Intermittent calf and foot compression increases lower extremity blood flow.

PURPOSE: Although foot compression increases foot skin perfusion and calf compression increases popliteal artery blood flow, these compression techniques have not been evaluated in combination. The purpose of this study was to evaluate whether calf and foot compression applied separately and simultaneously increase popliteal artery blood flow and/or foot skin perfusion, and to assess the relative merits of compression in patients with superficial femoral artery occlusion. METHODS: Twenty-two legs from 12 normal volunteers with ankle/brachial indices (ABIs) > 0.96, and 10 legs from 7 claudicator patients with angiographically documented superficial femoral artery (SFA) occlusion and patent popliteal arteries with ABIs < 0.8 were studied in the sitting position. Calf and foot cuffs connected to a rapidly inflating and deflating timed-pressure pump (Art-Assist-AA 1000; ACI Medical Inc., San Marcos, California) were applied to the subject in the sitting position. Skin blood flow of the great toe was measured with a laser doppler (Laserflo model BPM 403A; TSI Inc., St. Paul, Minnesota), and popliteal artery blood flow was measured using duplex ultrasonography (ATL-Ultramark 9; Advanced Tech Laboratory, Bothell, Washington). Foot and calf compression was applied separately and simultaneously at 120 mm Hg pressure, with a 10-second inflation and 20-second deflation cycle. Popliteal artery blood flow and foot skin perfusion were recorded and the mean of 6 cycles calculated. RESULTS: Precompression popliteal artery blood flow (mL/min) for volunteers was 38.86 +/- 3.94, and for patients was 86.30 +/- 14.55 (P = 0.001). Precompression foot skin perfusion (mL/min/ 100/g tissue) for volunteers was 1.67 +/- 0.29, and for patients was 4.00 +/- 0.92 (P = 0.01). With the application of calf, foot, and simultaneous calf and foot compression, the popliteal artery blood flow increased in volunteers by 124%, 54%, and 173%, respectively, and in patients by 76%, 13%, and 50%. Foot skin perfusion increased in volunteers by 260%, 500%, and 328%, respectively, and in patients by 116%, 246%, and 188%. Relative increases in popliteal artery blood flow and foot skin perfusion were higher in volunteers compared with patients during compression; however, the absolute values for foot skin perfusion and popliteal artery blood flow were consistently higher in patients. CONCLUSIONS: Measured in the sitting position, the resting popliteal artery blood flow and foot skin perfusion are greater in patients with SFA occlusion compared with normal volunteers. Following compression, popliteal artery blood flow and foot skin perfusion increased in both groups, but relatively more in volunteers. Increases in popliteal artery blood flow are significantly higher with calf compression than with foot compression for both groups. A patent SFA allows for additive increases in popliteal artery blood flow with simultaneous foot and calf compression in normal persons, whereas this is not observed in patients. However, the increases in foot skin perfusion in patients with an occluded SFA parallel the increases shown in normal volunteers, with separate and simultaneous foot and calf compression.

The role of endoscopic retrograde cholangiopancreatography with laparoscopic cholecystectomy in the management of choledocholithiasis.

Perioperative endoscopic retrograde cholangiopancreatography (ERCP) and sphincterotomy (ES) offer the ability to remove common bile duct stones (CBDS) and still use the laparoscopic technique for cholecystectomy. The accuracy of predicting choledocholithiasis has been variable in several studies. The indications and complications of perioperative ERCP and ES with laparoscopic cholecystectomy (LC) are presented here. Between 6/1/90 and 11/11/93, 484 LC were performed at Santa Barbara Cottage Hospital. A total of 38 patients underwent perioperative ERCP; 33 patients underwent preoperative ERCP with 3/33 (9%) failing to cannulate the ampulla; 15 patients had choledocholithiasis; and 14/15 (93%) were cleared by ES. Fifteen patients had a normal CBD on ERCP. There were no deaths in this group of patients, seven of 38 (18%) had complications, including bleeding and post ERCP hyperamylasemia. Patients who had a normal CBD and underwent preoperative ERCP (9/15, 60%) had a history of gallstone pancreatitis or hyperamylasemia that was resolved or resolving before ERCP. Patients without stones on ERCP or cholangiogram (11/15, 73%) had a normal bilirubin (avg. 1.0 mg/dL; Range 0.4-2.3). Patients with choledocholithiasis (8/15, 53%) had a history of jaundice or elevated bilirubin before ERCP (avg. 2.59 mg/dL; range 0.2-9.3). ERCP with ES and laparoscopic cholecystectomy is a safe and effective method for the management of symptomatic cholelithiasis with choledocholithiasis. A history of gallstone pancreatitis or hyperamylasemia that is resolving or resolved in the absence of an elevated bilirubin does not require preoperative ERCP before LC with cholangiogram.

Retrograde aortic dissection after bilateral iliac artery stenting: a case report and review of the literature.

We report a case of retrograde aortic dissection after bilateral iliac artery stenting. A 63-year-old black woman underwent aortography with balloon angioplasty of bilateral common iliac artery lesions and subsequent vascular stent placement. The patient developed an acute aortic dissection from the level of the aortic bifurcation to the left subclavian artery. This case is presented to call attention to the previously unreported complication of retrograde aortic dissection after bilateral iliac artery angioplasty and stent placement presenting as acute chest pain.

Catechol estrogen adducts.

Reaction of estrone-3,4-o-quinone with ethanethiol and glutathione leads to the formation of 4-hydroxyestrone-2-thioethers. Incubations of [1-3H]hydroxyestrone with rat liver microsomes and NADPH in the presence of glutathione results in the formation of 4-hydroxyestrone-S-glutathione with no release of tritium in the water indicating GSH addition to C-2 of 4-hydroxyestrone.

Regioselective reaction of thiols with catechol estrogens and estrogen-O-quinones.

Incubations of [3H]estradiol and [3H]2-hydroxyestradiol (2-OHE2) with rat liver microsomes and mushroom tyrosinase were carried out in the presence of glutathione and 2-mercaptoethanol. A ratio of about 3.5:1 for the C-4 and C-1 thioether conjugates of 2-OHE2 was observed. Chemical reaction of estradiol-2, 3-O-quinone with various thiols showed that alkyl and phenyl thiols gave about a 1:1 ratio of C-4 to C-1 thioethers. However, reaction of the O-quinone with 4-nitrothiophenol gave a C-4/C-1 ratio of 0.25 while 4-bromothiophenol gave a C-4/C-1 ratio of 4.0. These studies suggest that the regioselectivity of the reaction of thiols with estrogen catechols and O-quinones may be dependent on the nature of the thiol compounds and less on steric hindrance.

Are both color-flow duplex scanning and cerebral arteriography required prior to carotid endarterectomy?

In an attempt to eliminate the morbidity, mortality, and cost associated with arteriography, surgeons are relying increasingly on duplex scanning of the extracranial arteries as the primary preoperative evaluation prior to carotid endarterectomy (CEA). This study was initiated to evaluate the need for cerebral arteriography in the preoperative evaluation of patients for CEA. One hundred five patients undergoing 114 CEA procedures are included in a retrospective review to determine whether the addition of cerebral arteriography changed the operative management of these patients. In 58 of 105 patients (55%), color-flow duplex scanning and cerebral arteriography were performed in the workup prior to CEA. In four patients a discrepancy was found between the duplex results and the arteriogram, leading to a change in the operative approach in two. The remaining 47 patients (45%) underwent color-flow duplex scanning as the definitive preoperative study; the surgical management was altered because of the operative findings in one patient. Although color-flow duplex scanning does not provide absolute concordance with cerebral arteriography, in most instances it can be used as the definitive preoperative study prior to CEA. We define the indications for cerebral arteriography in patients undergoing CEA.

Microcirculatory compensation to progressive atherosclerotic disease.

The precapillary resistance in the skin of the foot increases with standing. This mechanism, termed the venoarterial reflex (VAR) restricts arterial inflow, and avoids an excessive rise in capillary pressure. This study tests the hypothesis that there is microcirculatory compensation to atherosclerotic disease of increasing severity. Foot skin perfusion (FSP) was measured in 100 limbs with a laser Doppler placed on the plantar aspect of the great toe. Limbs were categorized as normal (n = 31) with an ankle brackial index (ABI) > or = 0.96, claudicants (n = 42) ABI 0.5-0.86, and critical ischemia (n = 27) with an ABI < or = 0.49 or a pulse volume recording consistent with severe peripheral vascular disease and symptoms of rest pain or tissue loss. Segmental Doppler pressures and pulse volume recordings were performed prior to laser Doppler measurements. Subjects with clinical signs or symptoms of chronic venous insufficiency were excluded. The resting foot skin perfusion was measured in the horizontal and dependent position, with the patient supine and sitting. Comparisons within categories were done using Wilcoxon matched pairs signed rank test and between groups with Mann-Whitney U test for unpaired data. Differences were considered significant if they exceeded the 95% confidence level (p value < or = 0.05). Resting supine skin perfusion was similar between nondiabetic normals and claudicants and diabetic normals and claudicants. There was a significant decrease in the foot skin perfusion (mean FSP +/- SEM) in the normal limb with a change from the supine (7.8 +/- 2.2 ml/min/100 g) to the dependent (2.8 +/- 0.6 ml/min/100 g) position indicating an intact VAR. This was absent in 33% of the limbs with claudication. Limbs with critical ischemia demonstrated an increase in FSP with dependency (supine 4.0 +/- 1.0 ml/min/100 g) versus dependent (8.4 +/- 1.8 ml/min/100 g) and was present in both diabetic and nondiabetic limbs. Microcirculatory compensation occurs early in atherosclerotic limbs. Although supine FSP is similar in normals and claudicants, a greater percentage of claudicants demonstrate a loss of the VAR. Critically ischemic limbs have increased FSP in the dependent position. These observations indicate that there are microcirculatory alterations in limbs with claudication and assist in explaining why patients with ischemic rest pain obtain relief and develop edema with dependency.

The contributions of arterial and venous volumes to increased cutaneous blood flow during leg compression.

Intermittent lower extremity compression increases cutaneous blood flow. The source of this increased perfusion and, the influence of physical activity on stimulated foot skin perfusion has not been elucidated. The purpose of this study is to determine the arterial and venous contributions to augmented cutaneous blood flow during foot and leg compression, and to evaluate whether physical activity influenced the response to compression. Fifty limbs from 29 normal volunteers were studied in the sitting position. Their daily physical activity was categorized as active if they exercised > or =3 days/week or sedentary if they exercised < or =3 days/week. Inflatable foot and calf compression cuffs attached to a timed-pressure pump (Art-assist AA 1000, ACI, Inc., San Marcos, CA) were applied to the subject's leg and set to deliver 120 mmHg pressure with a 10-sec deflation cycle. Skin perfusion of the great toe was recorded by a laser Doppler (Laserflo Model BPM 403, TSI, Inc., St. Paul, MN). Total perfusion with compression (A), retrograde venous perfusion (B), and compression artifact (C) was recorded. Mean values for A, B, and C and the differences between the two groups were analyzed using multivariate multiple comparison statistical method. The mean baseline skin perfusion was 3.96 +/- 0.91, and mean total stimulated skin perfusion (A) was 9.23 +/- 2.13. With arterial inflow obliterated and compression applied, mean skin perfusion (B) was 1.96 +/- 0.44. The sedentary group had a mean resting perfusion of 1.64 +/- 0.28 and mean stimulated value (A) of 2.29 +/- 0.37 ml/min/100 gm tissue. The active group had a mean resting perfusion of 28.26 +/- 0.91, and stimulated value (A) of 32.65 +/- 4.47 ml/min/100 gm tissue. These differences in the mean skin perfusion between the two groups were significant. It is concluded that in normals, the majority of increased perfusion is from increased arterial inflow. There is a larger resting foot skin perfusion in active individuals and they have quantitatively greater stimulated inflow compared to sedentary individuals.

High-pressure, rapid-inflation pneumatic compression improves venous hemodynamics in healthy volunteers and patients who are post-thrombotic.

PURPOSE: Deep vein thrombosis (DVT) is a preventable cause of morbidity and mortality in patients who are hospitalized. An important part of the mechanism of DVT prophylaxis with intermittent pneumatic compression (IPC) is reduced venous stasis with increased velocity of venous return. The conventional methods of IPC use low pressure and slow inflation of the air bladder on the leg to augment venous return. Recently, compression devices have been designed that produce high pressure and rapid inflation of air cuffs on the plantar plexus of the foot and the calf. The purpose of this study is to evaluate the venous velocity response to high-pressure, rapid-inflation compression devices versus standard, low-pressure, slow-inflation compression devices in healthy volunteers and patients with severe post-thrombotic venous disease. METHOD: Twenty-two lower extremities from healthy volunteers and 11 lower extremities from patients with class 4 to class 6 post-thrombotic chronic venous insufficiency were studied. With duplex ultrasound scanning (ATL-Ultramark 9, Advanced Tech Laboratory, Bothell, Wash), acute DVT was excluded before subject evaluation. Venous velocities were monitored after the application of each of five IPC devices, with all the patients in the supine position. Three high-pressure, rapid-compression devices and two standard, low-pressure, slow-inflation compression devices were applied in a random sequence. Maximal venous velocities were obtained at the common femoral vein and the popliteal vein for all the devices and were recorded as the mean peak velocity of three compression cycles and compared with baseline velocities. RESULTS: The baseline venous velocities were higher in the femoral veins than in the popliteal veins in both the volunteers and the post-thrombotic subjects. Standard and high-pressure, rapid-inflation compression significantly increased the popliteal and femoral vein velocities in healthy and post-thrombotic subjects. High-pressure, rapid-inflation compression produced significantly higher maximal venous velocities in the popliteal and femoral veins in both healthy volunteers and patients who were post-thrombotic as compared with standard compression. Compared with the healthy volunteers, the patients who were post-thrombotic had a significantly attenuated velocity response at both the popliteal and the femoral vein levels. CONCLUSION: High-pressure, rapid-inflation pneumatic compression increases popliteal and femoral vein velocity as compared with standard, low-pressure, slow-inflation pneumatic compression. Patients with post-thrombotic venous disease have a compromised hemodynamic response to all IPC devices. However, an increased velocity response to the high-pressure, rapid-inflation compression device is preserved. High-pressure, rapid-inflation pneumatic compression may offer additional protection from thrombotic complications on the basis of an improved hemodynamic response, both in healthy volunteers and in patients who were post-thrombotic.