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Biomedical subjects

M J Jacobs

Publications and source records attributed to M J Jacobs.

At least 109 records · Page 6Linked to original sources
PubMed1992

Capillary recruitment and pain relief on leg dependency in patients with severe lower limb ischemia.

BACKGROUND: Patients suffering from severe lower limb ischemia may experience pain relief on leg dependency despite the fact that dependency normally results in arteriolar vasoconstriction. To clarify this possible paradox, skin microcirculation of the limb was investigated in 75 patients with different stages of lower limb ischemia and in 12 asymptomatic subjects. METHODS AND RESULTS: Using nailfold capillary video microscopy, red blood cell-perfused capillary density and diameter and red blood cell velocity were assessed in supine and sitting positions. Capillary density increased by changing from the supine to the sitting position, especially in patients with limb-threatening ischemia (showing a 4.5-fold increase versus a 1.5-fold increase in asymptomatic subjects). In subjects without or with mild ischemia, capillary perfusion was two to four times lower in the sitting than in the supine position. In patients with limb-threatening ischemia, perfusion was strongly reduced, being slightly higher in the sitting position. Patients with relief of pain while sitting did not always have a higher capillary perfusion but did have a higher capillary density in the sitting position. CONCLUSIONS: The arteriolar postural vasoconstrictive mechanism at the nutritive level is still intact in subjects without or with mild ischemia but not in patients with severe ischemia. Capillary recruitment rather than disturbed arteriolar vasoconstriction could explain why patients with severe leg ischemia prefer leg dependency.

Adult↗
PubMed1992

Capillary microscopy in patients with vasospastic and arterial occlusive diseases.

Capillary microscopy and its application for diagnosis and therapeutic evaluation in patients with vasospastic and arterial occlusive disease are described in this report. Capillary microscopy is a noninvasive technique for measuring red blood cell velocity and for determining nutritional blood flow in the capillaries of the skin. This method can be applied in distinguishing patients with Raynaud's phenomenon from those with other disorders involving ischemia of the hand. In patients with atherosclerotic disease of the lower limb, microcirculatory observations can help determine how temperature increases and posturally induced microvascular constriction affect limbs with different degrees of ischemia. Capillary microscopy can also be used to help distinguish between patients who respond and those who do not respond to prolonged treatment for such disorders. Because capillary microscopy can be used to assess microcirculatory hemodynamics and autoregulatory mechanisms in cases of severe ischemia, it should be regarded as an essential tool in the evaluation of patients with upper- and lower-limb ischemia.

Journal Article↗
PubMed1992

Prosthetic graft placement and creation of a distal arteriovenous fistula for secondary vascular reconstruction in patients with severe limb ischemia.

Patients with lower limb ischemia who require reoperation for failed vascular reconstructive surgery can benefit from a surgical technique in which an artificial graft is used and an arteriovenous fistula is created at the site of the distal anastomosis, followed by ligation of the proximal vein. This technique was used in 30 patients who had undergone vascular reconstruction with bypasses from the femoral to the distal tibial, peroneal, or dorsal pedal arteries. Angiography showed occlusion of the superficial femoral and popliteal arteries in all patients with reconstitution of only one small segment in the anterior tibial (n = 12), posterior tibial (n = 11), peroneal (n = 5), or dorsal pedal artery (n = 2). All patients had rest pain and necrosis. Artificial grafts were required because of the absence of autogenous vein. Immediate postoperative graft patency was achieved in all 30 patients. The mean ankle/arm pressure index increased from 0.30 +/- 0.24 to 0.79 +/- 0.31 (p less than 0.01). Graft patency computed by the life-table method was 71% at both 1- and 2-year follow-up. Foot salvage was achieved in 25 of 30 patients after surgery. The results of this study indicate that an aggressive vascular surgical approach in patients with severe ischemia and previous failed bypass procedures is justified. In the absence of autogenous vein, the combination of a prosthetic graft and a distal arteriovenous fistula with ligation of the proximal vein increases graft patency.

Adult↗
PubMed1991

In-situ replacement and extra-anatomic bypass for the treatment of infected abdominal aortic grafts.

We reviewed the surgical results of 21 patients who had infected abdominal aortic grafts to determine the efficacy of in-situ graft replacement and extra-anatomic bypass in the management of these patients. Twelve patients had a primary perigraft infection, and nine had an infection secondary to an aortoenteric fistula (AEF). Whereas the infected graft was replaced with a new aortic prosthesis in 18 patients, an axillobifemoral bypass operation followed graft excision in three patients. Twelve of the graft replacement patients (two AEF patients) had a low-grade infection, with negative perigraft and blood cultures. All 12 patients were alive at a mean follow-up of 8 years. Two had required above-knee amputation because of severe occlusive disease, and one had required an axillobifemoral bypass because of reinfection. The remaining six graft replacement patients (five AEF patients) had severe graft infections, with positive perigraft fluid and blood cultures in which one or more bacteria were present. Five died of sepsis within 1 month of operation. The remaining patient, who later required an axillobifemoral bypass because of reinfection, was alive at follow-up 4.3 years after operation. The three patients (two AEF patients) who had axillobifemoral bypasses had severe graft infections, with positive perigraft fluid and blood cultures. They survived the extra-anatomic bypass operation and were alive at a mean follow-up of 4.5 years. We conclude that patients who have a low-grade graft infection and negative blood and perigraft cultures can be treated safely by graft excision and in-situ replacement with a new prosthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta, Abdominal↗
PubMed1991

Posturally induced microvascular constriction in patients with different stages of leg ischaemia: effect of local skin heating.

1. Skin microcirculation was investigated in 12 asymptomatic subjects and 76 patients, grouped according to their ankle-to-brachial systolic blood pressure index, in order to evaluate to what extent posturally induced microvascular constriction is dependent on the stage of leg ischaemia at different local skin temperatures. 2. Skin microcirculation was assessed in the supine and sitting position by using laser Doppler fluxmetry at unheated skin temperature and at 36 degrees C, and transcutaneous oximetry at 37 degrees C and 44 degrees C. 3. Skin perfusion and oxygenation diminished with decreasing ankle-to-brachial systolic blood pressure index. In healthy control subjects, perfusion and oxygenation were reduced when changing from the supine to the sitting position, but were enhanced in patients with severe leg ischaemia (ankle-to-brachial systolic blood pressure less than 30%), indicating disturbed posturally induced vasoconstriction. 4. Increasing the local skin temperature resulted in a higher perfusion and masked the posturally induced vasoconstriction in healthy subjects. In patients with severe leg ischaemia, however, perfusion was unaltered by the temperature increase, apparently because the microvessels were already maximally dilated. The induction of reactive hyperaemia produced no additional increase in perfusion or oxygenation. 5. It is concluded that posturally induced microvascular constriction in the skin is disturbed in patients with severe leg ischaemia (ankle-to-brachial systolic blood pressure index less than 30%). Disturbed microvascular constriction upon dependency was also seen in healthy subjects after local skin heating. This suggests that posturally induced vasoconstriction is mainly regulated by local mechanisms.

Adult↗
PubMed1991

Innominate artery occlusive disease: surgical approach and long-term results.

We reviewed our experience with 54 patients who underwent innominate artery revascularization during a 10-year period. Their age range was from 16 to 75 years (mean, 49.8 years). The innominate artery alone was involved in 21 patients (39%); the remaining patients had additional arch vessel obstructions. Before operation, neurologic symptoms occurred in 25 patients (46%), arm ischemia related to claudication and microembolization occurred in 8 patients (14%), a combination of symptoms occurred in 17 patients (32%), and no symptoms were noted in 4 patients (8%). The extrathoracic approach to surgery was used in 16 patients (30%). Eleven of the 38 patients in whom the intrathoracic approach was used had endarterectomy of the innominate artery; in three of those, the procedure was combined with left common carotid endarterectomy. Bypass grafts were used in the other 27 patients undergoing procedures with an intrathoracic approach; in six of those, bypass was combined with carotid endarterectomy. No operative deaths occurred. Perioperative revascularization failure occurred in four cases; all of those patients underwent a second revascularization procedure, with a secondary patency rate of 100%. In four patients, late occlusion was noted at 6 months and at 1, 1.5, and 10 years. One patient had a permanent perioperative neurologic deficit in the distribution of the left carotid artery after a combined common carotid endarterectomy/innominate endarterectomy procedure. No neurologic deficits were directly related to the innominate artery territory. Long-term actuarial survival was 83% at 10 years. Early and late graft failures were related to inadequate inflow in bypass grafts, progression of distal disease in arteritis, and primary closure in endarterectomy.

Adolescent↗
PubMed1991

Plasmapheresis in Raynaud's phenomenon in systemic sclerosis: a microcirculatory study.

Microcirculatory and haemorheological parameters were investigated before and after plasmapheresis in eighteen patients with secondary Raynaud's phenomenon based on progressive systemic sclerosis. After 4 plasmaphereses, once a week, all patients claimed explicit improvement of their complaints. Raynaud's phenomenon and especially the reaction upon cold provocation had disappeared and skin ulcers healed. Red blood cell (RBC) velocity increased significantly (p less than 0.001) after 4 weeks plasmapheresis. RBC aggregation and plasma viscosity were significantly lower (p less than 0.001) after the last plasmapheresis than before treatment. After 3 years four patients were still free of complaints, but in 14 patients the symptoms of Raynaud's phenomenon had reappeared after 6 to 9 months. The skin ulcers, however, did not return in these patients. RBC aggregation and plasma viscosity returned to the initial values after 9 months, while skin capillary blood flow remained significantly enhanced for 24 months. The finding that restoration of RBC aggregation and plasma viscosity to normal level is associated with enhanced skin capillary blood flow, indicates that disturbed haemorheology plays a role in the diminished skin blood flow, as observed in patients with secondary Raynaud's phenomenon. In these patients, plasmapheresis can be considered to treat severe ischemia of the digits.

Adult↗
PubMed1991

Spontaneous common iliac arteriovenous fistula manifested by acute renal failure: a case report.

Arteriovenous fistulas between the common iliac vessels resulting from spontaneous rupture of aneurysms are rare, with only 31 cases having been reported since 1971. Clinical diagnosis is possible when a unique set of findings is present, namely high-output cardiac failure, a pulsatile abdominal mass associated with a bruit or thrill, and unilateral arterial insufficiency or venous engorgement. Recently, with advancements in diagnostic techniques, the number of cases in which an arteriovenous fistula is found between the common iliac vessels has increased. Diagnosis can be difficult, however, as in the case of one of our patients in whom the predominant sign was acute renal failure. Other reports of renal failure or impairment in the presence of a common iliac fistula have also appeared. Awareness of this phenomenon can help the physician to establish the diagnosis when one or more of the classic signs are absent. Prompt diagnosis and surgical management have contributed to the high incidence of survival in patients with arteriovenous fistulas between the common iliac vessels.

Acute Kidney Injury↗
PubMed1990

Microcirculatory haemodynamics before and after vascular surgery in severe limb ischaemia--the relation to post-operative oedema formation.

To determine whether postoperative oedema could be predicted preoperatively by microcirculatory parameters, we studied nutritive capillary blood flow in 21 patients before and after limb salvage procedures. All patients had severe lower limb ischaemia and underwent femoro-popliteal or femoro-crural bypass surgery. The systolic ankle-branchial arm index and systolic toe pressure were used as macrocirculatory parameters. Intravital capillary microscopy was used to measure red blood cell (RBC) and peak RBC velocity and time to peak RBC velocity after release of a 1 min arterial occlusion in the nailfold of the toe. Transcutaneous pO2 was measured on the dorsum of the foot at rest, during oxygen inhalation and following a release of a 5 min occlusion. After surgery the mean systolic ankle-brachial index and systolic toe pressure and all transcutaneous pO2 parameters improved significantly (P less than 0.001). Mean peak RBC velocity increased from 0.156 mm/s to 0.310 mm/s (P less than 0.05), indicating that the reactive hyperaemic response in the capillary bed had improved. Eleven patients developed postoperative oedema. There were no differences in postoperative macro and microcirculatory parameters between the patients with oedema (n = 11) and those without oedema (n = 10). However, preoperatively RBC velocity and peak RBC velocity were significantly lower (P less than 0.05) and time to peak RBC velocity was significantly longer (P less than 0.01) in patients who developed oedema. These findings show that in patients with severe limb ischaemia vascular surgery improves both macro- and microcirculatory blood flow, but that these patients develop oedema after vascular surgery when microcirculatory blood flow is compromised preoperatively.

Aged↗
PubMed1990

Foot salvage and improvement of microvascular blood flow as a result of epidural spinal cord electrical stimulation.

Epidural spinal cord electrical stimulation has been suggested as an alternative treatment in patients with limb-threatening ischemia in whom vascular reconstructive surgery is not possible anymore. We studied the effects of epidural spinal cord electrical stimulation on microcirculatory blood flow in 20 patients with ischemic rest pain and ulcers. Angiography showed occluded crural arteries technically unsuitable for reconstructive surgery. Intravital capillary microscopy was used to assess capillary density and diameter and red blood cell velocity before and after a 1-minute period of arterial occlusion. After epidural spinal cord electrical stimulation 18 patients claimed immediate pain relief, which was confirmed by intravital capillary microscopy. Capillary density increased from 10 to 19/mm2 (p less than 0.001), red blood cell velocity increased from 0.088 to 0.496 mm/sec (p less than 0.001), and peak red blood cell velocity after arterial occlusion increased from 0.092 to 0.548 mm/sec (p less than 0.001). Two patients had no immediate pain relief; they did not show improvement of microcirculatory perfusion, and amputation was necessary. During the follow-up period (3 months to 3 years, mean 27 months), six other patients had recurrent ischemic pain, and amputation was necessary. In 12 patients pain relief continued, and ischemic ulcers healed; capillary microscopy confirmed improved microcirculatory blood flow. Microcirculatory parameters were significantly higher in respondents than in nonrespondents (p less than 0.001). Life-table analysis revealed a cumulative foot salvage of 80% and 56% after 1 and 2 years, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Effect of ketanserin on macrocirculatory and microcirculatory blood flow in patients with intermittent claudication. A prospective randomized study.

The effect of ketanserin on macrocirculatory and microcirculatory blood flow was investigated in a placebo-controlled, double-blind trial in 11 patients suffering from intermittent claudication using Doppler velocimetry and intravital skin capillary microscopy, respectively. After 1 year of treatment no significant change was observed either in the ketanserin or the placebo group. It appears that ketanserin has no significant effect on macrocirculatory blood flow and microcirculatory nutritional skin blood flow in patients with intermittent claudication.

Aged↗
PubMed1988

Epidural spinal cord electrical stimulation improves microvascular blood flow in severe limb ischemia.

Epidural spinal cord electrical stimulation (ESES) was performed on 10 patients with severe limb ischemia due to atherosclerotic disease. Microcirculatory parameters were assessed before and after ESES. Bright field microscopy was used to assess capillary diameters and red blood cell (RBC) velocity in the dorsum of the foot. Fluorescein microscopy was used with intravenously injected sodium fluorescein to study capillary density and sodium fluorescein appearance time in the dorsum of the toe. The systolic ankle/arm pressure ratio and toe pressure measurements were used as macrocirculatory parameters. After ESES, clinical improvement was confirmed by intravital microscopy. Capillary density increased (p less than 0.001), RBC velocity in capillaries already perfused before ESES increased from 0.054 mm/sec to 0.762 mm/sec (p less than 0.001), and sodium fluorescein appearance time decreased from 72 to 45 seconds (p less than 0.001). Capillary diameter did not change significantly so that the increase in RBC velocity may be interpreted as enhanced volume flow. Systolic ankle/arm pressure ratios and digital arterial pressure did not change significantly. The current results show that in patients with severe occlusive arterial disease of the lower limbs, ESES recruits capillaries not perfused in the control situation and enhances skin blood flow, improvements that may explain the beneficial clinical effects of ESES.

Aged↗
PubMed1987

Nomenclature of Raynaud's phenomenon: a capillary microscopic and hemorheologic study.

Hemorheologic parameters and nailfold capillaries were investigated in 72 patients with ischemic hand phenomena and 25 normal subjects. Red blood cell (RBC) aggregation and plasma viscosity were normal in all groups except in patients with secondary Raynaud's phenomenon; in this group, these parameters were significantly increased (p less than 0.001). The capillary density in the nailfold was significantly lower in patients with secondary Raynaud's phenomenon or acrocyanosis (p less than 0.001). The capillary diameters were slightly increased in patients with primary Raynaud's phenomenon, moderately increased in patients with acrocyanosis (more than twofold), and markedly increased in patients with secondary Raynaud's phenomenon (fourfold to fivefold). Nailfold velocity, before and after cold provocation, was decreased in all patients (p less than 0.001). The findings in this study support the conclusion that patients with primary and secondary Raynaud's phenomenon, acrocyanosis, or asphyxia digitorum can be distinguished by combining hemorheologic observations with morphologic and functional microscopic investigations of the nailfold capillaries. The nomenclature currently employed in our clinic can be used to define these different phenomena.

Adult↗