hospital level 1 trauma center, with a focus on iatrogenic injury, forms the basis of this report.

METHODS

Patients treated for arterial trauma from January 1994 through October 2002 were identified from prospectively maintained registries. Record review included injury etiology, type of repair, 30-day all-cause mortality, and permanent morbidity. Permanent morbidity was defined as amputation or loss of extremity function.

RESULTS

In all, 252 patients required treatment, 85 (33.7%) from IAI, 86 (34.1 %) from penetrating trauma, and 81 (32.1%) from blunt trauma. During the study period, the number of IAIs per year increased. Femoral artery injury from percutaneous intervention (50, 58.8%) was the most frequent IAI; intraoperative injury (including 14 tumor resections and 5 orthopedic procedures) was next most frequent (23, 27.1%). Three patients (3.5%) with IAI had permanent morbidity. The 30-day all-cause mortality was 7.1% (6) for patients with IAI.

CONCLUSIONS

Iatrogenic arterial injury is increasingly frequent and caused one third of the arterial trauma at our level 1 trauma center. These data suggest education and training regarding IAI deserves equal priority with the study of penetrating vascular trauma.

Risk factors for autogenous infrainguinal bypass occlusion in patients with prosthetic inflow grafts

OBJECTIVE

In patients with prosthetic inflow (PI) grafts the proximal anastomosis of autogenous infrainguinal bypass (AIB) can be placed on the PI or on a distal native vessel in the groin. This study was performed to determine the effect of placement of an AIB proximal anastomotic site in a patient with ipsilateral PI.

METHODS

Patients undergoing AIB and PI between January 1990 and July 2002 were included in the study. They were classified into two groups on the basis of location of the proximal anastomosis. In group 1 the AIB proximal anastomosis was placed on the PI in the groin, whereas in group 2 the AIB proximal anastomosis was placed on a distal native groin artery. Patency, limb salvage, and patient survival in the two groups were calculated with the Kaplan-Meier method. The Cox proportional hazards model was used to determine independent risk factors affecting AIB patency.

RESULTS

Two hundred twenty-nine patients underwent AIB and PI. In group 1, 23 AIBs became thrombosed concurrent with 26 PI occlusions, and in group 2, 7 AIBs became thrombosed concurrent with 36 PI occlusions (P <.001). Five-year assisted primary patency, limb salvage, and patient survival in groups 1 and 2 were 50% and 75% (P <.001, log-rank test), 78% and 90% (P =.005, log-rank test), and 56% and 69% (P = NS, log-rank test), respectively. Factors independently associated with AIB occlusion are hypertension (hazard ratio [HR], 3.41; 95% confidence interval [CI], 1.65-7.05; P =.001), postoperative warfarin sodium therapy (HR, 1.86; 95% CI, 1.07-3.23; P =.03), continued smoking (HR, 1.72; 95% CI, 0.93-3.18; P =.08), AIB arising from PI (HR, 2.38; 95% CI, 1.35-4.18; P =.003), and PI occlusion (HR, 3.70; 95% CI, 2.15-6.36; P <.001).

CONCLUSION

A proximal AIB anastomosis located directly on the PI is an independent risk factor for decreased AIB patency of equal or greater importance than current smoking, hypertension, or PI occlusion. The proximal anastomosis of an AIB in a patient with an ipsilateral PI should be placed on a distal native artery.

Comparison of procedural outcomes after lower extremity reversed vein grafting and secondary surgical revision

OBJECTIVE

Many lower extremity vein graft procedures require revision. Although morbidity associated with revision procedures is assumed minimal, this has not been previously quantified and may be underestimated. In this study, patient outcome after initial vein graft procedures and revisions are compared.

METHODS

Records for all patients undergoing vein graft revision from January 1995 to August 2002 were reviewed for operation time, estimated blood loss, blood transfusion, hospital length of stay, perioperative complications, and functional status at discharge and at 2-month follow-up. Revisions were compared with the original operation and by revision type.

RESULTS

One hundred sixty-five vein graft revisions were performed in 137 patients. In comparison with the initial bypass procedure, mean operation time (3.35 +/- 1.41 hours vs 2.58 +/- 1.04 hours; P <.001), estimated blood loss (272.4 +/- 249.9 mL vs 174.8 +/- 140.8 mL; P <.001), hospital length of stay (10.15 +/- 4.85 days vs 7.05 +/- 5.14; P <.001), and overall complication rate (35.8% vs 22.4%; P =.015) were significantly less for revision procedures. Revision of more than one site on the graft resulted in longer operation time (P =.003) and estimated blood loss (P <.001), but similar complication rates (P = NS), compared with revision at only one site. Revisions that involved only the graft resulted in decreased hospital length of stay compared with revisions involving extension to native inflow or outflow vessels (P <.02). Return to preoperative ambulatory status at discharge was 71% after initial operation, and was 92% after revision (P <.001). Return to independent living at discharge was 66% after the initial operation, and was 80% after revision (P <.01).

CONCLUSIONS

Operative revisions were better tolerated than initial vein graft procedures, but are still major procedures. Hospital length of stay is longer for patients undergoing proximal or distal extension of the graft to native vessels and in patients who are not ambulatory and living independently at discharge. Patients undergoing vein graft revision should be counseled about potential morbidity.

Modifiable patient factors are associated with reverse vein graft occlusion in the era of duplex scan surveillance

OBJECTIVE

Modifiable patient factors that contribute to graft occlusion may be addressed after surgery. To determine risk factors associated with reverse vein graft (RVG) occlusion, we examined the characteristics and duplex scan surveillance (DS) patterns of patients with RVGs.

METHODS

Patients treated with RVG from January 1996 through December 2000 were identified from a prospective registry. The study population consisted of all patients with RVGs performed during the study period with grafts that subsequently occluded. Patients whose grafts remained patent served as age-matched and gender-matched control subjects. The prescribed DS regimen was every 3 months for the first postoperative year and every 6 months thereafter. Early DS failure was defined as having no DS within the first 3 months. Cox proportional hazards analysis was used to compare the two groups. Hazard ratios were calculated.

RESULTS

During the study period, 674 patients underwent RVG. Fifty-five patients with occluded RVGs were compared with 118 with patent RVGs. The follow-up period for occluded grafts was 13.40 +/- 12.59 months and for patent grafts was 32.40 +/- 15.61 months. Dialysis therapy, a known hypercoagulable state, continued smoking, and DS failure were independent factors associated with RVG occlusion. The hazards ratio for dialysis was 6.45 (95% CI, 3.07 to 13.51; P <.001), for current smoking was 4.72 (95% CI, 2.5 to 8.85; P <.001), for hypercoagulable state was 2.99 (95% CI, 1.47 to 6.10; P =.003), and for early DS failure was 2.43 (95% CI, 1.29 to 4.59; P =.006).

CONCLUSION

Continued smoking and failure to undergo DS within the first three postoperative months are modifiable factors associated with RVG occlusion. Smoking cessation and graft surveillance must be stressed to optimize patency of infrainguinal RVGs.

Postoperative duplex scan surveillance of axillofemoral bypass grafts

OBJECTIVE

Duplex scan surveillance (DS) for axillofemoral bypass grafts (AxFBGs) has not been extensively studied. The intent of this study was twofold: 1, to characterize the flow velocities within AxFBGs; and 2, to determine whether postoperative DS is useful in assessment of future patency of AxFBGs.

METHODS

We identified all patients who underwent AxFBG procedures between January 1996 and January 2001 at our combined university and Veterans Affairs hospital vascular surgical service. All grafts were performed with ringed 8-mm polytetrafluoroethylene with the distal limb of the axillofemoral component anastomosed to the hood of the femoral-femoral graft. DS was every 3 months for 1 year and every 6 months thereafter. Duplex scan results were compared in primarily patent grafts with grafts that thrombosed. Graft failures from infection were excluded. Influences of ankle-brachial index, blood pressure, outflow patency, operative indication, and comorbidities on graft patency were analyzed.

RESULTS

One hundred twenty patients underwent AxFBG procedures. Twenty-eight were excluded because of infection or death before surveillance examination. Fourteen were lost to follow-up, 23 had failed grafts from occlusion, and 55 had grafts that remained patent. In the 78 patients evaluated during long-term follow-up period, the mean peak systolic velocities (PSVs) at the proximal (axillary) anastomosis during the first postoperative year ranged from 153 to 194 cm/s. Mean PSVs at the mid portion of the axillofemoral graft during the first postoperative year ranged from 100 to 125 cm/s, whereas those for the distal axillofemoral anastomosis ranged from 93 to 129 cm/s. Mean midgraft and distal anastomotic velocities obtained before thrombosis were significantly lower in the thrombosed grafts compared with the last recorded velocities at the same sites in the patent grafts (mean PSV, 84 versus 112 cm/s; P =.015; mean PSV, 89 versus 127 cm/s; P =.024, respectively). Forty-eight percent of occluded grafts had a mean midgraft PSV at last observation of less than 80 cm/s. Blood pressure correlated with midgraft velocity (r = 0.415; P <.05). With multivariate logistic regression analysis, a mean midgraft velocity less than 80 cm/s was the sole independent factor associated with graft failure (P <.01). No patients with midgraft velocities greater than 155 cm/s had occlusion.

CONCLUSION

Flow velocity varies widely within and among AxFBGs. Patency of AxFBGs is associated with higher midgraft PSV, and thrombosis with midgraft velocities less than 80 cm/s.

Repeat axillofemoral grafting as treatment for axillofemoral graft occlusion

BACKGROUND

Patency of failed axillofemoral (ax-fem) grafts following thrombectomy is so poor, aortofemoral grafts are recommended as treatment for ax-fem graft thrombosis. In patients who are not candidates for aortic grafting, repeat ax-fem grafting is an alternative to thrombectomy. This report compares our experience treating ax-fem graft thrombosis with replacement or revision vs thrombectomy.

METHODS

Patients treated with ax-fem grafts from October 1985 to April 2001 were identified, and those who underwent reoperation for thrombosis were reviewed. Limb salvage and patency of revision procedures (thrombectomy vs repeat ax-fem grafting) were determined using Kaplan-Meier curves.

RESULTS

Three hundred thirty-five patients underwent ax-fem grafting, and 39 (11.6%) of the 335 required reoperation for graft failure. Twenty-five of these 39 patients had 51 operations for graft thrombosis: 42 graft replacements and/or anastomotic revision(s), and 9 thrombectomies. At 18 months, mean +/- SD patency following thrombectomy was 11% +/- 10%, while that for graft replacement or anastomotic revision was 54% +/- 8% (P<.001). Limb salvage at 18 months following revision for thrombosis was 88% +/- 5%.

CONCLUSIONS

The large majority of ax-fem grafts do not require reoperation. For failure due to thrombosis, repeat ax-fem grafting provides excellent limb salvage. Axillofemoral graft replacement and/or anastomotic revision has superior patency to thrombectomy.

Relationship of hemodialysis access to finger gangrene in patients with end-stage renal disease

OBJECTIVE

We report a comprehensive review of our patients on hemodialysis with end-stage renal disease (ESRD) with finger gangrene to determine etiology, natural history, and prognosis of this condition.

METHODS

Patients with ESRD with finger gangrene were identified from our computerized vascular registry. Presence of an ipsilateral arteriovenous fistula was determined, and patients were compared with a group of patients with ESRD without finger gangrene. Management consisted of arteriography, selective arteriovenous fistula management, and finger amputation. A multivariate analysis to determine risk factors associated with finger gangrene was performed. Repeat finger amputation and survival rates were determined with life-table analysis.

RESULTS

Twenty-three patients (mean age at start of dialysis, 53 years) with finger gangrene were identified, with 48% (n = 11) having a functional ipsilateral arteriovenous fistula. Arteriography was consistent with diffuse atherosclerosis involving the radial, ulnar, palmar, and digital arteries precluding attempts at distal arterial bypass. Repeat finger amputations were necessitated in 52% of patients (n = 12), and bilateral finger gangrene developed in 61% of patients (n = 14). Starting dialysis at age less than 55 years (P =.0004), diabetes (P =.001), coronary artery disease (P =.0212), and lower extremity arterial occlusive disease (P <.0001) were significantly associated with finger gangrene.

CONCLUSION

The young diabetic patient with diffuse vascular disease and ESRD is at high risk for the development of finger gangrene on chronic hemodialysis. Finger gangrene is the result of distal atherosclerosis and is not primarily related to dialysis access.

Choice of autogenous conduit for lower extremity vein graft revisions

BACKGROUND

Surgical revision to repair stenosis is necessary in about 20% of lower extremity vein grafts (LEVGs). Alternate conduit, especially arm vein, is often necessary to achieve a policy of all-autogenous revisions. Although basilic vein harvest necessitates deep exposure in proximity to major nerves, it typically uses a large vein unaffected by prior intravenous lines and as such appears ideally suited for revisions in which a segmental interposition conduit is needed for revision within the graft or for extension to a more proximal inflow or distal outflow site. In this report, we describe our experience with the use of the basilic vein for LEVG revisions compared with other sources of autogenous conduit.

METHODS

All patients who underwent LEVG were placed in a duplex scan surveillance program. LEVGs that developed a focal area of increased velocity or uniformly low velocities throughout the graft with appropriate lesions confirmed with angiography were candidates for revision. All patients who underwent graft revision with basilic vein segments from January 1, 1990, to September 1, 2001, were identified, and their courses were reviewed for subsequent adverse events (further revision or occlusion) and complications of harvest. These revisions were compared with revisions in which cephalic and saphenous vein were used.

RESULTS

One hundred thirty basilic veins were used to revise 122 LEVGs. The mean follow-up period after revision was 28 +/- 27 months. Ninety-three grafts (71%) remained patent with no further revision, and 37 grafts (29%) either needed additional revisions (22 grafts) or were occluded (15 grafts). Only four of these adverse events (11%) were directly attributed to the basilic vein segment. Ten of 43 grafts revised with cephalic vein (23%) were either revised or occluded, of which three were related to the cephalic vein segment (P = not significant, compared with basilic vein). Twenty-four of 81 grafts revised with saphenous vein (30%) were either revised or occluded, of which 11 were attributed to the saphenous vein segment (P <.01, compared with basilic vein). Two patients (1.5%) had complications from basilic vein harvest (one hematoma, one arterial injury). No neurologic injuries resulted from basilic vein harvest.

CONCLUSION

The basilic vein is a reliable and durable conduit when used to segmentally revise LEVGs. Stenoses rarely occur within interposed basilic vein segments, and excellent freedom from subsequent revision or occlusion is possible. We conclude the basilic vein can be safely harvested with minimal complications and is ideally suited for use as a short segment interposition graft for LEVG revision.

Homocysteine and arterial disease. Experimental mechanisms

Hyperhomocysteinemia (hH(e)) in the general population is associated with incidence and progression of arterial occlusive disease, although the underlying mechanisms are not well defined. Current research supports a role for homocysteine (H(e))-mediated endothelial damage and endothelial dysfunction. This mechanism appears to be a key factor in subsequent impaired endothelial-dependent vasoreactivity and decreased endothelium thromboresistance. These consequences may predispose hyperhomocysteinemic vessels to the development of increased atherogenesis. Additional mechanisms of H(e)-mediated vascular pathology, including protein homocysteinylation and vascular smooth muscle cell proliferation may also play a role. Continued investigation into the mechanisms contributing to H(e) toxicity will provide further insight into the processes by which hH(e) may increase atherosclerosis.