Zafar Jamil

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.

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.

Duplex ultrasound velocity criteria for the stented carotid artery

OBJECTIVES Ultrasound velocity criteria for the diagnosis of in-stent restenosis in patients undergoing carotid artery stenting (CAS) are not well established. In the present study, we test whether ultrasound velocity measurements correlate with increasing degrees of in-stent restenosis in patients undergoing CAS and develop customized velocity criteria to identify residual stenosis > or =20%, in-stent restenosis > or =50%, and high-grade in-stent restenosis > or =80%. METHODS Carotid angiograms performed at the completion of CAS were compared with duplex ultrasound (DUS) imaging performed immediately after the procedure. Patients were followed up with annual DUS imaging and underwent both ultrasound scans and computed tomography angiography (CTA) at their most recent follow-up visit. Patients with suspected high-grade in-stent restenosis on DUS imaging underwent diagnostic carotid angiograms. DUS findings were therefore available for comparison with luminal stenosis measured by carotid angiograms or CTA in all these patients. The DUS protocol included peak-systolic (PSV) and end-diastolic velocity (EDV) measurements in the native common carotid artery (CCA), proximal stent, mid stent, distal stent, and distal internal carotid artery (ICA). RESULTS Of 255 CAS procedures that were reviewed, 39 had contralateral ICA stenosis and were excluded from the study. During a mean follow-up of 4.6 years (range, 1 to 10 years), 23 patients died and 64 were lost. Available for analysis were 189 pairs of ultrasound and procedural carotid angiogram measurements; 99 pairs of ultrasound and CTA measurements during routine follow-up; and 29 pairs of ultrasound and carotid angiograms measurements during follow-up for suspected high-grade in-stent restenosis > or =80% (n = 310 pairs of observations, ultrasound vs carotid angiograms/CTA). The accuracy of CTA vs carotid angiograms was confirmed (r(2) = 0.88) in a subset of 19 patients. Post-CAS PSV (r(2) = .85) and ICA/CCA ratios (r(2) = 0.76) correlated most with the degree of stenosis. Receiver operating characteristic analysis demonstrated the following optimal threshold criteria: residual stenosis > or =20% (PSV >or =150 cm/s and ICA/CCA ratio > or =2.15), in-stent restenosis > or =50% (PSV > or =220 cm/s and ICA/CCA ratio > or =2.7), and in-stent restenosis > or =80% (PSV 340 cm/s and ICA/CCA ratio > or =4.15). CONCLUSIONS Progressively increasing PSV and ICA/CCA ratios correlate with evolving restenosis within the stented carotid artery. Ultrasound velocity criteria developed for native arteries overestimate the degree of in-stent restenosis encountered. These changes persist during long-term follow-up and across all grades of in-stent restenosis after CAS. The proposed new velocity criteria accurately define residual stenosis >or =20%, in-stent restenosis >or =50%, and high-grade in-stent restenosis > or =80% in the stented carotid artery.

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.

Cognitive changes after surgery vs stenting for carotid artery stenosis

OBJECTIVES Cognitive function has not been evaluated systematically in the context of carotid endarterectomy (CEA) versus carotid artery stenting (CAS). Cognitive decline can occur from microembolization or hypoperfusion during CEA or CAS. Carotid revascularization may, however, also improve cognitive dysfunction resulting from chronic hypoperfusion. We compared cognitive outcomes in consecutive asymptomatic patients undergoing CAS or CEA. METHODS This is a prospective nonrandomized single-center study of patients with asymptomatic carotid stenosis ≥ 70% undergoing CAS or CEA using standard techniques. Neurologic symptoms were evaluated by history, physical examination, and the National Institutes of Health Stroke Scale. A 50-minute cognitive battery was performed 1 to 3 days before and 4 to 6 months after CEA/CAS. The tests (Trail Making Tests A/B, Processing Speed Index (PSI) of the Wechsler Adult Intelligence Scale - Third Edition (WAIS-III), Boston Naming Test, Working Memory Index (WMI) of the Wechsler Memory Scale - Third Edition (WMS-III), Controlled Oral Word Association, and Hopkins Verbal Learning Test) for six cognitive domains (motor speed/coordination and executive function, psychomotor speed, language (naming), working memory/concentration, verbal fluency, and learning/memory) were conducted by a neuropsychologist. The primary analysis of impact of treatment modality was a normalized cognitive change score. RESULTS Forty-six patients underwent prepost testing (CEA = 25, CAS = 21). Women comprised 36% of the cohort, mean preprocedural stenosis was 84%, and 54% were right-sided lesions. All patients were successfully revascularized without periprocedural complications. The scores for each test improved after CEA except WMI, which decreased in 20 of 25 patients. Improvement occurred in all tests after CAS except PSI, which decreased in 18 of 21 patients. In addition to comparing the changes in individual test scores, overall cognitive change was measured by calculating the change in composite cognitive score (CCS) postprocedure versus baseline. To compute the CCS, the raw scores from each test were transformed into z scores and then averaged to calculate each patients composite score. The composite score at baseline was then compared with that from the postprocedure testing. The CCS improved after both CEA and CAS, and the changes were not significantly different between the groups (.51 vs .47; P = NS). CONCLUSIONS Carotid revascularization results in an overall improvement in cognitive function. There are no differences in the composite scores of five major cognitive domains between CEA and CAS. When individual tests are compared, CEA results in a reduction in memory, while CAS patients show reduced psychomotor speed. Larger studies will help confirm these findings.

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.

Femoral venous trauma: Techniques for surgical management and early results

During a 4 year period (1979 through 1983), 181 major arterial (69 percent) and 81 venous (31 percent) injuries were treated surgically. Of the venous injuries, 24 (30 percent) involved the femoral veins (9 common femoral, 15 superficial femoral). Management of these femoral venous injuries included lateral venorrhaphy in 10 cases (42 percent), venous patch angioplasty in 5 cases (21 percent), end-to-end anastomosis in 4 cases (17 percent), interposition autogenous saphenous vein grafts in 3 patients (12 percent), and ligation in 2 cases (8 percent). One case that included common femoral venous ligation and one that included a failed interposition saphenous vein graft in the superficial femoral vein subsequently were managed with in situ saphenous vein bypass. For one interposition saphenous vein graft repair of the common femoral vein we utilized the spiral vein graft technique. Excluding one early death from associated injuries and one superficial femoral venous injury managed by ligation without postoperative complications, 17 of 23 (74 percent) femoral venous repairs were judged patent postoperatively (13 confirmed by venography and 4 by noninvasive testing). The adjuvant use of intermittent pneumatic calf compression and low molecular weight dextran appears to have been beneficial in maintaining patency of the femoral venous repairs. Early clinical follow-up demonstrated the presence of edema in 6 of 8 cases (75 percent) initially treated by ligation or complicated by postoperative occlusion. Early postoperative edema, present in 4 of 17 (24 percent) patients with patent venous repairs, had resolved by the time of discharge. We recommend routine repair of femoral venous injuries. When significant edema or ischemia develop following obligatory venous ligation or postoperative occlusion of a venous repair, revision or venous bypass should be considered.

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.

Fallibility of doppler ankle pressure in predicting healing of transmetatarsal amputation

Abstract Sixty transmetatarsal amputations performed in 52 adult male patients for arterial insufficiency were studied to assess reliability of Doppler ankle systolic blood pressure (DABP) measurements in predicting healing. DABP were -60 mm Hg in 51 amputations (Group III). Forty-five (75%) of the amputations healed; 50% in Group I, 80% in Group II, and 76% in Group III. DABP for healed amputations was 115 ± 10 mm Hg, while DABP for nonhealed amputations was 96 ± 11 mm Hg and these values were not significantly ( P > 0.05) different. Healing occurred in 5 amputations with dependent rubor confined to the forefoot, while 9 of 12 amputations failed to heal when rubor was present at a higher level. Five of the fifteen nonhealed amputations had cellulitis involving the dorsum of the foot, while only 3 of the 45 healed amputations had similar clinical findings. DABP should not be used as an absolute guide to predict healing of transmetatarsal amputation. Low DABP does not contraindicate transmetatarsal amputation, while higher DABP does not guarantee success. Clinical assessment may be used reliably to predict healing.

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.