The relationship of postoperative hypertension to complications following carotid endarterectomy.

Severe postoperative hypertension following carotid endarterectomy is a serious and poorly understood clinical problem associated with an increased mortality rate and increased incidence of neurologic deficit. This complication, which is defined as a sustained elevation of systolic pressure greater than 200 mm Hg requiring pharmacologic control, occurred following 19% of 253 carotid procedures. Preoperative hypertension is the single most important determinate in the development of postoperative hypertension. The incidence of preoperative hypertension in patients who developed postoperative hypertension was 79.6% to 57.4% in patients who did not develop this complication (P < 0.01). There was a significantly increased incidence of neurologic deficit and operative mortality rate in the group who developed postoperative hypertension. There were five neurologic deficits in the group who developed postoperative hypertension, for an incidence of 10.2%. The incidence of neurologic deficit in the group who did not develop postoperative hypertension was 3.4%. The only deaths were in the postoperative hypertensive group. The hypertensive patient is at greater risk for postoperative hypertension, which is associated with increased neurologic morbidity and mortality.

Vascular endoscopy: useful tool or interesting toy.

A prospective protocol was designed to evaluate the efficacy and practically of intraluminal endoscopy in vascular reconstructive procedures. The choledochoscope and the arthroscope which utilize the Hopkins Optical System, as well as other available fiberoptic endoscopy units, were evaluated in 91 vascular reconstructions, including 42 carotid endarterectomies, 24 femoral artery reconstructions, 13 popliteal artery anastomoses, seven aortic and iliac procedures, one renal reconstruction, and one tibial reconstruction. In three cases the internal surface of an occluded limb of an aortic graft was examined endoscopically following thrombectomy. The optical resolution of the Hopkins Optical System was superior to the fiberoptic units. Vascular endoscopy required 5 minutes or less in 53 cases, between 5 to 10 minutes in 29 cases, and more than 10 minutes in nine. There were no infections. The single complication was a 1 cm linear tear in the intima of an internal artery. Positive findings were noted in 60 endoscopic studies, for an incidence of 66%. These consisted of intimal shreds in 47, elevated or irregular intimal flaps in 25, clot in five, and stenosis in three. In 26 cases the endoscopic findings were considered to be significant enough to possibly affect the ultimate outcome of the reconstruction.

Ureteral pathology associated with aortic surgery: a report of three unusual cases.

Intravenous pyelography is a necessary prerequisite to safe aortic surgery. Although urological complications of aortic pathology have been recognzized for 30 years, visualization of the urinary tract has not necessarily been routine practice in preoperative planning. With increasing frequency of aortic reconstruction, careful preoperative evaluation will continue to lower morbidity and mortality rates. Three unusual cases--one of perigraft ureteral fibrosis causing obstruction, one of ureteral obstruction due to retroperitoneal fibrosis, and one of ureterocutaneous fistula in a patient with an infected aortic prosthesis--are reviewed. These uncommon problems support the contention that information gained from routine excretory urograms will aid in careful preoperative assessment. Furthermore, the intravenous pyelogram will facilitate early recognition of postoperative urological complications.

Pneumatic tourniquet as a substitute for vascular clamps in distal bypass surgery.

The pneumatic tourniquet is an effective substitute for vascular clamps in tibial and popliteal artery surgery. Intimal trauma due to clamping is avoided. Because circumferential dissection of the vessel is not necessary, the vasa vasorum are preserved minimizing ischemic injury to the vessel wall. The technique has been employed in 40 distal popliteal and tibial reconsteal and tibial reconstructions during the past year with only one complication that may possibly be related to its use. Early patency was 92% at the patient's time of discharge from the hospital. In all four patients requiring below-knee amputation, primary wound healing and successful prosthetic rehabilitation were achieved. This technique appears to be safe and simplifies distal reconstructions for lower extremity ischemia.

Antithrombin deficiency--a cause of unexplained thrombosis in vascular surgery.

Antithrombin deficiencies may be the reason for seemingly unexplained thrombosis and graft failure. We treated seven patients who developed clotting difficulties as a result of antithrombin II and/or III deficiencies. In four, arterial thrombosis occurred after arterial reconstruction--three with occluded femoral grafts and one with runoff and digital vessel thrombosis that developed during profundoplasty. Two patients has spontaneous thrombosis of the arterial system of the vessels of the lower leg, and one developed ileofemoral phlebitis. Three patients had abnormally low levels of both antithrombin II and III, whereas two had low levels of antithrombin II only and two had low levels of antithrombin III. Of the four patients in whom this disorder occurred during vascular reconstruction, three experienced graft occlusion that resulted in below-knee amputation in two. There were no common predisposing factors. Antithrombin deficiency should be suspected when there is an unusual propensity to develop thrombus, when heparin cannot prolong coagulation time, and when measurements show reduced levels of antithrombin. Fresh frozen plasma should be given initially and long-term Coumadin therapy started. Early recognition and treatment is necessary to avoid limb loss or death.

The reoperation of choice for aortofemoral graft occlusion.

Restoration of circulation following occlusion of an aortofemoral graft was attempted in 50 limbs in 38 patients. Progressive arteriosclerosis in the femoral vessels was the cause of graft limb thrombosis in most instances. Profundaplasty was employed in 47 limbs and femoral-popliteal bypass in two to provide effective runoff. Inflow was established by thrombectomy in 30 of the 37 limbs in which it was attempted, and it was readily accomplished with a Fogarty catheter if carried out within a few weeks after graft occlusion. In the 20 limbs in which thrombectomy was either abandoned (seven or not feasible because of prolonged delay (13), new grafts were inserted (13) or extra-anatomic bypass was carried out by femoral-femoral (four) or axillary-femoral (three) techniques. Operative death occurred in one patient (2.6%) after transabdominal graft replacement, and only two other patients had significant complications with full recovery. Initial graft patency was achieved in 96.6% following thrombectomy and in 85% following new graft or extra-anatomic bypass. Cumulative patency was 75% after 3 years. Amputation was required in five of the limbs in which graft patency could not be maintained. Reoperation should be performed promptly after graft limb thrombosis. The procedure of choice is thrombectomy and profundaplasty through a simple groin incision.

Subclavian artery-to-innominate vein fistula: a case caused by subclavian venous catheterization.

Arteriovenous fistulas caused by subclavian vein catheterization occur rarely. Most subclavian vein catheters are inserted through an infraclavicular subclavian venipuncture with passage of a vessel dilator and peel-away sheath over a guidewire. We report a previously undescribed complication of this technique, namely, a right subclavian artery-to-right innominate vein fistula. The mechanism of injury was perforation through the opposing walls of the respective vein and artery due to stiffness of the vessel dilator that could not negotiate the curve from the subclavian vein to the innominate vein. Measures to avoid this complication are described.

Profundaplasty in perspective: limitations in the long-term management of limb ischemia.

The ultimate value of profundaplasty in the management of lower extremity ischemia was determined by multifactoral analysis of 239 operated limbs in 209 patients followed up to 110 months. In patients who underwent operation for claudication (n=83), patency without the need for subsequent revision or distal bypass was achieved in 77% at 5 years. By contrast, profundaplasty patency was maintained in only 23% of 154 limbs operated upon for salvage. The patient survival rate was 75% at 5 years and 56% at 7 years among the claudication group but only 29% at both 5 and 7 years in the limb salvage group. Of the 104 survivors in the limb salvage category, 43 required amputation, 79% within the first year, and 13 limbs were saved by additional revascularization procedures. Profundaplasty is a durable procedure for relief of claudication. However, it is significantly less effective in patients threatened with limb loss. When amputation is inevitable, effective profunda perfusion is essential for preservation of the knee joint.

Application of computed tomography for surveillance of aortic grafts.

BACKGROUND: This study was undertaken to assess the application of computed tomography (CT) for surveillance of aortic grafts. METHODS: Demographics, operative technique, and graft type and size at the time of implantation of aortic grafts in 178 patients were recorded. CT measurements of graft diameters were made with calipers. Data were analyzed by analysis of variance, multiple regression, and chi-squared methods. RESULTS: One hundred twenty-eight (72%) bifurcated grafts and 50 (28%) tube grafts were placed for aneurysmal disease (49%), aortoiliac occlusive disease (47%), ruptured aneurysm (2.3%), anastomotic aneurysm (1%), and graft aneurysm (0.6%). Mean implant time was 43.3 +/- 3.2 months. A total of 143 Dacron prostheses (74 woven, 69 knitted) and 35 polytetrafluoroethylene prostheses were placed. Mean percentage dilation was 49.2 +/- 4.0 for knitted prostheses, 28.5 +/- 3.0 for woven prostheses, and 20.6 +/- 1.9 for polytetrafluoroethylene prostheses compared with the graft implant size. A significant correlation was seen between graft dilation (more than 50%) and graft construction with knitted prostheses (p < 0.01, Tukey's range test). Complications detected by CT occurred in 24 (13.5%) patients including supragraft aneurysms (seven), distal anastomotic aneurysms (five), proximal anastomotic aneurysms (three), graft infections (two), perigraft fluid collections (two), graft aneurysm with thrombus and distal embolization (two), and nonvascular complications (three). CONCLUSIONS: CT is a useful modality for postoperative imaging of aortic prostheses. Routine surveillance may detect complications before they become clinically apparent.

Randomization of autogenous vein and polytetrafluorethylene grafts in femoral-distal reconstruction.

A randomized, prospective, controlled study comparing autogenous saphenous vein and polytetrafluoroethylene (PTFE) grafts in infrainguinal arterial reconstructions has been initiated in three different institutions. A total of 446 operative procedures were divided into six groups, depending on the site of distal bypass insertion into the popliteal or an infrapopliteal artery and on whether the patient received a randomized vein or PTFE graft or an obligatory PTFE graft. The randomized saphenous vein graft patency to infrapopliteal arteries was significantly better (P less than 0.005) at 2 1/2 years than the patency of randomized or obligatory PTFE grafts to the same level. No significant differences between randomized vein grafts and randomized or obligatory PTFE grafts in the femoropopliteal position could be demonstrated up to 2 1/2 years, either above or below the knee. The need for such a study and the limitations of this preliminary report are discussed. The requirement for longer observation of greater numbers of cases is stressed. A current plan for usage of the PTFE graft in the lower extremity is presented.

Revascularization of the ischemic kidney.

Although acute renal artery obstruction causes cessation of kidney function, the viability of the nephron is often maintained by collateral circulation. When renal artery blood flow is restored, filtration is resumed and the resulting acute tubular necrosis is gradually resolved as renal tubular cells regenerate. We have observed several different mechanisms of acute renal artery obstruction resulting in anuric renal failure: temporary suprarenal placement of an aortic clamp during absominal aneurysmectomy, resulting in bilateral renal artery occlusion; embolus, presumably of cardiac origin, to a solitary kidney; and thrombosis of the distal aorta extending to a level proximal to the renal arteries. There is no correlation between the duration of renal artery occlusion and the viability of kidney parenchyma. Viability of the kidney can only be determined by visual inspection at operation and response to revascularization. When vascular obstruction is a possible cause of acute anuric renal failure, immediate angiography is indicated. If a correctable vascular lesion is identified, operative intervention is mandatory.

Intraoperative streptokinase. An adjunct to mechanical thrombectomy in the management of acute ischemia.

Streptokinase was injected directly into the arterial tree following balloon-catheter embolectomy on 13 occasions to remove residual thrombus that could not be mechanically retrieved in 12 patients with imminent limb (ten patients) or kidney (two patients) necrosis. Effective lysis, confirmed by arteriography, pulse return, and increased ankle pressures, was achieved in 11 trials (85%). Bleeding complications, minor in three patients and severe in two patients, were ascribed to systemic lysis although other factors were contributory. One of five deaths was related to therapy. Six limbs were salvaged. The average total dose of streptokinase used, 110,000 units, was given in intermittent boluses of 25,000 to 50,000 units injected below a clamp placed to temporarily occlude distal circulation. Safe application of this technique requires intraoperative monitoring of coagulation parameters, aggressive replacement therapy, and prudent patient selection. This preliminary experience suggests that intraoperative lytic therapy (1) is an effective method for clearing thrombus not amenable to mechanical extraction and (2) may improve patency and tissue salvage.

Comparison of caval filters in the management of venous thromboembolism.

Over a seven-year period, 38 Mobin-Uddin MU and 33 Kim-Ray Greenfield KG vena cava filters were inserted in 71 patients with no substantial complications or deaths directly related to the surgical procedure. Thirteen of the 16 early deaths were due to progression of associated diseases. The remaining three deaths were caused by pulmonary emboli and occurred in each instance after insertion of a MU filter. None of the 14 late deaths were related to the caval filter or sequellae of venous thrombosis. Inferior vena cava patency was objectively assessed in 36 patients by cavagram (22) or autopsy (14). Caval patency of 95% (18 of 19) in those with KG filters was significantly greater than the 47% patency (eight of 17) seen with MU devices (P less than .01). Gray scale ultrasound, when successful in visualizing the vena cava, was found to be a reliable indicator of patency. Venous stasis phenomena were noted in 50% of those with a patent cava and in 70% of those with an occlusion. Thus, it is not surprising that edema was found in only 38% of the patients as compared with 75% of the patients with the MU filter. Both of these devices are safe to insert. However, on the basis of superior patency rate, lower incidence of stasis phenomena, and the absence of recurrent pulmonary emboli in our series, we prefer insertion of a KG filter when caval interruption is required.

Periorbital ultrasound findings. Hemodynamics in patients with cerebral vascular disease.

The direction of supraorbital and frontal artery flow and its response to compression of the superficial temporal, facial, and angular arteries were measured in 250 carotid arteries in 114 patients. All patients had arch and/or selective carotid arteriography. The carotid arteries were placed into the following three groups: hemodynamically normal, greater than 60% occlusion of the internal carotid artery, and total occlusion of the internal carotid artery. The test's accuracy was 94.5% in the hemodynamically normal group, 68.8% in the totally occluded group, and only 51.4% in the group with hemodynamically significant stenosis. Although the carotid Doppler examination is not reliable in detecting hemodynamically significant lesions of the internal carotid artery, it is valuable in assessing the adequacy of collateral cerebral circulation.

White clot syndrome. Peripheral vascular complications of heparin therapy.

Heparin sodium-induced thrombosis is insidious and difficult to diagnose. If untreated, it results in death or major amputation. We have treated seven patients with thromboses resulting from platelet aggregation induced by heparin. Four patients had acute arterial ischemia of the lower extremity, venous gangrene developed in two, and one patient had an occluded autogenous vein femoral popliteal bypass in the immediate postoperative period. The platelet count was noticeably reduced in affected patients. White platelet thrombi were noted in four patients, three of whom had acute arterial occlusion. A white thrombus was the cause of immediate failure of a femoral popliteal graft. Electron microscopic examination of these thrombi demonstrated predominantly fibrin platelet aggregates with an occasional entrapped WBC and a rare RBC. All patients receiving heparin therapy must have platelet counts performed regularly. If thrombocytopenia is detected, platelet aggregation studies are indicated. When abnormal platelet aggregation is noted, heparin therapy should be reversed with protamine sulfate and the patient treated with low-molecular-weight dextran and warfarin sodium.

Acute limb ischemia following aortic reconstruction. A preventable cause of increased mortality.

Acute limb ischemia following aortic reconstruction is primarily related to intraoperative technical errors and is associated with significantly increased mortality. Elective aortic reconstruction was performed on 262 patients between 1975 and 1981. Surgical indications were aneurysm in 84 patients (32%), occlusive disease in 125 (48%), and both of these in 53 (20%). Acute limb ischemia developed postoperatively in 27 patients (10.3%); it was noted at the conclusion of the operation in five (19%) of them and within the first 48 hours in 22 (81%). The mortality was greater in the combined aneurysm and occlusive disease group than in the aneurysm-only and occlusive disease-only groups, primarily because of an increased incidence of myocardial disease in the combined group. Postoperative limb ischemia was mainly a result of technical error and resulted in increased mortality in all groups.

Fasciotomy: an appraisal of controversial issues.

Fourty-eight fasciotomies performed for conventional indications were analyzed, focusing primarily on the reliability of clinical diagnosis and the effectiveness of the operative technique. Decompression was accomplished immediately after hospital admission or arterial repair in 27 patients and deferred until the appearance of signs and symptoms in 21 others. Myoneural degeneration occurred in the delayed group only as a result of massive trauma or when obvious signs of compartment syndrome were ignored. A high index of suspicion and careful attention to clinical findings were reliable for establishing the diagnosis and indicating the timing of myofascial decompression. Tissue-pressure measurements were not used. The technique of four-compartment fasciotomy through a single lateral incision without fibulectomy was used in 21 limbs and compared with 18 four-compartment fasciotomies utilizing conventional methods. This procedure is rapid, simple, effective, and atraumatic and provides excellent exposure for direct visualization and selective decompression of all compartments and their individual muscles.

Abdominal aortic aneurysm and retroperitoneal fibrosis. Ultrasonographic diagnosis and treatment.

Until changes of ureteric or vascular compromise are noted, retroperitoneal fibrosis usually goes unnoticed. When symptomatic retroperitoneal fibrosis has been associated with abdominal aortic aneurysm, ureteral involvement has uniformly been present. Three cases demonstrate a new ultrasonographic picture that can aid in early identification of retroperitoneal fibrosis before complications are manifest. In patients with abdominal aortic aneurysms, routine sonography may identify unsuspected retroperitoneal fibrosis, a factor that may be important in preoperative planning for safe surgical intervention.

Profundapopliteal collateral index. A guide to successful profundaplasty.

The response to profundaplasty was evaluated in 232 limbs (163 patients) and correlated with segmental pressures and operative flow measurements. Of 150 limbs operated on for rest pain or ischemic necrosis, an inflow procedure (aortofemoral, femorofemoral, etc) combined with profundaplasty was successful in achieving limb salvage in 80 of 96 limbs (83%), but after profundaplasty alone only 26 of 54 limbs (48%) were salvaged. Using segmental pressure measurements, an index of the resistance of the profundapopliteal collateral system (PPCI) was calculated from the segmental pressure decrease across the knee, and demonstrated an inverse correlation with circulatory improvement. When profundaplasty was performed alone, successful limb salvage was associated with a mean PPCI of .18, compared with .46 in the group with unsatisfactory results. The PPCI is an accurate predictor of the hemodynamic potential of the geniculate collaterals and is useful in the selection of patients for profunda repair.

Ergotism.

Severe extremity ischemia developed in four patients who had ingested methysergide maleate or ergot for the relief of headache. Symptoms involved the upper extremity in two patients and the lower extremity in two. Spontaneous reversal of the ischemic picture was obtained by simple discontinuation of ergot in most instances, although intra-arterial vasodilators were used in one case. Angliography disclosed arterial spasm and was a useful adjunct in confirming the cause of ischemia in each of the patients. It was especially useful when a history or ergot ingestion was not immediately available.