Revision der CEAP-Klassifizierung für chronische Venenleiden

Die CEAP-Klassifizierung für chronische Venenleiden wurde 1994 durch ein internationales Ad-hoc-Komitee des American Venous Forum entwickelt, durch die Society for Vascular Surgery unterstützt und 1995 in die „Reporting Standards in Venous Disease“ inkorporiert. Inzwischen benutzen die meisten publizierten klinischen Arbeiten das CEAPSystem, ganz oder in Teilen.

Um die Klassifizierung nicht als statisches System zu belassen, hat ein Ad-hoc-Komitee des American Venous Forum in Zusammenarbeit mit einem internationalen Verbindungskomitee eine Reihe von praktischen Änderungen empfohlen, die in diesem Konsensusbericht aufgelistet sind. Diese beinhalten eine Verfeinerung verschiedener Definitionen, welche der Beschreibung von chronischen Venenerkrankungen dienen, eine Verfeinerung der C-Klassen von CEAP, der Zusatz der Beschreibung n (no venous abnormality), das Datum der Klassifizierung, die Untersuchungsstufe sowie, als einfachere Alternative zur vollen (fortgeschrittenen) CEAP-Klassifizierung, die Einführung einer Basis-CEAP-Version. Es ist wichtig, darauf hinzuweisen, dass CEAP eine deskriptive Klassifizierung darstellt, wogegen das „Venous severity scoring“ sowie Lebensqualitäts- Scores Instrumente für longitudinale Outcome-Studien darstellen.

Role of matrix metalloproteinases 1, 2, and 9 and tissue inhibitor of matrix metalloproteinase-1 in chronic venous insufficiency

PURPOSE

Increased transforming growth factor-beta(1) (TGF-beta(1)) activity is associated with chronic venous insufficiency (CVI) disease progression and dermal skin pathology. Because TGF-beta(1) stimulates collagen synthesis and alters the levels of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs), we investigated the hypothesis that increased TGF-beta(1) activity is associated with differences in messenger RNA and protein levels of MMPs and TIMP-1 in patients with CVI.

METHODS

One hundred ten biopsies of the lower calf and lower thigh in 73 patients were snap frozen in liquid nitrogen and stratified into six groups according to the clinical etiologic anatomic distribution pathophysiology disease classification. One set of lower-calf and lower-thigh biopsies were analyzed for MMP-1 and TIMP-1 gene expression with quantitative reverse transcription and competitive polymerase chain reaction. A second set of biopsies was analyzed for the active and latent forms of MMP-1, MMP-2, and MMP-9 as well as for TIMP-1 by western blotting, gelatin zymography, and tissue localization by immunohistochemistry (IHC).

RESULTS

Compared with the control, MMP-1 messenger RNA was increased in class-4 and class-6 patients (P < or =.01), whereas TIMP-1 was increased in class-6 patients only (P < or =.05). However, there were no differences in total protein between MMP-1 and TIMP-1. Active MMP-2 protein increased in class-4 and class-5 patients compared with active MMP-1 and TIMP-1 (P < or =.01). Western blotting did not identify the active component of MMP-9. Similarly, only the latent form of MMP-9 was observed by gelatin zymography, whereas both the latent and active forms of MMP-2 were observed. IHC demonstrated MMP-1 and MMP-2 in dermal fibroblasts and in perivascular leukocytes. TIMP-1 was observed in basal-layer keratinocytes of the epidermis only. MMP-9 was not detected by IHC.

CONCLUSION

MMP synthesis is regulated at both the transcriptional and post-transcriptional levels in CVI. Our data suggest that post-translational modifications are key to functional regulation. Dermal fibroblasts and migrating leukocytes are probable cellular sources of MMPs. Increased active MMP-2 levels in class-4 and class-5 patients indicate tissue remodeling caused by pre-ulcer and postulcer environmental stimuli. These data suggest that alterations in MMP-2 activity, in conjunction with TGF-beta(1)-mediated events, cause an imbalance in tissue remodeling leading to a pro-ulcer-forming environment.

Survival of nosocomial pathogenic bacteria at ambient temperature

Staphylococcus aureus and many gram-negative rods are prevalent nosocomial pathogens. The mechanisms by which these organisms persist and spread within the hospital environment have not been clearly defined. We found that these bacteria have an extraordinary capability for survival in the environment. The viabilities of staphylococcal and gram-negative (Escherichia coli and Pseudomonas aeruginosa) isolates were assessed on three environmental surfaces: a non-nutrient surface, a woven cotton fiber, and a blood protein coagulum. The bacteria were dried on these surfaces and quantitatively subcultured over six months. The viability was consistently higher on dried blood surfaces. Viability was next highest on cotton strings. For both of these environments, staphylococci appeared to lose viability between three and six months, while E. coli and P. aeruginosa survived longer. Survival on a clean non-nutrient surface (tubes alone) for all organisms was much briefer and did not extend beyond four weeks. Such extended survival on blood and fiber surfaces, as observed in part, explains the difficulty in controlling colonization of patients by and spread of these nosocomial pathogens.

In-stent restenosis after carotid angioplasty-stenting: incidence and management

PURPOSE

Carotid angioplasty-stenting (CAS) has been advocated as an alternative to carotid endarterectomy (CEA) in patients with restenotic lesions after prior CEA, primary stenoses with significant medical comorbidities, and radiation-induced stenoses. The incidence of restenosis after CAS and its management remains ill defined. We evaluated the incidence and management of in-stent restenosis after CAS.

METHODS

Patients with asymptomatic (61%) and symptomatic (39%) carotid stenosis of > or = 80% underwent CAS between September 1996 and May 2000; there were 50 procedures and 46 patients (26 men and 20 women). All patients were followed up clinically and underwent duplex ultrasonography (DU) at 3- to 6-month intervals. In-stent restenoses > or = 80% detected with DU were further evaluated by means of angiography for confirmation of the severity of stenosis.

RESULTS

No periprocedural or late strokes occurred in the 50 CAS procedures during the 30-day follow-up period. One death (2.2%) that resulted from myocardial infarction was observed 10 days after discharge following CAS. During a mean follow-up period of 18 +/- 10 months (range, 1-44 months), in-stent restenosis was observed after four (8%) of the 50 CAS procedures. Angiography confirmed these high-grade (> or = 80%) in-stent restenoses, which were successfully treated with balloon angioplasty (3) or angioplasty and restenting (1). No periprocedural complications occurred, and these patients remained asymptomatic and without recurrent restenosis over a mean follow-up time of 10 +/- 6 months.

CONCLUSIONS

We recommend CAS for post-CEA restenosis, primary stenoses in patients with high-risk medical comorbidities, and radiation-induced stenoses. In-stent restenoses occurred after 8% of CAS procedures and were managed without complications with repeat angioplasty or repeat angioplasty and restenting.

Venous severity scoring: An adjunct to venous outcome assessment

Some measure of disease severity is needed to properly compare the outcomes of the various approaches to the treatment of chronic venous insufficiency. Comparing the outcomes of two or more different treatments in a clinical trial, or the same treatment in two or more reports from the literature cannot be done with confidence unless the relative severity of the venous disease in each treatment group is known. The CEAP (Clinical-Etiology-Anatomic-Pathophysiologic) system is an excellent classification scheme, but it cannot serve the purpose of venous severity scoring because many of its components are relatively static and others use detailed alphabetical designations. A disease severity scoring scheme needs to be quantifiable, with gradable elements that can change in response to treatment. However, an American Venous Forum committee on venous outcomes assessment has developed a venous severity scoring system based on the best usable elements of the CEAP system. Two scores are proposed. The first is a Venous Clinical Severity Score: nine clinical characteristics of chronic venous disease are graded from 0 to 3 (absent, mild, moderate, severe) with specific criteria to avoid overlap or arbitrary scoring. Zero to three points are added for differences in background conservative therapy (compression and elevation) to produce a 30 point-maximum flat scale. The second is a Venous Segmental Disease Score, which combines the Anatomic and Pathophysiologic components of CEAP. Major venous segments are graded according to presence of reflux and/or obstruction. It is entirely based on venous imaging, primarily duplex scan but also phlebographic findings. This scoring scheme weights 11 venous segments for their relative importance when involved with reflux and/or obstruction, with a maximum score of 10. A third score is simply a modification of the existing CEAP disability score that eliminates reference to work and an 8-hour working day, substituting instead the patient's prior normal activities. These new scoring schemes are intended to complement the current CEAP system.

Mandibular subluxation for distal internal carotid exposure: technical considerations

PURPOSE

Carotid endarterectomy (CEA) has become one of the most commonly performed vascular procedures, because of the beneficial outcome it has when compared with medical therapy alone and because of the anatomic accessibility of the artery. In cases of distal carotid occlusive disease, high cervical carotid bifurcation, and some reoperative cases, access to the distal internal carotid artery may limit surgical exposure and increase the incidence of cranial nerve palsies. Mandibular subluxation (MS) is recommended to provide additional space in a critically small operative field. We report our experience to determine and illustrate a preferred method of MS.

METHODS

Techniques for MS were selected based on the presence or absence of adequate dental stability and periodontal disease. All patients received general anesthesia with nasotracheal intubation before subluxation. Illustrations are provided to emphasize technical considerations in performing MS in 10 patients (nine men and one woman) who required MS as an adjunct to CEA (less than 1% of primary CEAs). Patients were symptomatic (n = 7) or asymptomatic (n = 3) and had high-grade stenoses demonstrated by means of preoperative arteriography.

RESULTS

Subluxation was performed and stabilization was maintained by means of: Ivy loop/circumdental wiring of mandibular and maxillary bicuspids/cuspids (n = 7); Steinmann pins with wiring (n = 1); mandibular/maxillary arch bar wiring (n = 1); and superior circumdental to circummandibular wires (n = 1). MS was not associated with mandibular dislocation in any patient. No postoperative cranial nerve palsies were observed. Three patients experienced transient temporomandibular joint discomfort, which improved spontaneously within 2 weeks.

CONCLUSION

Surgical exposure of the distal internal carotid artery is enhanced with MS and nasotracheal intubation. We recommend Ivy loop/circumdental wiring as the preferred method for MS. Alternative methods are used when poor dental health is observed.

Dermal tissue fibrosis in patients with chronic venous insufficiency is associated with increased transforming growth factor-beta1 gene expression and protein production

PURPOSE

Pathologic dermal degeneration in patients with chronic venous insufficiency (CVI) is characterized by aberrant tissue remodeling that results in stasis dermatitis, tissue fibrosis, and ulcer formation. The cytochemical processes that regulate these events are unclear. Because transforming growth factor-beta(1) (TGF-beta(1)) is a known fibrogenic cytokine, we hypothesized that the increased production of TGF-beta(1) would be associated with CVI disease progression.

METHODS

Seventy-eight punch biopsy specimens of the lower calf (LC) and the lower thigh (LT) of 52 patients were snap frozen in liquid nitrogen and stratified into four groups according to the Society for Vascular Surgery/International Society for Cardiovascular Surgery CEAP classification (C, clinical; E, etiologic; A, anatomic distribution; and P, pathophysiology). One set of LC biopsy specimens were analyzed for TGF-beta(1) gene expression with quantitative reverse transcriptase-polymerase chain reaction: healthy skin, n = 6; class 4, n = 6; class 5, n = 5; and class 6, n = 7. A second set of biopsy specimens from the LC and LT were analyzed for the amount of bioactive TGF-beta(1) with a certified cell line 64 mink lung epithelial bioassay: healthy skin, n = 8; class 4, n = 23; class 5, n = 13; and class 6, n = 10. The location of TGF-beta(1) was determined at the light and electron microscopy level with immunocytochemistry and immunogold (IMG) labeling. Multiple comparisons were analyzed with a one-way analysis of variance and the Student-Newman-Keuls post hoc tests. The LC and LT comparisons were analyzed with a two-tailed unpaired t test.

RESULTS

The TGF-beta(1) gene transcripts for control subjects and patients in classes 4, 5, and 6 were 7.02 +/- 7.33, 43.33 +/- 9.0, 16.13 +/- 7.67, and 7.22 +/- 0.56 x 10(-14) mol/microg total RNA, respectively. The transcripts were significantly elevated in class 4 patients only (P </=.05). The amount of active TGF-beta(1) in picograms/gram of tissue from LC and LT biopsy specimens as compared with healthy skin biopsy specimens were as follows: healthy skin, <1. 0 pc/g; class 4: LC, 5061 +/- 1827 pc/g; LT, 317.3 +/- 277 pc/g; class 5: LC, 8327 +/- 3690 pc/g; LT, 193 +/- 164 pc/g; and class 6: LC, 5392 +/- 1800 pc/g; LT, 117 +/- 61 pc/g. Differences between healthy skin and the skin of the patients in classes 4 and 6 were significant (P </=.05 and P </=.01, respectively). Differences between the LC and LT biopsy specimens within each CVI group were also significant: class 4, P </=.003; class 5, P </=.008; and class 6, P </=.02. Immunocytochemistry results of healthy skin showed TGF-beta(1) staining of epidermal basal cells only. CVI dermal biopsy results demonstrated positive staining in epidermal basal cells, fibroblasts, and leukocytes. Many leukocytes had positive staining of intracellular granules, which appeared morphologically similar to mast cells. IMG labeling results demonstrated gold particles in the leukocytes and collagen fibrils of the extracellular matrix.

CONCLUSION

Our study indicated that activated leukocytes traverse perivascular cuffs and release active TGF-beta(1). Positive TGF-beta(1) staining results of dermal fibroblasts were observed and suggest that fibroblasts are the targets of activated interstitial leukocytes. Increased protein production, despite normal levels of gene transcripts in patients in classes 5 and 6, suggests that alternate mechanisms other than gene transcription regulate protein production. A potential mechanism for quick access and release is storage of TGF-beta(1) in the extracellular matrix. IMG labeling to collagen fibrils support this possibility. Furthermore, TGF-beta(1) was exclusively elevated in areas of clinically active disease, indicating a regionalized response to injury. These data suggest that alterations in tissue remodeling occur in patients with CVI and that dermal tissue fibrosis in CVI is regulated by TGF-beta(1).

Sensory impairment: a feature of chronic venous insufficiency

OBJECTIVE

Clinical and microscopic evidence suggests the existence of sensory neuropathy in patients with severe chronic venous insufficiency (CVI). A clinical evaluation was conducted to determine whether a sensory neuropathy was present and, if so, to determine its extent and distribution.

METHODS

The study was performed in a university-affiliated Veterans Affairs Medical Center. Twenty-three limbs were studied in 14 male veterans with mild or moderate CVI. The exclusions included diabetes, previous ipsilateral extremity surgery, or other diseases associated with neuropathy. Sensory thresholds in the limbs with CEAP class 2 disease (n = 11) were compared with the thresholds in the limbs with CEAP class 5 disease (n = 12) at nine different sites on the foot, ankle, calf, thigh, and palm. Thenar and hypothenar thresholds were measured as internal controls. Thresholds were determined by a pressure aesthesiometer consisting of 20 graduated filaments that ranged from 1.65 to 6.65 (log(10)mg)(10) of pressure. A complete, sensory motor assessment of the limb was performed by an experienced neurosurgeon who specialized in peripheral nerve evaluation. The clinical variables assessed were deep tendon reflexes, vibration, proprioception, and light touch. Venous reflux was determined with duplex ultrasound scanning and air plethysmography.

RESULTS

Sensory thresholds at the most common site of venous ulceration-just proximal to the medial malleolus--were significantly (P <.05) different between mild (class 2) and severe (class 5) CVI. Sensory abnormalities coincided with the extent of trophic changes and did not reflect specific dermatomal or cutaneous nerve distributions. In addition to light touch or pinprick, vibration sense and deep tendon reflexes were also significantly worse in those with severe CVI.

CONCLUSION

Sensory neuropathy is a feature of severe CVI, and its distribution is coincident with trophic changes. Because this is often unappreciated by the patient, it probably contributes to the propensity for deterioration from minor trauma.

Patency and limb salvage for polytetrafluoroethylene bypasses with vein interposition cuffs

Polytetrafluoroethelene (PTFE) is often utilized in patients with limb-threatening ischemia requiring infrainguinal revascularization in the absence of autologous saphenous vein. To increase long-term patency of PTFE grafts, vein interposition cuffs have been recommended as adjunctive procedures. The purpose of this study was to assess the efficacy of vein interposition cuffs on the long-term patency and limb salvage of patients requiring prosthetic bypass grafts for limb-threatening ischemia. Prosthetic bypass grafts with vein interposition cuffs (PTFE/VC) were performed on 56 limbs in 55 patients (32 men, 23 women; mean age of 67 years) from October 1993 to January 1998. Grafts were prospectively evaluated every 3 months for the first 12 months and biannually thereafter with duplex ultrasonography. PTFE/VC and PTFE bypasses at the popliteal level appear to have comparable patencies. However, PTFE/VC appear to offer an improved patency and limb salvage for infrapopliteal bypasses in patients with critical limb ischemia. When infrapopliteal revascularization is required in the absence of autologous saphenous vein, we recommend the use of PTFE with vein interposition cuffs.

Endoscopic subfascial perforating vein ligation: its complementary role in the surgical management of chronic venous insufficiency

Endoscopic methods have proven as efficacious as previous open surgical techniques for ligation of calf perforating veins. The reduced incidence of wound complications favors the minimally invasive approach regardless of the technique used. Since isolated disease of the calf perforating veins is rare, most of these procedures are performed in conjunction with superficial venous ablation. These advanced procedures are indicated for patients with skin and subcutaneous manifestations of CVI (CEAP classes 4, 5, and 6). Although the contribution of perforator ligation to the hemodynamic and clinical result is unclear, clinical symptoms and hemodynamics have significantly improved when performed as described.

Hemodialysis access: influence of the human immunodeficiency virus on patency and infection rates

PURPOSE

The complication rate for patients who are dialysis dependent and infected with the human immunodeficiency virus (HIV) and the role of viral indicators (CD4 counts) as predictors of these complications are poorly characterized. To determine the influence of HIV status and viral activity on graft patency and infection rates, we retrospectively reviewed our results.

METHODS

Between June 1993 and March 1997, the charts of 104 patients (HIV+, n = 42; HIV-, n = 62) who required 112 hemodialysis access grafts were reviewed. Of the 112 procedures, 55 (48%) were autologous arteriovenous fistulae (AVF) procedures (HIV+, n = 23; HIV-, n = 32) and 57 (52%) were prosthetic expanded polytetrafluoroethylene grafting procedures (HIV+, n = 27; HIV-, n = 30). Transcutaneous catheter procedures were excluded from the study. The autologous AVF procedures consisted of direct and transposed AVFs. Patency rates were determined by means of life-table analysis. Infection rates and CD4 counts were compared with the chi2 test and the Fisher exact test. Significance was accepted at a P value of.05 or less.

RESULTS

The cumulative 12-month and 24-month patency rates for prosthetic grafts in patients who were HIV+ were 49% and 21%, respectively, versus 77% and 45% for patients who were HIV-. The differences in the prosthetic graft patency rates between these two groups were significant (P </=.05). The cumulative 12-month and 24-month patency rates for autologous AVF procedures did not differ significantly. The AVF procedure patency rates were 72% and 51%, respectively, in patients who were HIV+ versus 54% and 50% for patients who were HIV-. The prosthetic graft infection rate for patients who were HIV+ and HIV- were 30% and 7%, respectively ( P =.04). However, the infection rates in autologous AVF procedures did not differ between the groups (9% vs 0%; P>.05). The mean CD4+ cell counts were 174: CD4+ counts that were less than 200 did not correlate with or predict the development of infection (P >.05).

CONCLUSION

Our data showed that prosthetic graft infection rates were increased and patency rates were decreased in patients who were HIV+ as compared with patients who were HIV- and HIV+ with autologous AVFs. There were no differences in patency rates or infection rates in patients who had undergone autologous access procedures. Long-term graft patency rates were not affected by HIV status, and CD4+ lymphocyte counts were not predictive of infection development. Because the prosthetic graft infection rates exceeded those rates of autologous access procedures, we recommend the vigorous use of autologous AVFs in all patients who are HIV+, regardless of CD4+ count.

Carotid restenosis: operative and endovascular management

PURPOSE

Surgical management of carotid restenosis (CR) after carotid endarterectomy (CEA) has been associated with a higher perioperative complication rate than that of primary CEA. We recently used carotid angioplasty-stenting (CAS) as an alternative to operative management in patients who had undergone CEA within three years, and we retrospectively compared these results with those of operative management of CR and the overall results of CEA.

METHODS

CEA was performed on 1065 adult patients (58% symptomatic, 42% asymptomatic), 62% of whom were men (n = 660) and 38% of whom were women (n = 405), from 1989 to 1997. Before our initiation of a program of CAS, 16 operative procedures (1.9% of CEAs) were performed for CR in 14 adult patients (7 women and 7 men). During the last 20 months, CAS was used in the management of 17 CRs (16 patients; 9 women and 7 men).

RESULTS

The 30-day stroke morbidity-death rate for all CEAs (n = 1065) was 1.4%; 11 strokes (1. 0%) occurred (4 major strokes with disability and 7 strokes with minor or no disability), and 4 deaths (0.4%) occurred (2 deaths caused by myocardial infarction, 1 caused by intracranial hemorrhage, and 1 caused by stroke). Operative management of CR (n = 16) included patch angioplasty in 12 cases (autologous vein patches in 10 cases and synthetic patches in 2 cases), whereas interposition grafting was used in 4 cases (saphenous vein in 3 instances and synthetic [polytetrafluoroethylene] in one case). No strokes or deaths were observed. One recurrent laryngeal nerve palsy occurred (6.2%). Among the 16 patients undergoing 17 CAS procedures, the technical procedures were accomplished in all patients. No strokes or deaths occurred. No recurrent restenoses (50% or greater) have been identified within or adjacent to the CAS procedures.

CONCLUSION

CR caused by myointimal hyperplasia can be managed by operative techniques or CAS with comparable periprocedural complications. Although long-term follow-up will be required to determine the incidence of recurrent restenosis, CAS may become the preferred procedure in these cases. A randomized clinical trial ultimately will be necessary to determine the role of CAS, as compared with that of operative management.

Surgical intervention in venous ulceration

The purpose of this article is to review surgical management for dermal ulceration that results from chronic venous insufficiency. Efficacy is gauged by freedom from recurrent ulceration, an objective clinical monitor. Accurate preoperative diagnosis and postoperative assessment of the venous circulation is enhanced by reliable non-invasive examinations. A recently developed clinical classification unifies reporting criteria and has been widely subscribed. Standard surgical ablation of incompetent saphenous and other superficial veins significantly improves clinical and hemodynamic outcome. Perforator incompetence alone is rarely the cause of ulcerative disease, but adjunctive ligation of communicating veins is considered important to the effective elimination of chronic venous insufficiency. New endoscopic techniques reduce morbidity associated with long incisions from the open subfascial procedure. In a more advanced role, deep venous reconstruction is infrequently performed, but is quite durable. Free-tissue transfer appears to be effective after 2 years of observation. Post-thrombotic chronic venous insufficiency continues to confer a more severe prognosis, which emphasizes the importance of accurate and precise diagnosis. Investigation of patients with ulcerative chronic venous insufficiency should be actively pursued, since individualized surgical management will effectively reduce recurrence of ulceration.

Retinoblastoma protein: a molecular regulator of chronic venous insufficiency

PURPOSE

Chronic venous insufficiency (CVI) and varicose vein (VV) formation is characterized histologically by the transformation of smooth muscle cells (SMC) from a contractile to a secretory phenotype and by intense collagen deposition. The subcellular regulation point for these processes may be the retinoblastoma protein (pRb), a known inhibitor of cellular proliferation and regulator of differentiation. We hypothesize that pRb phosphorylation is associated with VV formation and functions as a possible subcellular regulator.

METHODS

Patients were separated into two groups. Group 1 (n = 6) consisted of vein specimens obtained from patients undergoing coronary artery bypass grafting. Group 2 (n = 6) consisted of patients with symptomatic CVI and duplex confirmed refluxing greater saphenous veins (GSVs) who required GSV stripping. Western blots of GSV protein extracts were performed with anti-human pRb monoclonal antibodies and the degree of nonphosphorylated and phosphorylated pRb was determined. Results were quantified using image analysis of band intensities (computer calibrated intensity units). The ultrastructural appearance of SMCs and the vein wall architecture were qualitatively analyzed with electron microscopy in both groups.

RESULTS

Phosphorylated pRb from varicose GSVs exhibited intensities of 523 +/- 188 units, while phosphorylated pRb from normal GSVs demonstrated intensities of 153 +/- 41 units (P < 0.05). SMCs in varicosed GSVs were surrounded by disorganized collagen deposits and displayed a secretory phenotype with spherical vacuolated cells. SMCs from normal GSVs appeared spindle shaped with a purported contractile phenotype and a well-structured extracellular matrix.

CONCLUSION

Our data demonstrate that VV formation, in patients with CVI, is associated with phosphorylated pRb and the transformation of SMCs from a contractile to a secretory ultrastructural morphology. The data suggest that SMC dedifferentiation is regulated by pRb and the disinhibition of this protein (phosphorylation) may be an significant factor in the development of lower extremity varicosities.

Patency of infrainguinal polytetrafluoroethylene bypass grafts with distal interposition vein cuffs

Polytetrafluoroethylene (PTFE) prosthetic bypasses in the lower extremity have poor patency rates, particularly in limb salvage cases. Patency and limb salvage rates of PTFE bypasses supplemented by distal interposition vein cuffs were assessed in patients requiring revascularization for critical limb ischemia, in the absence of a suitable autologous saphenous vein. Between October 1993 and April 1996, 163 patients underwent 185 infrainguinal bypasses. Forty-three limbs in 42 patients (12 women, 30 men; mean age 67 years) did not have a suitable autologous saphenous vein (24%) and had femoropopliteal (20) and infrapopliteal (23) bypasses performed. Patients were examined prospectively at 3-month intervals during the first year and at 6-month intervals thereafter to determine graft patency and limb salvage. Postoperative anticoagulation with warfarin was used in 26 patients. Indications for operation included limb salvage in 41 extremities (21 rest pain/ulceration or gangrene, 20 rest pain alone), and disabling claudication in two. Patients were followed clinically for 2-30 months (mean 10 months). Cumulative 2-year life-table patencies for all grafts, femoropopliteal and infrapopliteal bypasses were 64%, 75% and 62%, respectively. Previous primary patencies at the authors' institution for PTFE bypasses without vein cuffs were 35%, 46% and 12% for the same categories. Cumulative life-table limb salvage for all PTFE/vein cuff bypasses in the present series was 76% compared with 37% in previous PTFE bypasses without vein cuffs. Adjunctive use of distal interposition vein cuffs improves prosthetic graft patency, while producing satisfactory limb salvage. Postoperative anticoagulation did not influence graft patency. PTFE/vein cuff for lower-extremity revascularization shows good 2-year patency and is an acceptable alternate conduit in patients with critical limb ischemia when autologous saphenous vein is absent.

A strategy for increasing use of autogenous hemodialysis access procedures: impact of preoperative noninvasive evaluation

PURPOSE

We studied the efficacy of preoperative noninvasive assessment of the upper extremity to identify arteries and veins suitable for hemodialysis access to increase our use of autogenous fistulas (AF).

METHODS

From Sep. 1, 1994, to Apr. 1, 1997, 172 patients who required chronic hemodialysis underwent segmental upper extremity Doppler pressures and duplex ultrasound with mapping of arteries and veins. The following criteria were necessary for satisfactory arterial inflow: absence of a pressure gradient between arms, patent palmar arch, and arterial lumen diameter 2.0 mm or more. The criteria necessary for satisfactory venous outflow were venous luminal diameter greater than or equal to 2.5 mm for AF and greater than or equal to 4.0 mm for synthetic bridging grafts (BG) and continuity with distal superficial veins in the arm. Intraoperative and duplex ultrasound measurements were compared. Contemporary experience was compared with the 2-year period (1992 to 1994) before implementation of the protocol.

RESULTS

During the period from Sep. 1, 1994, to Apr. 1, 1997, 108 patients (63%) had AF, 52 (30%) had prosthetic BG, and 12 (7%) had permanent catheters (PC) placed. Early failure was seen in 8.3% of AFs. Primary cumulative patency rates were 83% for AF and 74% for BG at 1 year (p < 0.05), with a mean clinical follow-up of 15.2 months. No postoperative infections were observed with AF, whereas six infections (12%) were observed with BG and two (17%) with PC insertion. During the period from June 1, 1992, to Aug. 31, 1994, 183 procedures were performed with a distribution of 14% AF, 62% BG, and 24% PC. In this earlier period the AF early failure rate was 36%, and the patency rates were 48%, 63%, and 48% for AF, BG, and PC, respectively (mean follow-up, 13.8 months).

CONCLUSION

A protocol of noninvasive assessment increased use of AFs. The cumulative patency rate of AFs was improved, and early failure rates were reduced when compared with the preceding institutional experience. Routine noninvasive assessment is recommended to document adequacy of arterial inflow and delineate venous outflow to maximize opportunities for AF.

Vein transposition in the forearm for autogenous hemodialysis access

PURPOSE

We describe a technique of superficial venous transposition in the forearm used for the formation of an arteriovenous fistula for hemodialysis access. These modifications of the single-incision radiocephalic fistula are designed to increase options for arteriovenous fistulas by using veins and arteries that are suitable for use but are not in immediate proximity.

METHODS

Arteries and veins suitable for a primary arteriovenous fistula were identified and mapped using duplex ultrasound in 89 patients. Separate incisions were used in the majority of cases, and the selected forearm vein was mobilized, angiodilated, and transposed into a subcutaneous tunnel on the volar aspect of the forearm. Before initiation of hemodialysis, duplex ultrasound scanning was performed, and the location that was most suitable for cannulation was identified. Repeat scans were performed at 3-month intervals for analysis of patency.

RESULTS

Superficial venous transpositions were performed using a single incision in 13 instances in which the vein was in immediate proximity to the radial artery (type A). Dorsal-to-volar forearm transposition (type B) was performed in 30 veins with anastomoses to the radial (n = 26), ulnar (n = 2), or brachial (n = 2) arteries. Volar-to-volar forearm transposition (type C) was performed in the remaining 46 veins, with anastomoses to the radial (n = 42), ulnar (n = 2), or brachial arteries (n = 2). Successful hemodialysis was accomplished in 81 of 89 patients (91%). The primary cumulative patency rate was 84% at 1 year and 69% at 2 years. The mean duration of follow-up was 14.3 months.

CONCLUSIONS

The use of superficial venous transposition for the formation of autogenous hemoaccess was associated with ease of cannulation by dialysis personnel, high maturation rates, reduced early failure rates, and enhanced patency rates. We recommended the use of these technical modifications to increase the use of autogenous fistulas in the forearm.

Morphometric assessment of the dermal microcirculation in patients with chronic venous insufficiency

PURPOSE

Ultrastructural assessments of the dermal microcirculation in patients with chronic venous insufficiency have been limited to qualitative morphologic descriptions of venous ulcer edges or venous stasis dermatitis. The purpose of this investigation was to quantify differences in endothelial cell structure and local cell type with emphasis on leukocytes and their relationship to arterioles, capillaries, and postcapillary venules (PCVs).

METHODS

Two 4.0 mm punch biopsies were obtained from areas of dermal stasis skin changes in the gaiter region of the leg, as well as from noninvolved areas of skin in the ipsilateral thigh, from 35 patients: CEAP class 4 (11 patients), class 5 (9 patients), class 6 (10 patients), and five normal skin biopsies from patients without chronic venous insufficiency. Electron microscopy was performed on sections at 6700x and 23,800x magnification. At 6700x endothelial cell thickness was determined, and the number of fibroblasts, leukocytes, and mast cells were recorded relative to their proximity to arterioles, capillaries, and PCVs. Similarly, at 23,800x endothelial cell vesicle density, interendothelial junctional widths, and basal lamina thickness (cuff width) were measured. Preliminary evaluation for the presence of transforming growth factor-beta 1 (TGF-beta 1) was performed on three patients using reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Quantitative measurements demonstrated increased mast cell content for class 4 and 5 patients around arterioles and PCVs and increased macrophage numbers for class 6 patients around PCVs (p < 0.05). Fibroblasts were the most common cells observed; however, no differences were demonstrated between groups. No differences were observed in interendothelial junctional widths or vesicle densities in arterioles, capillaries, or PCVs. Basal lamina thickness was increased only at the capillary level (p < 0.05). The results of RT-PCR for TGF-beta 1 messenger RNA were positive in the three patients studied.

CONCLUSIONS

Our data suggest that (1) mast cells play a role in the pathogenesis of chronic venous insufficiency; (2) the effects of mast cells, macrophages, or both may be mediated in part by TGF-beta 1; and (3) capillary cuff formation is not associated with widened interendothelial gap junctions, but may be a result of enhanced vesicular transport rate or conformational changes in the interendothelial glycocalyx.

Carotid arterial trauma: assessment with the Glasgow Coma Scale (GCS) as a guide to surgical management

Management of carotid arterial injuries associated with focal neurological deficit or altered state of consciousness (SCON) remains unresolved. Experience with these injuries in one particular hospital was reviewed and the Glasgow Coma Scale (GCS) utilized to assist with clinical stratification of these patients. A literature review was also conducted to better define indications for repair or ligation of carotid injuries. From 1978 to 1990, 34 patients with carotid arterial injuries were reviewed with reference to the GCS, focal deficit, hypotension, anatomic site and mechanism of injury. The literature from 1952 to 1993 was surveyed for carotid artery injuries (1316 patients). Outcome of treatment with or without repair was compared with pre-operative neurologic status. Thirty-four patients with injuries of the common (24) or internal (10) carotid arteries were managed with repair (68%), ligation (24%) or observation (9%). The SCON was normal in 18 patients; 16 patients (88%) underwent repair and all remained normal. All patients with GCS 9-14 regained a normal SCON after surgical repair, while 10 patients with GCS < 8 had repair (5), ligation (3), and non-operative management (2); five returned to normal, four died and one remained comatose. However, outcomes correlated poorly with management. Of 1316 patients cited in the surgical literature, patients with no deficit and patients with pre-operative deficits did significantly better after repair as compared with ligation (P<0.001). In comatose patients, management did not affect outcome. It is concluded that carotid arterial injuries should be repaired in patients with normal neurologic evaluation, focal pre-operative neurologic deficits and in patients with GCS > 9. Comatose patients with GCS < 8 do poorly regardless of management. The GCS provides an objective for stratification of patients with altered SCON who benefit from repair of carotid arterial injuries.

Outcome of complex venous reconstructions in patients with trauma

PURPOSE

The role of complex venous reconstructions (CVRs) in patients with major trauma remains a controversial topic. This study evaluates the patency and clinical outcome of CVRs in a major urban trauma center.

METHODS

Between 1979 and 1994 the records of 92 patients with 100 injuries to the iliac, femoral, and popliteal venous system were reviewed. The incidence of edema, pulmonary embolism, and limb loss was documented in 75 men and 17 women (mean age of 27 years, range 14 to 59 years). The 30-day patencies were assessed in all patients with either impedance plethysmography (n = 16), venography (n = 40), or duplex scan (n = 36). Long-term patencies were assessed in 14 patients monitored for 0.5 to 9 years (mean 3.2 years).

RESULTS

Mechanisms of injury consisted of 58 gunshot wounds, 23 stab wounds, 6 shotgun wounds, and 5 blunt injuries. There were 112 associated injuries, 41 of which were concomitant arterial injuries. Forty-five of the 100 venous injuries were repaired with CVRs and included 6 (13%) spiral vein grafts, 8 (18%) panel vein grafts, 8 (18%) reversed saphenous vein interposition grafts, 8 (18%) end-to-end repairs, and 15 (33%) vein patch repairs. Thirty-day patency rates for these repairs were 50%, 50%, 75%, 88%, and 87%, respectively, and an overall patency rate of 73% was observed. The remaining 55 injuries were treated with ligation (n = 27) or lateral venorrhaphy (n = 28). The cumulative 30-day patency rate for all venous repairs was 81% (59 of 73). Fourteen patients, nine of whom had CVRs, were available for long-term follow-up. In this group CVRs demonstrated a 100% patency. One patient with a spiral vein graft repair of the common femoral vein had severe reflux causing intermittent edema and mild lipodermatosclerosis. No pulmonary emboli, limb loss, or deaths were identified in patients undergoing CVRs.

CONCLUSION

Patients with CVRs had a 30-day patency rate of 73%. Of this group panel and spiral vein grafts were less successful, exhibiting only a 50% 30-day patency rate, whereas end-to-end and vein patch repairs were successful in 88% and 87% of cases, respectively. Our overall evaluation suggests that use of CVRs results in successful venous repair; however, the postoperative patency of interposition panel and spiral grafts suggests selective use of these techniques.

A program of operative angioplasty: endovascular intervention and the vascular surgeon

PURPOSE

Vascular surgeons are ideally suited to select and perform endovascular interventions either as primary therapy or as an adjunct to bypass surgery. Attaining proficiency in endovascular techniques is an important goal in the training of vascular surgeons. We report our initial experience with a program of endovascular intervention performed in the operating room by vascular surgeons.

METHODS

During the previous three years, we performed 109 angioplasty procedures, 60 aortoiliac (55%), 32 femoropopliteal (29%), and 17 popliteal/tibial (16%), using guidewires and angioplasty balloons directed by intraoperative digital subtraction C-arm arteriography with road-mapping capabilities. Indications for angioplasty included disabling claudication in 59 patients (54%), rest pain in 18 (17%), and tissue loss in 32 (29%). Angioplasty was accompanied by stent placement in 39 of 60 aortoiliac procedures (65%) and in two of 32 femoral procedures (6%). In 16 cases (15%), the endovascular procedure was performed in conjunction with a bypass procedure. In selected cases (15, 14%), duplex scanning was the sole diagnostic method used before surgery to identify the lesion, eliminating the need for preoperative arteriographic scans. Segmental pressure measurements, duplex ultrasound scans, and treadmill exercise testing as indicated were performed before and after surgery. The efficacy of the endovascular intervention was assessed at 3-month intervals during the first year and at 6-month intervals thereafter.

RESULTS

A successful results was defined using criteria recommended by the Ad Hoc Subcommittee on Reporting Standards for Endovascular Procedures from the Society for Vascular Surgery/International Society for Cardiovascular Surgery. This included the combination of symptomatic improvement, obtaining an anatomically successful result with < 30% residual lumen stenosis, and elimination of the translesion gradient with an improvement in high thigh-brachial index or ankle-brachial index greater than 0.15. Initial success was achieved in 55 of 60 aortoiliac (92%), 28 of 32 femoropopliteal (88%), and 16 of 17 popliteal/tibial (94%) angioplasty procedures. Clinical follow-up has been achieved in all cases, with continued clinical success rates of 80%, 75%, and 82% for aortoiliac, femoropopliteal, and popliteal/tibial angioplasty procedures, respectively, with a mean follow-up of 15.7 months.

CONCLUSION

These results confirm the value of a program in which C-arm technology was used by vascular surgeons in the performance of angioplasty and stenting procedures in the operating room. This experience in therapeutic endovascular intervention will facilitate the credentialing process for future vascular surgeons.

Hemodynamic and clinical improvement after superficial vein ablation in primary combined venous insufficiency with ulceration

PURPOSE

This study was undertaken to determine the degree of clinical and hemodynamic improvement after surgical ablation of incompetent superficial and perforator veins in limbs with combined deep and superficial venous incompetence manifested by chronic dermal ulceration.

METHODS

Eleven limbs in 10 patients with class 5 or 6 venous insufficiency (ulceration) were assessed by CEAP (clinical, etiologic, anatomic, pathophysiologic) clinical scores, air plethysmography, color duplex ultrasonography, and phlebography (both ascending and descending). Surgical ablation of superficial and perforating veins was performed, followed by repeat clinical, air plethysmographic, and color duplex ultrasonographic examinations.

RESULTS

All 11 limbs had combined deep and superficial vein reflux on the preoperative color duplex ultrasound scan. Clinical symptom scores decreased from 10 to 1.4 after operation. Postoperative air plethysmography demonstrated significant reduction in reflux as measured by the mean venous filling index, which decreased from 12 +/- 5 ml/sec to 2.7 +/- 1 ml/sec after surgery. Calf pump function was also significantly improved, with a mean ejection fraction that increased from 43% +/- 11 to 59% +/- 13 and mean residual volume fraction that decreased from 56% +/- 15 to 33% +/- 16. Each of these measures was significantly different from the preoperative value (p < 0.05). Similar improvement characterized subgroups of limbs with three or more incompetent deep segments (n = 6) or popliteal segment incompetence (n = 6).

CONCLUSIONS

Superficial and perforating vein incompetence accounts for a substantial and correctable component of venous insufficiency in limbs with combined deep and superficial vein reflux and venous ulceration. These data indicate that surgical correction of this component significantly improves clinical symptoms and venous hemodynamics. Superficial and perforator ablation is an appropriate initial step in the management of combined deep and superficial venous incompetence.

Transcutaneous oxygen (TcPO2) estimates probability of healing in the ischemic extremity

The severity of arterial ischemia is a major variable affecting healing of extremity wounds. By relating risk of failure to severity of ischemia, the probability of wound healing may be stratified along with assessment of general medical risks. Transcutaneous oxygen tension (TcPO2) arterial segmental pressure (ASP), and arterial segmental indices (ASI) were obtained in 204 ischemic lower extremity sites; 63% of the sites were in patients with diabetes mellitus (DM), 11% in patients with chronic renal failure (CRF), and 37% in patients with neither DM nor CRF (ND). Wounds included 126 amputations and 78 gangrenous ulcerations of the foot or toes. Healing (n = 112) was defined as complete wound closure, without regard to the time required. Failure (n = 92) was defined by the requirement for either arterial reconstruction (n = 45) or proximal amputation (n = 47). Stepwise multiple regression analysis was used to assess the relative contribution of each measurement and to predict the probability of healing; TcP02 was superior to ASP and ASI in all categories. TcP02 was the only test meeting the P < 0.05 entry criteria modeled by the regression. An accuracy of 83% was achieved. However, when each test was evaluated by univariate analysis, ASP and ASI did meet the criteria for the ND group. However, the accuracy was 68 and 72%, respectively. Predictive accuracy of TcP02 was unaffected by DM or CRF. ASP and ASI were satisfactory in the ND group, although of slightly reduced accuracy. ASP and ASI were misleading and inaccurate in DM and CRF. Thus, of the noninvasive tests, TcP02 alone is sufficient for objective risk stratification of arterial ischemia in the lower extremity.

Limited range of motion is a significant factor in venous ulceration

PURPOSE

Calf muscle pump dysfunction is a recognized factor in chronic venous insufficiency (CVI). We investigated the hypothesis that limbs with CVI have a reduced ankle range of motion (ROM) that may be responsible for the poor calf pump function associated with venous ulceration.

METHODS

Ankle ROM and calf pump function were assessed in 32 limbs of 26 adult men. Limbs were selected on the basis of clinical presentation: normal (n = 6 limbs), class 1 or 2 CVI with no history of ulceration (n = 9 limbs), class 3 CVI with healed ulceration (n = 9 limbs), and class 3 CVI with active ulceration (n = 8 limbs). ROM was determined by goniometry during maximal plantar flexion and dorsiflexion of the ankle. Calf pump function was determined by air plethysmographic measurement of ejection fraction (EF) and residual volume fraction (RVF).

RESULTS

Ankle ROM was significantly (p < 0.05) reduced in each CVI group compared with age-matched control subjects, because of decreases in both plantar flexion and dorsiflexion. Calf pump function was significantly impaired (decreased EF and increased RVF) in ulcerated limbs. ROM was significantly correlated to EF and RVF. Impairment of ROM and calf pump function was associated with deterioration in the clinical classification of venous disease.

CONCLUSIONS

Limbs with CVI have a limited ankle ROM that decreases with increasing severity of clinical symptoms. This decreased ROM is associated with, and may contribute to, poor calf pump function.

Accuracy of disincorporation for identification of vascular graft infection

OBJECTIVE

The presence or absence of prosthetic graft incorporation with surrounding tissue was assessed relative to bacterial culture results, using enhanced microbiologic culture techniques.

DESIGN

Criterion standard.

SETTING

University and Veterans Affairs hospital.

PATIENTS

Prosthetic samples were removed from 113 aortofemoral, extra-anatomic, infrainguinal, and hemoaccess sites at the time of vascular reoperative surgery. Harvested grafts were sonicated. Density of organisms was determined by quantitative culture.

MAIN OUTCOME MEASURES

The culture result was predicted from the status of prosthetic incorporation or disincorporation as determined at surgery. For purposes of this study, any bacterial growth represented graft infection.

RESULTS

Cultures positive for bacteria were obtained from 31 sites; cultures with no growth, from 82. Thirty-one of the 113 sites were disincorporated, of which 23 yielded cultures positive for bacteria, and eight, no growth. The remaining 82 sites were well incorporated, of which 74 yielded cultures negative for bacteria, and eight, bacterial growth. Sixteen (14%) incorrect predictions were noted. The concurrence of disincorporation and a culture positive for bacteria relative to all culture-positive grafts (sensitivity) was 74%. The concurrence of incorporation and cultures negative for bacteria relative to all culture-negative grafts (specificity) was 90% in prostheses implanted for longer than 2 weeks; in prostheses implanted for longer than 12 weeks, specificity was 97%.

CONCLUSIONS

The surgical finding of incorporation or disincorporation accurately predicted the culture result in 89% of the sites. Disincorporation correlated with presence of bacteria in 71%; incorporation reliably excluded the presence of bacteria in 97%.

The significance of calf muscle pump function in venous ulceration

PURPOSE

Patients with clinically evident chronic venous insufficiency were evaluated to relate the degree of insufficiency and calf muscle pump dysfunction to venous ulceration.

METHODS

Sixty-nine limbs in 55 patients with chronic venous insufficiency by Society for Vascular Surgery/International Society for Cardiovascular Surgery Classification were compared in three groups: classes 1 and 2 with no history of ulceration (19 limbs); class 3 with healed ulceration (20 limbs); and class 3 with active ulcers (30 limbs). Air plethysmography measurements of outflow fraction, venous volume, venous filling time, venous filling index, ejection fraction, ejection volume, residual volume fraction, and residual volume were made. In 62 of the 69 limbs, color-flow duplex ultrasonography was used to determine the pattern of reflux.

RESULTS

The outflow fraction was normal in 84%, 75%, and 77% of nonulcerated, healed, and ulcerated limbs. The venous filling index was abnormal in most limbs (nonulcerated 95%, healed 90%, ulcerated 98%) but not significantly different among groups. Differences in calf muscle pump function were significant. Ulcerated limbs had significantly poorer ejection fractions (p = 0.0002) and greater residual volume fractions (p = 0.0006) than nonulcerated or healed limbs. By ultrasonography, deep and superficial vein incompetence was present in most limbs and was not statistically different among groups. Although venous insufficiency was not measurably different among groups, limbs with active venous ulcers had significantly poorer calf muscle pump function than those with healed ulcers or with no history of ulceration.

CONCLUSION

Venous insufficiency is necessary but not sufficient to cause ulceration, and a deficiency of the calf muscle pump is significant to the severity of venous ulceration.

Refinements in the ultrasonic detection of popliteal vein reflux

Color-flow and duplex ultrasonography were used to determine the optimal method for documenting venous valvular reflux. Popliteal veins were examined in 10 normal limbs and 11 limbs with clinical evidence of chronic venous insufficiency (CVI). Peak reflux velocity (spectral) and duration of reflux (spectral and color) were measured with the patient in supine and standing positions, with manual and pneumatic compression applied sequentially to thigh and calf. Manual and pneumatic compression produced equivalent reflux velocity and duration. In normal limbs peak reflux velocity was always less than 22 cm/sec, with a mean reverse flow duration of 0.3 sec +/- 0.03 (SEM). In limbs with CVI, reflux velocity varied widely among protocols. Reflux duration and velocity were greater in the supine position than in the standing position for both normal limbs and limbs with CVI (p < 0.04). Duration was significantly increased for thigh versus calf compression in normal limbs (p < 0.001) but decreased in limbs with CVI (p < 0.003). Methods that used thigh compression or supine position were less capable of discriminating normal limbs from limbs with CVI. Standing calf compression provided the greatest rates of sensitivity (91%), specificity (100%), and accuracy (95%). Compared with spectral Doppler scanning, color-flow ultrasonography produced a consistently shorter reflux duration (p < 0.001). In limbs with CVI with a mean spectral duration of 2.5 sec +/- 0.2 (SEM), mean color Doppler duration was 0.7 sec shorter. Our results demonstrate that popliteal vein incompetence is identified optimally by reflux duration after standing calf compression; adequate manual compression is sufficient to identify reflux; color-flow Doppler ultrasonography may underestimate reflux duration.

Iatrogenic placement of a Tenckhoff catheter in the bladder of a diabetic patient after penectomy

The placement of permanent peritoneal catheters for dialysis of patients with renal failure is safe and has been popular since its modification by Tenckhoff. The majority of complications associated with these catheters are infectious in nature, manifesting as peritonitis or insertion site skin infections. Occasionally, serious complications may occur. We report the iatrogenic placement of a Tenckhoff catheter in the bladder of a penectomized patient. Consideration to this surgically altered lower genitourinary tract may have avoided this rare complication as well as aided in the postoperative management of this patient.

Arterial intimal flaps: a comparison of primary repair, aspirin, and endovascular excision in an experimental model

The optimal management for traumatic arterial intimal injuries is unresolved. Three therapeutic options were compared in an experimental model employing a standard intimal flap created in 51 canine superficial femoral arteries. Group 1 (14 arteries) underwent resection with end-to-end repair. Group 2 (19 arteries) received acetylsalicylic acid (ASA) and observation only. Group 3 (21 arteries) underwent endovascular excision of the flap with angioscopic guidance. Control intimal flaps (18 arteries) were created and observed without further intervention. Patency in group 1 (primary repair) and group 2 (ASA) was 100%; the patency in both was significantly (p < 0.05) greater than in the controls, which was 67%. Patency in group 3 (endovascular excision) was 79%. Residual luminal defects were observed in only 8% of the arteries repaired primarily, but in 76% of the aspirin-treated arteries. Residual luminal defects following endovascular excision were present in 53% of the arteries remaining patent. Although resection and primary repair (group 1) provided better results than observation alone (control), addition of ASA (group 2) also sustained patency. However, a high incidence of residual intimal defects occurred, the natural history of which is unknown. While endovascular excision (group 3) may become a feasible alternative, current technology provided inferior patency with frequent residual intimal defects. These results suggest that observation alone supplemented with antiplatelet medication (ASA) may be adequate treatment, but longer follow-up is necessary for confirmation.

Infrapopliteal arterial injury: prompt revascularization affords optimal limb salvage

Sixty-nine limbs with infrapopliteal arterial injuries were evaluated in 68 patients. Thirty-five (50%) cases were complicated by acute limb-threatening ischemia. Management consisted of revascularization (26 limbs), ligation (15 limbs), fasciotomy only (2 limbs), observation (18 limbs), and primary amputation (8 limbs). Penetrating injuries (n = 35) had a 33% incidence of ischemia and a reduced frequency of associated injury. One delayed amputation (3%) was required. In contrast, blunt injuries (n = 34) had a 68% incidence of ischemia and a greater frequency of associated injury. There were 20 amputations in the blunt group, including eight primary amputations performed in limbs with profound ischemia, complex open fractures, severe soft-tissue damage, and neural injury. Observation or ligation of single arterial injuries resulted in no early amputations. Associated local injuries in both groups included fracture or ligamentous disruption (64%), severe soft-tissue damage (32%), and nerve dysfunction (36%). In both groups, 15 of 35 ischemic limbs were salvaged by prompt revascularization (11 penetrating and four blunt injuries). Aggressive revascularization with autogenous repair or bypass is recommended for management of penetrating trauma. Though a good outcome will be achieved in some patients with combined blunt trauma and infrapopliteal arterial injury, the probability of delayed amputation and prolonged disability must be consciously integrated into the decision to pursue limb salvage. The prognosis for blunt injury complicated by arterial ischemia is poor; thus the severity of associated local and remote injuries will affect the results of revascularization program.

Comparison of heated-probe laser Doppler and transcutaneous oxygen measurements for predicting outcome of ischemic wounds

Transcutaneous oxygen (TcPO2) measurement has proven to be an accurate means of predicting healing of ischemic wounds. This study compares the ability of TcPO2 and laser Doppler, modified by the addition of a heated probe (LDHP), to assess wound outcome. TcPO2 and LDHP measurements were made at the same site for 80 wounds, which consisted of 51 amputations (25 above knee, 6 below knee, 20 forefoot) and 29 ulcerations. Healing was defined as complete wound closure. Failure to heal was defined by the necessity for proximal amputation in 22 wounds (6 amputations, 16 ulcers). Outcome criteria were chosen to maximize accuracy and either positive or negative predictive values. Criteria with the greatest accuracy and positive predictive value for wound healing were > or = 11 mmHg for TcPO2 and > or = 50 mv for LDHP range. Criteria with the most appropriate accuracy and negative predictive value for wound failure were < 5 mmHg for TcPO2 and < 35 mv LDHP range. All wounds whose LDHP range was < 35 mv failed to heal, whereas some wounds with a TcPO2 of 0-1 mmHg healed successfully. An absolute prediction of wound healing (100% specificity and negative predictive value) was offered when either LDHP range was > or = 125 mv or TcPO2 was > or = 33 mmHg, although accuracy of either measurement at this criteria was unacceptable for more general application. We conclude that TcPO2 or LDHP will assess wound outcome with similar overall accuracy, although each test may be better for predicting a specific outcome.

Optimal method for culturing vascular prosthetic grafts

Vascular prosthetic infection may be underrecognized when identified by standard culture techniques. Improved microbiologic methodology may enhance detection of bacteria in prosthetic graft specimens, and thus may alter clinical decisions. Quantitative culture techniques were employed to compare three methods of enhancing bacterial recovery from Dacron graft cylinders seeded with commonly encountered bacterial pathogens. Methods included: (1) ultrasonic bath treatment, (2) direct ultrasonic disruption, and (3) agitation on a Vortex mixer. Ultrasonic bath treatment released bacteria with colony counts that were consistently greater by 1 log than direct ultrasonic disruption and Vortex agitation. Direct ultrasonic disruption at high energy levels selectively killed gram-negative bacteria by as much as a 4 log decrease in viable organisms. Agitation (Vortex mixing) of the specimen produced the lowest counts among the three methods tested. These data would indicate that a 5-min ultrasonic bath treatment was the optimal method of preparation of vascular prostheses for bacterial culture.

Hemoaccess site infection

Infectious complications involving a hemoaccess graft or fistula are a significant cause of morbidity in patients on chronic hemodialysis. A review of 274 consecutive hemoaccess procedures identified 28 infections (an incidence of 10 per cent). Infections occurred in 27 polytetrafluoroethylene (PTFE) grafts. The predominant organism was Staphylococcus aureus. Partial excision resolved 14 of the 27 graft infections. The remaining 13 required complete removal. Surgical management required six arterial ligations and seven autogenous reconstructions. No limb ischemia or mortality was directly attributable to these procedures. One infection occurred in 48 autogenous fistulas (an incidence of 2 per cent). Although partial removal of an infected prosthesis was often sufficient, brachial artery ligation was well tolerated when required to control anastomotic infection.

The arterial wall response to intimal injury in an experimental model

Repair of occult arterial injuries is advocated to prevent thrombosis, arteriovenous fistula, and pseudoaneurysm formation. However, recent clinical series describe the healing of arterial intimal injuries and recommend nonoperative therapy. To investigate the arterial wall response to intimal injury, we created intimal flaps in 46 canine femoral arteries. The intimal flaps were imaged by arteriography, angioscopy, and intravascular ultrasound acutely, and at one and three weeks and five months post-injury. Lumen area was measured using caliper techniques (arteriography) and computerized video planimetry (angioscopy, intravascular ultrasound). Intimal and medial thickness were measured by intravascular ultrasound prior to harvest for histologic evaluation by light microscopy. Analysis of 32 patent arteries was performed after exclusion of 14 thrombosed arteries. Residual lumen area (mm2) correlated closely among the imaging modalities at one week (8.7 +/- 1.1, 7.3 +/- 2.0, 6.9 +/- 1.8), three weeks (4.2 +/- 0.9, 2.9 +/- 1.0, 2.7 +/- 0.8), and five months (5.3 +/- 0.9, 5.0 +/- 0.5, 5.0 +/- 0.9). Maximal intimal and medial thickness occurred three weeks post-injury, coincident with the maximal reduction in lumen area. Although intimal injuries can cause acute and delayed arterial thromboses, observation may be appropriate in selected cases. The evaluation of those patients chosen for nonoperative therapy should extend beyond three weeks, as this is the time of maximal arterial wall response with a continued potential for adverse clinical events.

Bactericidal effects of antibiotics on slowly growing and nongrowing bacteria

Antimicrobial agents are most often tested against bacteria in the log phase of multiplication to produce the maximum bactericidal effect. In an infection, bacteria may multiply less optimally. We examined the effects of several classes of antimicrobial agents to determine their actions on gram-positive and gram-negative bacteria during nongrowing and slowly growing phases. Only ciprofloxacin and ofloxacin exhibited bactericidal activity against nongrowing gram-negative bacteria, and no antibiotics were bactericidal (3-order-of-magnitude killing) against Staphylococcus aureus. For the very slowly growing gram-negative bacteria studied, gentamicin (an aminoglycoside), imipenem (a carbapenem), meropenem (a carbapenem), ciprofloxacin (a fluoroquinolone), and ofloxacin (a fluoroquinolone) exhibited up to 5.7 orders of magnitude more killing than piperacillin or cefotaxime. This is in contrast to optimally growing bacteria, in which a wide variety of antibiotic classes produced 99.9% killing. For the gram-positive and gram-negative bacteria we examined, antibiotic killing was greatly dependent on the growth rate. The clinical implications of slow killing by chemotherapeutic agents for established bacterial infections and infections involving foreign bodies are unknown.

A prospective evaluation of arterial intimal injuries in an experimental model

The management of arterial intimal defects remains controversial because of uncertainty concerning their natural history. We developed an experimental canine model to prospectively evaluate posterior wall intimal flaps in the superficial femoral artery. Arterial intimal flaps were constructed in 20 anesthetized dogs (40 arteries) and evaluated by arteriography, and angioscopy, and intravascular ultrasound. Postoperative patency rates at 1 (n = 20) and 3 weeks (n = 20) were compared with a control group of ten animals (n = 20, arteriotomy without intimal flap). Acute thromboses occurred in five experimental arteries with thromboses of eight additional experimental arteries at followup. Control patency was 100%, while experimental group patencies were 75% (p less than 0.05) at 1 week and 60% (p less than 0.009) at 3 weeks. All thrombosed arteries had intimal flaps with greater than 75% luminal stenosis. We conclude that intimal injuries cause arterial thromboses acutely and during subsequent followup. Intimal flaps with stenosis greater than 75% as determined arteriographically are at greatest risk for thrombosis. Angioscopy and intravascular ultrasound characterize arterial intimal defects and may delineate injuries requiring surgical or endovascular repair.

Carotid endarterectomy for asymptomatic carotid stenosis: a ten-year experience with 120 procedures in a fellowship training program

Performance of carotid endarterectomy for asymptomatic carotid stenosis has been restricted during recent years because of concern of reported complications in as high as 10-15% of patients, as well as limited long-term data on stroke protection. During the last 10 years, we have studied immediate and long-term results of carotid endarterectomy for asymptomatic disease in 120 patients. Operations were performed by a clinical vascular fellow with a staff surgeon in attendance in 113 (94%) cases with the remainder performed by the staff surgeon. Patients' mean age was 66 years; 82% were men. Risk factors included hypertension (56%), smoking (52%), coronary artery disease (32%), diabetes (24%), and hypercholesterolemia (6%). Arteriographic severity of stenoses was 80-99% in 74%, 60-79% in 22%, and 40-59% in 4% of cases. Postoperative complications included two transient neurological events (1.7%). No permanent strokes or deaths occurred. Using the life table method, cumulative stroke rate was 4.5% for ipsilateral events and 7.3% for contralateral events, confirming the high degree of stroke protection afforded by carotid endarterectomy in this population. Since these results were accomplished in a fellowship training program, we regard adequacy of this experience as the most influential factor in accomplishing this record. Surgeons who are unable to achieve comparable results should consider abandonment of the procedure or an extended period of additional training.

Popliteal artery agenesis: a new anatomic variant

Agenesis of the popliteal artery has not been described as a vascular anomaly in the lower extremity. This case report describes congenital absence of the popliteal artery discovered during operative exploration after a traumatic injury to the lower extremity. The preoperative arteriogram suggested acute occlusion of the popliteal artery. Intraoperative exploration and arteriography were consistent with agenesis of the popliteal arterial segment, and postmortem examination confirmed these arteriographic and intraoperative observations. Embryologically, failure of the middle portion of the sciatic artery to persist would account for this anomaly. A review of series reporting congenital anomalies of the lower extremity vasculature failed to discover previous mention of this particular abnormality. Agenesis of the popliteal artery should be included among those vascular anomalies that may affect management of lower extremity vascular disease.

Reduced dependency on arteriography for penetrating extremity trauma: influence of wound location and noninvasive vascular studies

Indications for arteriography in penetrating extremity trauma remain controversial. We reviewed our clinical experience in 454 patients (514 extremities) with penetrating trauma admitted during a prior 3 1/2-year period. Injuries were caused by stab wounds in 60 (11.7%) extremities and by gunshot wounds in 454 (88.3%) extremities. Thirty-three of the 60 stab wounds (55%) required urgent exploration, and 27 underwent arteriography. No arteriograms were positive for unsuspected arterial injury in this group. Forty-two of 454 gunshot wounds (9.3%) underwent mandatory exploration; arteriograms were performed on 412 extremities. Forty-four arteriograms (10.7%) demonstrated evidence of unsuspected arterial injuries. During the last year, randomly selected extremities (n = 23) have been studied with B-mode ultrasonography and segmental Doppler pressure measurements. Using the subsequent arteriography as the "gold" standard, sensitivity was 83% and specificity was 100%. Gunshot wounds were categorized according to location and positive arteriograms. Injuries to the lateral thigh and arm resulted in no positive arteriograms, while positive studies were observed in 11% of medial and posterior arm, 14% of antecubital fossa, 25% of forearm, 7.5% of medial and posterior thigh, 8% of popliteal fossa, and 26% of calf injuries. We recommend arteriography for gunshot injuries to identified high-risk areas, while clinical evaluation alone is accurate in all stab wounds to the extremities and gunshot wounds to the lateral thigh and outer arm. Preliminary data suggest expanded use of B-mode ultrasonography may further reduce our dependency on arteriography in these cases.

Penetrating extremity trauma: identification of patients at high-risk requiring arteriography

Indications for arteriography in patients with penetrating trauma to the extremities remain controversial. Some clinicians have recommended universal use of arteriography, whereas others prefer to rely on physical findings alone. To better define our indications for contrast studies, we reviewed clinical data on 306 patients (349 extremities) with penetrating trauma who were admitted during a prior 2-year period (1985 to 1987). Injuries were caused by stab wounds in 50 (14.3%) extremities and by gunshot wounds in 299 (85.7%) extremities. Twenty-seven of the 50 stab wounds (54%) required urgent exploration based on physical findings, whereas 23 underwent arteriography. None of these studies showed unsuspected arterial injury. Twenty-nine of 299 gunshot wounds (9.7%) underwent mandatory exploration, and arteriograms were performed on 270 extremities; findings in 30 studies (11.1%) were positive for unsuspected arterial injuries. Gunshot wounds were categorized according to location and number of arteriograms with positive results. Arteriograms of lateral thigh and upper arm injuries resulted in no positive outcomes. Positive study results were recorded in 22.9% of calf injuries, 20% of forearm and antecubital injuries, 9.5% of popliteal fossa injuries, 9.0% of medial and posterior thigh injuries, and 8.3% of medial and posterior upper arm injuries. We recommend arteriography for penetrating injuries to these high-risk areas. However, clinical evaluation alone is accurate for identification of arterial trauma with lateral thigh or upper arm wounds and stab wounds to the extremities.

Acute ischemia-reperfusion injury in the canine hindlimb

A canine arterial ligation preparation was used to produce whole limb ischemia-reperfusion injury. Alterations in the distribution of arterial blood flow as well as the morphology of skeletal muscle ischemia-reperfusion have not been investigated completely in this setting. Five anesthetized adult mongrel dogs underwent multiple infrarenal aortic branch ligations; one randomly selected hindlimb was subjected to six hours of ischemia and two hours of reperfusion, while the opposite limb served as control. Distribution of arterial blood flow was analyzed by injection of radiolabeled microspheres. Electromagnetically measured femoral arterial blood flow was 92 +/- 10 ml/min during control, and increased significantly (p less than 0.05) to 254 +/- 94 ml/min during reperfusion. Flow distribution to skin, muscle, and bone was 9 +/- 2%, 68 +/- 7%, and 8 +/- 1% during control, and 7 +/- 3%, 65 +/- 8%, and 9 +/- 4% after reperfusion, which did not represent significant changes. Arteriovenous shunting was 11 +/- 4% during control, and was 13 +/- 5% during reperfusion, which was not significantly different. Subcellular injury in the ischemic and reperfused hindlimb was demonstrated by light and electron microscopy. These findings further characterize whole limb ischemia-reperfusion injury in the canine hindlimb.

Dexamethasone attenuates microvascular ischemia-reperfusion injury in the rat cremaster muscle

We examined the effect of dexamethasone (DXM) pretreatment on microvascular transport of macromolecules in ischemia-reperfusion injury. The rat cremaster muscle was splayed, placed in a Lucite intravital chamber, and suffused with bicarbonate buffer. The clearance of fluorescein isothiocyanate-dextran 150 (FITC-Dx 150) was measured as an index of microvascular transport. After determination of baseline data, the muscle was made ischemic for 2 hr by clamping its vascular pedicle, and subsequently reperfused for 2 hr. Ischemia-reperfusion produced a marked increase in clearance of FITC-Dx 150. After an initial peak of 13 times baseline value clearance fell to approximately 4 times baseline level 30 min into the reperfusion period. Clearance increased slowly throughout the remainder of the experiment, reaching 6 times baseline after 2 hr of reperfusion. The treated animals received DXM 3 hr prior to and immediately preceding the pedicle clamping. DXM reduced macromolecular clearance significantly after the first 30 min of reperfusion, and prevented the increase in clearance over time. After an initial peak, clearance values fell to near twice baseline in DXM-treated animals, and remained at this level for the 2 hr of reperfusion. Our data demonstrate that DXM attenuates the alternations in microvascular macromolecular transport produced by ischemia-reperfusion injury.

Lateral approach to the popliteal artery

A lateral approach to the popliteal artery is described. The anatomic limits of the exposure, appropriate technical maneuvers to maximize this exposure, and alternative procedures are discussed. Groin or thigh infections in patients requiring urgent revascularization are the most common indications. However, some traumatic injuries and certain elective reconstructions are appropriately treated with this technique. The lateral exposure to the popliteal artery is not technically demanding and offers a useful alternative for treatment of selected vascular problems.

Technetium 99m pyrophosphate quantitation of skeletal muscle ischemia and reperfusion injury

The study of ischemia and reperfusion injury in the extremity has been hampered by lack of an accurate method of measuring skeletal muscle injury. We used a bilateral isolated in vivo canine gracilis muscle model in 15 anesthetized dogs. The experimental muscles had 4, 6, or 8 hours of ischemia and 1 hour of reperfusion. The contralateral gracilis muscle served as a control. Technetium 99m pyrophosphate (99mTc-PYP), an agent which localizes in injured muscle cells, was used to quantitate canine skeletal muscle damage. After 6 hours of ischemia and 1 hour of reperfusion, there was a significant increase of 215% of 99mTc-PYP uptake in the experimental vs the control muscle. Experimental muscle uptake was 8% greater than control after 4 hours and 405% more after 8 hours of ischemia and reperfusion. Segmental distribution of 99mTc-PYP uptake showed localization to be greatest in the middle of the muscle at the entry site of the gracilis artery. Electron microscopic evaluation also documented this area to have undergone the most severe injury. Distal portions of the muscle did not show increased damage. Our results show that 99mTc-PYP effectively quantitates skeletal muscle ischemia and reperfusion injury. The pattern of 99mTc-PYP uptake suggests that considerable injury is caused during reperfusion.

Vascular complications related to drug abuse

Vascular complications resulting from drug abuse constitute a widespread and common clinical problem. A 3-year experience with 32 vascular complications (13 arterial, 19 venous) related to intravenous drug abuse is reported. Fourteen (48%) of the 29 patients in this series presented with septic vascular complications. These infections were a major cause of morbidity and mortality, resulting in two hospital deaths and a disrupted arterial repair. In addition, intra-arterial drug injection caused digital gangrene in two patients. Early recognition, diagnostic arteriography and venography, and planned therapeutic interventions are possible if a high level of suspicion is maintained.

The value of laser Doppler velocimetry and transcutaneous oxygen tension determination in predicting healing of ischemic forefoot ulcerations and amputations in diabetic and nondiabetic patients

The ability to predict successful healing of ulcerations and amputations of the ischemic forefoot continues to be a major clinical challenge, particularly in diabetic patients whose systolic Doppler ankle pressures are often artifactually elevated. We have used the techniques of laser Doppler velocimetry (LD) and transcutaneous oxygen tension monitoring (tcPO2) to quantitatively measure skin blood flow in the distal foot. Fifty-nine limbs were studied (48 patients), of which 37 (63%) were in diabetic and 22 (37%) in nondiabetic patients. All patients were admitted with ischemic ulcerations or gangrenous changes of the forefoot or digit. Twenty transmetatarsal or digital amputations were performed; the remainder of the lesions were débrided and allowed to heal by secondary intention or were covered by a skin graft. Before operation, the systolic pressure (expressed in millimeters of mercury, mean +/- SEM) was measured by Doppler technique at the ankle, and the ankle/arm index calculated (n = 59 limbs). The tcPO2 (also expressed in millimeters of mercury, mean +/- SEM) was measured from the dorsal foot (n = 56). The baseline skin blood flow velocity (SBFV) and pulse wave amplitude (PWA) were measured with the LD (expressed in millivolts, mean +/- SEM) on the plantar aspect of the foot (n = 53 limbs). Criteria for successful healing included a tcPO2 of more than 10 mm Hg, the combination of an LD-SBFV of more than 40 mV and an LD-PWA of more than 4 mV, and an ankle systolic pressure of more than 30 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)