Biomedical subjects

J J Schuler

Publications and source records attributed to J J Schuler.

At least 19 recordsLinked to original sources

PubMed2000

Free tissue transfer provides durable treatment for large nonhealing venous ulcers.

BACKGROUND: Most venous ulcers (VUs) will heal with conventional treatment, which focuses on improving regional venous hemodynamics. This treatment, however, often fails to heal large, recurrent VUs that are associated with severe lipodermatosclerosis (LDS). These complicated ulcers may require correction of local venous hemodynamics and replacement of the surrounding LDS with healthy tissue. We report our experience managing 24 especially difficult VUs with debridement and free flap coverage. PATIENTS AND METHODS: Between 1987 and 1997, 25 free flap procedures were performed in 22 patients for 24 recalcitrant VUs. Ulcers had been present for a mean of 5.24 years and had failed to heal with conservative therapy and split-thickness skin grafts (STSGs) (mean, 2.2). Eleven patients (46%) had exposed bone, tendon, or joint. At operation the area of LDS was excised, and all perforating veins were ablated. The defects after excision ranged from 100 to 600 cm(2) (mean, 237 cm(2)). The free flap was inset within the defect and covered with an STSG. RESULTS: We healed all 24 ulcers with free tissue transfer (one patient required a second flap after the first failed). There were no deaths. Local complications that required repeat STSG occurred in three (13%) of the 24 successful flap transfers. Four other flaps had minor local complications that healed with local wound care. Follow-up was available for 21 of the 24 successful flap transfers. No recurrent ulcers were identified in the territory of the flap after a mean of 58 months, but three patients had new ulcers in the same leg after 6 to 77 months. Patients with severe complications were hospitalized longer than those with minor or no complications (45.7 vs 12.8 days, P <.01), and their hospital charges were greater ($76,681 vs $30,428, P <.01). CONCLUSION: Free tissue transfer can provide rapid healing and long-term relief from severe VUs that are unable to be treated with conventional therapy. This technique improves venous hemodynamics, removes all liposclerotic tissue, provides an abundant blood supply, and resolves the tissue-related components of chronic ulceration. Although further work is needed to determine the optimal indications, this technique provides a durable treatment for especially recalcitrant ulcers.

Adolescent↗

PubMed1998

Expanded indications for the treatment of postcatheterization femoral pseudoaneurysms with ultrasound-guided compression.

BACKGROUND: The purpose of this study was to define the factors that predict successful ultrasound-guided compression repair (UGCR) of postcatheterization femoral pseudoaneurysms (PA) and to determine risks for recurrence, the most appropriate follow-up, and the optimal management of compression failures and recurrences. METHODS: A retrospective chart review was made. RESULTS: UGCR thrombosed 52 of 60 PA (87%). Predictors of compression failure were PA size of 8 cm and an associated arteriovenous fistula (AVF). AVF was the only predictor of recurrence. All seven recurrences (13%) were discovered on the first follow-up scan. Four were thrombosed with additional UGCR. Late rescanning after a mean of 264 days identified no recurrences. Four anticoagulated patients failed initial UGCR but were thrombosed in another session when their anticoagulation was briefly reversed. CONCLUSIONS: UGCR should be the initial management of PA because it is safe, effective, and durable. Temporary discontinuation of anticoagulation and multiple prolonged compression sessions may help treat recalcitrant cases. One follow-up scan is adequate for most patients. Recurrences should be initially treated with repeat UGCR.

Adult↗

PubMed1998

Prevention of ischemic damage using controlled limb reperfusion.

Following prolonged limb ischemia, a reperfusion injury may occur with the reintroduction of unmodified blood, resulting in tissue loss and, in severe cases, limb loss. We have shown that the reperfusion injury in the heart can be minimized by using controlled reperfusion with a substrate-enriched cardioplegia solution prior to restoring normal blood flow. This article describes two clinical cases in which we used controlled reperfusion in an ischemic limb to prevent limb loss. It demonstrates that a controlled, substrate-enhanced, hypocalcemic, leukodepleted, modified blood reperfusate solution can minimize limb reperfusion damage and improve functional recovery. This preliminary experience is presented to familiarize surgeons with this form of treatment and to describe the solutions and method of administration that can be used to avoid the devastating complications of severe limb ischemia.

Aged↗

PubMed1998

Omental transfer for salvage of the moribund lower extremity.

Use of omental flaps is well documented in soft tissue reconstruction of the head and neck, chest wall, and abdomen. Three cases of omental transfer for soft tissue reconstruction of the lower extremities are presented. In two patients, free vascularized omental flaps were used to cover deep soft tissue defects over the lower leg and in one patient, a pedicle flap was used to cover a deep groin defect extending into the hip joint. In all patients, use of an omental graft allowed revascularization and subsequent wound healing with good cosmetic results.

Aged↗

PubMed1997

Iliac reconstruction with arterial allograft during pancreas-kidney transplantation.

An intraoperative dissection of the external iliac artery during pancreas transplantation was successfully repaired using the donor iliac artery allograft as a conduit between the internal iliac and distal external iliac artery. An angiogram performed 6 months after surgery showed a patent bypass without stricture or pseudoaneurysm. At 1 yr follow-up after transplant the grafts are functioning well, and the affected extremity is normal. In immunosuppressed recipients of solid organ transplants, fresh arterial allografts may be successfully used for iliac artery reconstruction. Further study will be needed to determine the role of arterial allografts for lower extremity bypass surgery in immunosuppressed patients.

Adult↗

PubMed1996

Results of endoluminal grafting in an experimental aortic aneurysm model.

We studied the impact of an endoluminally placed stented aortic graft on the geometry of a surgically created abdominal aortic dilation (AAD) in nonatherosclerotic mongrel dogs. Patulous iliac vein patch infrarenal aortoplasty produced a fusiform AAD, doubling the aorta diameter. Lumbar and mesenteric aortic tributaries were preserved and no mural thrombus formed. AADs created in 23 dogs were endoluminally excluded through transfemoral placement of a thin-wall Dacron graft 4 +/- 2 months later. Balloon-expandable stents were used to anchor each end of the graft to the aorta. The graft was crimped radially in its body and longitudinally at its ends to provide longitudinal and radial expandability in these respective zones. Serial color duplex, angiography, and direct caliper measurements were made. Before graft placement, a 19% +/- 11% diameter growth was observed. At graft placement, flow arrest immediately occurred in the space between the graft and the AAD intima in all cases. Although microscopic recanalization of the thrombus in this space was seen at sacrifice 6 and 12 months later, no macroscopic duplex flow was imaged. A 10% +/- 11% reduction in AAD diameter was measured at 6 months (p < 0.001), with no further reduction at 12 months. Graft dimensions remained stable. No anastomotic leaks developed. AAD growth stopped during the first year after effective endoluminal exclusion in normotensive dogs despite patent side branches (< 1.5 mm internal diameter) and no mural thrombus at the time of graft placement. Whether microscopic recanalization of the thrombus that forms outside the graft has an impact after 1 year remains to be seen.

Animals↗

PubMed1994

A comparison of operative approaches and parameters predictive of success in multilevel arterial occlusive disease.

BACKGROUND: The correction of abnormal inflow alone in patients with multilevel arterial occlusive disease (MLAOD) may be inadequate to relieve limb-threatening ischemia. This study was undertaken to compare operative approaches and attempt to define preoperative parameters predictive of limb salvage in patients with MLAOD. STUDY DESIGN: The outcome after revascularization for 194 patients with limb-threatening ischemia MLAOD was assessed retrospectively. One hundred fifty-one patients initially underwent an inflow operation alone. Based on whether or not these patients required an outflow operation within one year, they were divided into two groups: group 1, no outflow operation (121 patients, 121 limbs), and group 2, outflow operation required for continued ischemic symptoms (30 patients, 30 limbs). A separate group of forty-three patients (43 limbs) underwent synchronous inflow-outflow operations, or multilevel revascularization, as their initial operative procedure (group 3). RESULTS: Perioperative complications and mortality rates did not differ between groups. Limb salvage rates were similar for groups 1 and 3, whereas in group 2, limb salvage rates were significantly reduced (p = 0.0184). Long-term limb salvage after an isolated inflow procedure was associated with lack of prior vascular reconstructions (p = 0.0002), the absence of tissue loss (p = 0.0019), and an infrageniculate angiographic runoff score of less than 6 (p = 0.054). CONCLUSIONS: In patients with limb-threatening MLAOD, synchronous inflow-outflow operations can be performed with resultant morbidity and mortality rates comparable with inflow alone. After an inflow operation, the approach of "expectant management" may ultimately compromise limb salvage if a subsequent outflow operation is required.

Adult↗

PubMed1993

Fetal haemoglobin levels in adult type 1 (insulin-dependent) diabetic patients.

Glycated haemoglobin levels (HbA1 and HbA1c) are established parameters of long-term glycaemic control in diabetic patients. Depending on the method used, fetal haemoglobin interferes with the assays for glycated haemoglobin. If present in high amounts, fetal haemoglobin may lead to overestimation of glycated haemoglobin levels, and therefore, of average blood glucose concentration in diabetic patients. Glycated (HbA1c) and fetal haemoglobin levels were measured by high pressure liquid chromatography in 60 (30 female) adult Type 1 (insulin-dependent) diabetic patients of Swiss descent, and were compared with levels obtained from 60 normal, non-diabetic control subjects matched for age and sex. Fetal haemoglobin levels were significantly higher in the diabetic patients (0.6 +/- 0.1%, mean +/- SEM; range: 0-3.6%) than in the control subjects (0.4 +/- 0.1%, p < 0.001). Elevated fetal haemoglobin levels (> or = 0.6%) were found in 23 of 60 diabetic patients (38%) compared to 9 of 60 control subjects (15%; chi 2 = 8.35, p < 0.01). In addition, fetal haemoglobin levels in diabetic patients are weakly correlated with glycated haemoglobin (HbA1c) (r = 0.38, p < 0.01). Fetal haemoglobin results were confirmed with the alkali denaturation procedure, and by immunocytochemistry using a polyclonal rabbit anti-fetal haemoglobin antibody. A significant proportion of adult patients with Type 1 diabetes has elevated fetal haemoglobin levels. In certain patients this may lead to a substantial over-estimation of glycated haemoglobin levels, and consequently of estimated, average blood glucose levels. The reason for this increased prevalence of elevated fetal haemoglobin remains unclear, but it may be associated with poor glycaemic control.

Adolescent↗

PubMed1993

Aspirin response and failure in cerebral infarction.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the biological effect of aspirin as measured by the inhibition of platelet aggregation in patients taking aspirin for stroke prevention and in patients with acute stroke. METHODS: We administered increasing doses of aspirin (325, 650, 975, and 1,300 mg daily) to 113 patients for stroke prevention and measured the inhibition of platelet aggregation in these patients and in 33 patients with acute stroke taking aspirin before stroke onset. RESULTS: Eighty-five patients on < or = 325 and six on > or = 650 mg aspirin had complete inhibition of platelet aggregation. Increase of the dose by 325 mg in nine of the 22 patients with partial inhibition of platelet aggregation produced complete inhibition in five patients at 650 mg and in one at 975 mg. At 1,300 mg, three patients still had only partial inhibition of platelet aggregation (aspirin resistance). Of the 33 inpatients with acute stroke, 24 had platelet aggregation studies done before further administration of aspirin. Of these, 19 had complete inhibition of platelet aggregation and three had partial inhibition, with production of complete inhibition of platelet aggregation at dose escalation; one patient was aspirin-resistant and the other noncompliant. CONCLUSIONS: How the inhibition of platelet aggregation relates to stroke prevention remains unclear. The ability of aspirin and the dose required to inhibit platelet aggregation may depend upon the individual.

Aged↗

PubMed1992

Acute ischemic proctitis. Report of six cases.

Acute ischemic proctitis is a rare clinical entity caused by vascular insufficiency of the major or collateral circulation to the rectum. It usually occurs following aortic or aortoiliac operations. Six patients with acute ischemic proctitis are presented; four cases occurred after direct arterial interruption, one after accidental embolization of the blood supply to the rectum, and one from tumor edema. Bloody diarrhea was the most common symptom. Loss of anal sphincter tone was also an early sign in three patients. The diagnosis of ischemia was made by mucosal appearance on proctosigmoidoscopy and is differentiated from infectious proctitis by stool culture. Superficial mucosal ischemia was treated without surgery, but deeper levels of necrosis required laparotomy and Hartmann's resection. Rectal excision was not necessary. Four patients survived the ischemic event.

Acute Disease↗

PubMed1992

Long-term results of venous reconstruction after vascular trauma in civilian practice.

The natural history of venous reconstruction (VR) in terms of patency and clinical outcome after vascular trauma has not been well documented. This study consists of 32 patients who had VR performed for extremity vascular trauma and were available for long-term assessment (mean follow-up time 49 months, range 6 to 108 months). The types of repair performed were as follows: lateral venorrhaphy (simple repair) (56%), interposition grafting (22%), patch repair (12.5%), and end-to-end repair (9.5%). Seventeen patients underwent venography after the operation with documentation of repair patency in eight patients (46%) and thrombosis in nine (54%). Only two patients had significant clinical edema at follow-up examination. Noninvasive venous evaluation consisted of Doppler ultrasonography, impedance plethysmography, photoplethysmography, and color-flow duplex scanning (CFDS). The photoplethysmography-derived venous refilling time of the injured extremity was 34.9 +/- 16.2 seconds whereas that of the contralateral noninjured extremity was 36.8 +/- 16.1 seconds (p = 0.5). Based on standard criteria for CFDS, 90% of VRs were patent. Eight repairs that were patent in the early postoperative period remained patent on CFDS. Of the nine repairs with early thrombosis, eight were assessed as patent on follow-up CFDS. In conclusion, VR is a durable surgical procedure associated with minimal morbidity, good long-term patency, and preservation of venous competence. The natural history of thrombosed VRs appears to be one of thrombus absorption with recanalization.

Adolescent↗

PubMed1991

A nine-year experience with crossover femoro-femoro-popliteal sequential bypass.

Multisegmental arterial occlusive disease may require a combined inflow and outflow procedure for optimal treatment of limb ischemia. Twenty-one patients with unilateral iliac artery stenosis or occlusion and ipsilateral superficial femoral artery occlusion underwent crossover femoro-femoro-popliteal sequential bypass during a 9-year period. Seventeen operations were for limb salvage. Patency rates were determined separately for each segment of the bypass. Primary patency rates for the femoro-femoral segment were 89%, 83%, and 57% at 1, 2, and 5 years, respectively. Primary patency rates for the femoro-popliteal segments were 68%, 62%, and 40% at 1, 2, and 5 years, respectively. Limb salvage rates were 100%, 90%, and 77% at 1, 2, and 5 years, respectively. This experience indicates that femoro-femoro-popliteal bypass is an effective treatment in selected patients with severe ischemia due to combined iliac artery and superficial femoral artery disease.

Aged↗

PubMed1991

Autogenous vein graft repair of injured extremity arteries: early and late results with 134 consecutive patients.

Autogenous vein tissue is recognized as the preferred material for extremity revascularizations that require the use of a conduit. However, the results after vascular repair of injured extremity arteries with autogenous vein interposition or bypass grafts have not been well defined. This study was done to determine both the early and late patency and limb salvage rates as well as the graft infection rate of autogenous vein repairs of injured extremity arteries. The records of 134 consecutive patients with acute extremity arterial injuries requiring repair with a reversed autogenous vein graft over a recent 5-year period were reviewed. Follow-up graft patency was defined by the presence of a palpable pulse and an extremity Doppler-derived pressure index of greater than or equal to 0.9 distal to the arterial repair. Cumulative patency was assessed by the life-table method. Acute graft thrombosis occurred in two patients, one of whom underwent successful graft thrombectomy. Four patients (3%) required extremity amputation: one patient with a thrombosed vein graft and three patients with patent vein grafts but nonsalvageable limbs as a result of myonecrosis (2) or osteomyelitis (1). No perioperative graft infections occurred. One hundred twenty-eight patients (97%) had an intact extremity and a patent vein graft at the time of hospital discharge. One hundred three patients (80%) were examined at 30 days, and all grafts were patent. Seventy-three patients (57%) were available for follow-up at intervals exceeding 6 months, and 40 patients (31%) were followed-up for periods exceeding 24 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

The natural history of intimal flaps in a canine model.

The natural history of arterial intimal flaps has not been well defined. This study characterizes the natural history of unrepaired intimal flaps. Thirty-nine 1-, 2-, and 3-mm hemispheric, distally based intimal flaps were made in 4- to 5-mm diameter canine femoral and carotid arteries. Twenty arteries had 2- and 3-mm intimal flaps and were monitored for short-term arterial thrombosis and flap extension. Nineteen had 1- and 2-mm intimal flaps and were monitored for thrombosis, long-term development of neointimal hyperplasia, arterial stenosis, and persistence of the flap. While 40% of the arteries with 3-mm intimal flaps developed thrombosis in 3 to 5 days, only 3% of the arteries with 1- or 2-mm intimal flaps developed thrombosis. Most 1- to 2-mm intimal flaps resolved and the subsequent development of neointimal hyperplasia or arterial stenosis was minimal. Arteries with hemodynamically significant stenoses from intimal flaps warrant repair, while arteries with smaller intimal flaps may not require repair.

Animals↗

PubMed1990

A rapid, accurate, noninvasive technique for diagnosing critical and subcritical stenoses in aortoiliac arteries.

Accurate hemodynamic evaluation of the aortoiliac system for the purpose of determining the need for an inflow procedure currently requires invasive pressure measurements. This study was undertaken to evaluate a noninvasive technique with the aortofemoral transfer function. Twenty-eight human aortoiliac segments were studied with intraarterial pressure measurements, with and without papaverine injection, and by calculation of the Doppler-derived mean power frequency index obtained by digital signal processing of aortic and femoral spectra. The procedure is menu driven and can be performed by any duplex ultrasound technologist. This technique involves recording 20 aortic and 20 femoral Doppler signals, requiring less than 1 minute of data acquisition time. Intraarterial pressure measurements were used to classify arteries into the three following groups: (1) normal arteries, (2) arteries with subcritical stenoses, and (3) arteries with critical stenoses. The mean power frequency index of group 1 arteries (n = 7) was 0.63 +/- 0.04, of group 2 arteries (n = 6) was 0.46 +/- 0.02, and of group 3 arteries (n = 15) was 0.21 +/- 0.05. These mean power frequency index values were significantly different by analysis of variance (ANOVA) (p less than 0.0001). Each group could be differentiated from the other groups with a sensitivity of 0.83 to 1.00, a specificity of 1.00, and an accuracy of 0.92 to 1.00 compared to intraarterial pressure measurements, including papaverine testing. Measurement of the mean power frequency index is a rapid, noninvasive technique that diagnoses and quantifies aortoiliac stenoses with an accuracy similar to intraarterial pressure measurements.

Aortic Diseases↗

PubMed1989

The role of isolated profundaplasty for the treatment of rest pain.

This study was undertaken to determine the efficacy and durability of profundaplasty and define preoperative factors predictive of success. The hospital charts, vascular laboratory data, and arteriograms of 20 patients having 21 isolated profundaplasties for ischemic rest pain between 1979 and 1987 were reviewed. Follow-up extended to 72 months (mean, 26 months). Early success was achieved in 12 extremities (57%) and life-table analysis showed continued success to six years in 11 extremities (55%). Of the multiple preoperative factors assessed, only a low-thigh/ankle gradient pressure index (TAGI) of less than 0.55 was predictive of success. Life-table analysis for limbs with a TAGI of less than 0.55 showed an 89% success rate at six years compared with only a 32% success rate for limbs with a TAGI of more than 0.55. Isolated profundaplasty for the treatment of ischemic rest pain can be an efficacious and durable procedure when patients are selected based on objective hemodynamic measurements.

Arteries↗

PubMed1989

Open transmetatarsal amputation in the treatment of severe foot infections.

Severe forefoot infections may lead to limb loss, even if addressed aggressively. Infection or gangrene that compromises the plantar skin flap may preclude a standard transmetatarsal or midfoot amputation, thereby culminating in a below-knee amputation. We report a series of forefoot infections with loss of the distal plantar skin. Open or guillotine amputation at the mid-metatarsal level led to a high rate of healing and a durable stump, provided that the level of infection did not extend beyond the metatarsal heads. Wound closure was obtained by wound contracture alone or by use of partial-thickness skin grafting. Rehabilitation was dependable. The association of diabetes mellitus or gangrene did not adversely affect outcome. Open transmetatarsal amputation is a safe surgical option preferable to midfoot or below-knee amputation for the treatment of severe forefoot infection that does not extend proximally beyond the metatarsal heads.

Amputation, Surgical↗

PubMed1989

Hypercoagulable states and lower limb ischemia in young adults.

This study prospectively evaluates hypercoagulable states in patients under 51 years of age undergoing lower extremity revascularization for ischemia and assesses early outcome after operation. Twenty patients whose ages range from 23 to 50 years (mean 40.8 years) were identified prospectively who underwent lower extremity revascularization and evaluation of hypercoagulability. Fifteen patients were male (75%), 10 were black (50%), six had hypertension (30%), and four were diabetic (20%). All but two were cigarette smokers (90%). Seven aortoiliac procedures and 13 infrainguinal procedures were performed. Six patients had one or more abnormalities of regulatory proteins (protein S deficiency, four; protein C deficiency, three; presence of lupus-like anticoagulant, three; plasminogen deficiency, two). Eight of 17 patients in whom platelet aggregation profiles were obtained showed increased reactivity (47%). Only 4 of 17 patients (24%) were normal when tested for all parameters. Arterial or graft thrombosis developed in four of the 20 patients within 30 days after operation. Hypercoagulability was found in all four patients whose revascularizations failed. A high incidence of hypercoagulable states was found in patients under 51 years of age with lower limb ischemia requiring revascularization. Hypercoagulability may have contributed to early postoperative thrombosis of the vascular procedure.

Adult↗