Impact of monocytic cells on recovery of uncultivable bacteria from atherosclerotic lesions.

OBJECTIVE: Epidemiological evidence suggests that infections may contribute to atherogenesis. However, with the exception of Chlamydophila pneumoniae, cultivable bacteria have not been recovered from atherosclerotic lesions. Therefore, we aimed at developing an approach to recover uncultivable bacteria from atherectomy tissues. METHODS: We cultured homogenates from atherectomy specimens from seven nonseptic patients undergoing surgery for arterial obstruction either alone or together with THP-1 monocyte-like cells. We performed 16S rDNA analysis, biochemical tests, random amplification of polymorphic DNA PCR analysis, quantitative polymerase chain reaction (qPCR) and immunohistofluorescence to identify the cultivated bacteria. Wilcoxon signed-rank tests were used to determine whether THP-1 treatment yielded a higher number of isolates than did the untreated controls. RESULTS: We recovered more bacteria from cocultures of atherectomy specimens with THP-1 cells than atherectomy specimens cultured alone. On average, tissue homogenates incubated with THP-1 cells versus control yielded 124 vs. 22 colony-forming units, a median of 140 vs. 7, respectively (P = 0.02). We recovered 872 isolates of limited number of species, including Propionibacterium acnes, Staphylococcus epidermidis and Streptococcus infantis and the fastidious anaerobe Porphyromonas gingivalis, and confirmed its presence in tissue using double immunofluorescence imaging. qPCR demonstrated the presence of ≥3.5 × 10(3) P. gingivalis genomes per gram of atheromatous tissue. CONCLUSIONS: These results indicate that viable previously uncultivable bacterial species are present within atheromas. Our results suggest revisiting the hypothesis that infections may have a causative role in atherosclerotic inflammation and have implications for research regarding novel diagnostics and treatments for cardiovascular disease.

Recombinant tissue-type plasminogen activator in the treatment of acute renal artery thrombosis after kidney transplantation.

Acute arterial thrombosis is an uncommon but potentially devastating consequence of kidney transplantation. Early recognition followed by thrombectomy may salvage the graft. We present a case of acute renal artery thrombosis after a living-related kidney transplant with successful treatment with operative thrombectomy and intraarterial infusion of recombinant tissue-type plasminogen activator.

Regulation of human mononuclear phagocyte migration by cell surface-binding proteins for advanced glycation end products.

Nonenzymatic glycation of proteins occurs at an accelerated rate in diabetes and can lead to the formation of advanced glycation end products of proteins (AGEs), which bind to mononuclear phagocytes (MPs) and induce chemotaxis. We have isolated two cell surface-associated binding proteins that mediate the interaction of AGEs with bovine endothelial cells. One of these proteins is a new member of the immunoglobulin superfamily of receptors (termed receptor for AGEs or RAGE); and the second is a lactoferrin-like polypeptide (LF-L). Using monospecific antibodies to these two AGE-binding proteins, we detected immunoreactive material on Western blots of detergent extracts from human MPs. Radioligand-binding studies demonstrated that antibody to the binding proteins blocked 125I-AGE-albumin binding and endocytosis by MPs. Chemotaxis of human MPs induced by soluble AGE-albumin was prevented in a dose-dependent manner by intact antibodies raised to the AGE-binding proteins, F(ab')2 fragments of these antibodies and by soluble RAGE. When MP migration in response to N-formyl-Met-Leu-Phe was studied in a chemotaxis chamber with AGE-albumin adsorbed to the upper surface of the chamber membrane, movement of MPs to the lower compartment was decreased because of interaction of the glycated proteins with RAGE and LF-L on the cell surface. The capacity of AGEs to attract and retain MPs was shown by implanting polytetrafluoroethylene (PTFE) mesh impregnated with AGE-albumin into rats: within 4 d a florid mononuclear cell infiltrate was evident in contrast to the lack of a significant cellular response to PTFE with adsorbed native albumin. These data indicate that RAGE and LF-L have a central role in the interaction of AGEs with human mononuclear cells and that AGEs can serve as a nidus to attract MPs in vivo.

Restoration of the cAMP second messenger pathway enhances cardiac preservation for transplantation in a heterotopic rat model.

Current organ preservation strategies subject graft vasculature to severe hypoxia (PO2 approximately 20 Torr), potentially compromising vascular function and limiting successful transplantation. Previous work has shown that cAMP modulates endothelial cell (EC) antithrombogenicity, barrier function, and leukocyte/EC interactions, and that hypoxia suppresses EC cAMP levels. To explore the possible benefits of cAMP analogs/agonists in organ preservation, we used a rat heterotopic cardiac transplant model; dibutyryl cAMP added to preservation solutions was associated with a time- and dose-dependent increase in the duration of cold storage associated with successful graft function. Preservation was also enhanced by 8-bromo-cAMP, the Sp isomer of adenosine 3',5'monophosphorothioate, and types III (indolidan) and IV (rolipram) phosphodiesterase inhibitors. Neither butyrate alone nor 8-bromoadenosine were effective, and the cAMP-dependent protein kinase antagonist Rp isomer of adenosine 3',5'monophosphorothioate prevented preservation enhancement induced by 8-bromo-cAMP. Grafts stored with dibutyryl cAMP demonstrated a 5.5-fold increase in blood flow and a 3.2-fold decreased neutrophil infiltration after transplantation. To explore the role of cAMP in another cell type critical for vascular homeostasis, vascular smooth muscle cells were subjected to hypoxia, causing a time-dependent decline in cAMP levels. Although adenylate cyclase activity was unchanged, diminished oxygen tensions were associated with enhanced phosphodiesterase activity (59 and 30% increase in soluble types III and IV activity, respectively). These data suggest that hypoxia or graft ischemia disrupt vascular homeostasis, at least in part, by perturbing the cAMP second messenger pathway. Supplementation of this pathway provides a new approach for enhancing cardiac preservation, promoting myocardial function, and maintaining vascular homeostatic properties.

Hypoxic induction of interleukin-8 gene expression in human endothelial cells.

Because leukocyte-mediated tissue damage is an important component of the pathologic picture in ischemia/reperfusion, we have sought mechanisms by which PMNs are directed into hypoxic tissue. Incubation of human endothelial cells (ECs) in hypoxia, PO2 approximately 14-18 Torr, led to time-dependent release of IL-8 antigen into the conditioned medium; this was accompanied by increased chemotactic activity for PMNs, blocked by antibody to IL-8. Production of IL-8 by hypoxic ECs occurred concomitantly with both increased levels of IL-8 mRNA, based on polymerase chain reaction analysis, and increased IL-8 transcription, based on nuclear run-on assays. Northern analysis of mRNA from hypoxic ECs also demonstrated increased levels of mRNA for macrophage chemotactic protein-1, another member of the chemokine superfamily of proinflammatory cytokines. IL-8 gene induction was associated with the presence of increased binding activity in nuclear extracts from hypoxic ECs for the NF-kB site. Studies with human umbilical vein segments exposed to hypoxia also demonstrated increased elaboration of IL-8 antigen compared with normoxic controls. In mice exposed to hypoxia (PO2 approximately 30-40 Torr), there was increased pulmonary leukostasis, as evidenced by increased myeloperoxidase activity in tissue homogenates. In parallel, increased levels of transcripts for IP-10, a murine homologue in the chemokine family related to IL-8, were observed in hypoxic lung tissue. Taken together, these data suggest that hypoxia constitutes a stimulus for leukocyte chemotaxis and tissue leukostasis.

Selective lymphoid irradiation. V. Synergism with pretransplant thymectomy or thymic irradiation in cardiac transplantation in rats.

Selective lymphoid irradiation (SLI) using palladium-109-hematoporphyrin (Pd-H), given four days prior to transplantation, combined with two doses of antilymphocyte globulin (ALG) (10 mg, days -2 and -1), was evaluated as a method of induction of permanent heterotopic cardiac allograft survival in the highly histoincompatible rat strain combination of ACI (RT1(1))-to-Lewis (RT1a). Both Pd-H and ALG localize poorly in the thymus, so this study evaluated whether thymic irradiation (TI) or thymectomy (TX) of the adult recipient results in indefinite allograft survival. Immunosuppression with Pd-H or ALG alone gave a mean survival time (MST) of 6.7 +/- 0.6 days, but the combination of the two agents led to an MST of 17.6 +/- 3.4 days. When TI was combined with Pd-H and ALG, cardiac allograft survival was prolonged to 50.2 +/- 13.9 days, but TI alone showed an MST of 10.3 +/- 1.8 days. Permanent cardiac allograft survival (greater than 250 days) was achieved in all thymectomized recipients treated with the combination of Pd-H and a brief course of ALG. These animals also accepted second-set skin grafts and rejected third-party skin grafts following more than 150 days of ACI cardiac allograft survival. Thymic irradiation, although effective in acting synergistically with SLI and ALG, led to prolonged, but limited allograft survival, although thymectomy with SLI and ALG is synergistic in prolonging allograft survival permanently without chronic immunosuppression.

B cell ontogeny in rabbits. Immunofluoresecent localization of B cells in fetal and neonatal rabbits.

The mammalian equivalent of the Bursa of Fabricius, the organ responsible for B cell maturation in avian species, has not been identified despite anatomic and ablative studies which suggest that the gut-associated lymphoid tissues (GALT) subserve this function. By analogy to the Bursa, the mammalian organ directing B cell ontogeny should be the site where IgM-bearing cells (B cells) are first identifiable. In this study, fluorescein-tagged heavy chain specific antirabbit IgM is used to localize initial sites of B cell appearance in rabbit fetal and neonatal lymphoid tissues. IgM-bearing cells are found 2 days before birth in the thymus and 1 day before birth in GALT. Immunoglobulin-bearing cells in spleen, lymph node, and bone marrow are undetectable until after birth. B cells bearing the IgM marked precede the appearance of IgG-bearing cells by 1 to 4 days in all instances. Intraperitoneal implantation of Millipore chambers containing immature fetal thymic tissue into neonatal hosts reveals that in situ development of IgM cells takes place independent of host cell traffic. The results suggest that B cell ontogeny in mammals is more complex than in avian species and demonstrates probable involvement of the thymus in the maturational process.

Donor pretreatment: rat heart allograft survival and measurement of passenger leukocyte depletion with indium-111.

The present experiment was designed to study the relationship between rat heart allograft survival and passenger leukocyte depletion in donor-pretreated animals. Untreated Lewis rats served as recipients of cardiac allografts from treated Fischer rats. Passenger leukocyte depletion was assayed with indium-111 oxine-labeled leukocytes (predominantly lymphocytes) which were infused into donor rats 6 hr before treatment with cyclophosphamide, antilymphocyte globulin (ALG), sublethal total body irradiation, or in vitro perfusion-preservation of the isolated beating heart. In vivo pretreatment of the donor with cyclophosphamide resulted in a significant prolongation of heart allograft survival but effected no reduction in graft-labeled lymphocytes. In vitro perfusion-preservation of the donor heart, for 1 to 2 hr, led to a 50 to 60% reduction in graft-labeled lymphocytes but failed to significantly prolong the survival of the heart allografts. Both ALG and sublethal total body irradiation donor pretreatments resulted in significant prolongation of heart allograft survival and a 20 to 25% labeled passenger lymphocyte depletion. This study demonstrates that there is no direct correlation between allograft survival and the degree of mobile passenger lymphocyte depletion, suggesting that the efficacy of leukocytotoxic donor pretreatment methods may depend in part on alternative mechanisms.

Use of indium-111-labeled cells in measurement of cellular dynamics of experimental cardiac allograft rejection.

This study evaluates the kinetics and utility of infused indium-111-labeled cells in detecting rejection in ACI to Lewis rat heart allografts. Syngeneic leukocytes, lymph node lymphocytes, and platelets were isolated and labeled with indium-111 (111In) oxine, respectively, and were infused i.v. into Lewis rats carrying beating ACI or syngeneic hearts from post-transplant days 0 to 6. Recipients were imaged serially at 24 hr after infusion of labeled cells followed by excision of both native and transplanted hearts for direct isotope count. Labeled leukocytes accumulative progressively in the allograft with the scan becoming positive by post-transplant day 4. The ratio of allograft to native heart isotope counts rose from 1.25 on day 1 to 10.07 (P less than 0.0001) on day 7. The Lewis recipients infused with labeled lymphocytes showed a positive scan on days 6 and 7 whereas the allograft to native heart isotope count ratio rose from 0.97 on day 1 to 5.33 (P less than 0.001) on day 7. Recipients infused with 111In-labeled platelets showed a positive scan on days 5 to 7 and the allograft to native heart isotope count ratio rose sharply from 2.56 on day 4 to 16.98 (P less than 0.005) on day 7. Syngeneic heart grafts failed to demonstrate significant accumulation of any of the labeled cell population. These studies confirm the importance of nonlymphocytic cells in cellular rejection, evaluate the kinetics of graft invasion by the various cell types, and suggest that the techniques used afford a method for a safe and an early detection of allograft rejection.

Selective lymphoid irradiation. I. An approach to transplantation.

The kinetics, distribution, and radiobiologic effects of palladium (Pd)-109-hematoporphyrin were determined in the rat. In addition, we studied the effect on rat heart allograft survival of Pd-109-hematoporphyrin, with and without antilymphocyte serum (ALS). A single sublethal dose of Pd-109-hematoporphyrin (up to 36 muCi/kg) resulted in the following: predominant concentration in lymphoid tissue and proximal bone marrow, complete central and proximal bone marrow ablation with preservation of distal bone marrow, massive depletion of lymphocytes from lymph nodes and spleen, an 80% reduction in peripheral blood lymphocytes which was completed by the addition of ALS, full recovery of lymphoid tissue and blood cellularity within 60 days of administration of radionuclide, and a 100% animal survival rate. This method of selective lymphoid irradiation (SLI) prolongs indefinitely Fisher cardiac allografts in Lewis recipients and significantly prolongs cardiac allograft survival across major histocompatibility barries (ACI to Lewis or to Fisher). Specific tolerance to donor strains was demonstrated by the acceptance of Fisher skin by Lewis recipients carrying 150-day-old Fisher hearts. Third party (ACI) skin allografts were rapidly rejected by the same animals. Further studies of SLI in larger animals are required to determine the optimal safe dose of SLI in man.

Comparison of laser-assisted fibrinogen-bonded and sutured canine arteriovenous anastomoses.

The effect of laser-assisted fibrinogen bonding (LAFB) on the development of intimal hyperplasia was studied with stress-strain profiles and histologic evaluation of canine arteriovenous fistulas (AVFs). In 19 animals femoral AVFs were created with an 808 nm diode laser after topical application of fibrinogen mixed with indocyanine green dye; in the contralateral limb a sutured AVF was created. The animals were divided into three groups. Group 1 dogs (n = 6) were killed serially up to 4 weeks after surgery to examine the healing of the anastomoses created with LAFB. Group 2 dogs (n = 6) were killed 1 month after surgery, and the fresh specimens were strained axially to produce a stress-strain profile graph. Group 3 dogs (n = 7) were killed 7 months after surgery, and the AVFs were infused with formalin under pressure and histologically prepared to allow comparison of the ratio of maximum to minimum intimal hypertrophy. Fibrinogen used for LAFB was resorbed during the first month after operation without evidence of foreign body reaction or inflammation. Tensile break force was not significantly different in the laser-bonded group (4.6 +/- 2.4 pounds) and the sutured group (4.3 +/- 1.7 pounds). The modulus (tensile break force per square inch), a measure of elasticity, identified the laser-bonded AVF (149 +/- 44 pounds per square inch) to be less rigid than the sutured AVF (203 +/- 35 pounds per square inch) (p less than 0.05). No significant differences in the degree of intimal hyperplasia were noted in any area of the anastomoses. Use of LAFB neither accelerates nor prevents intimal hyperplasia in a canine AVF model.(ABSTRACT TRUNCATED AT 250 WORDS)

A preliminary study of dye-enhanced laser photosclerosis.

Laser ablation of veins after injection of wavelength-specific dyes to enhance and localize energy absorption could provide a useful adjunct to current treatment options. To enhance the absorption of diode laser energy at 808 nm, ear veins of 41 rabbits were infused with 2 to 3 ml of indocyanine green dye (maximum absorption, 805 nm) and exposed for 2 to 20 seconds. Animals were killed between 0 and 28 days after operation. Discrete time intervals of laser exposure exist during which various-sized vessels can be ablated without significant thermal injury to the overlying tissue. Small vessels (0.2 mm in diameter) blanch after 2 to 3 seconds of exposure, whereas medium-sized vessels (2 mm in diameter) require 8 to 10 seconds. Vessels can be ablated with a power density as low as 11.1 W/cm2. Specimens taken immediately after laser exposure show vessel wall thinning and a reirradiation effect, created as laser energy initially absorbed by dye is reemitted. By the seventh day after operation, a brisk inflammatory response and acanthosis of the overlying epidermal layer develop. The lumen is partially filled by thrombus with cellular invasion. By postoperative day 28, the epidermal thickening and inflammatory reaction have resolved; the vessel walls are fibrotic. The use of low-power, air-cooled diode lasers, in conjunction with wavelength-specific dyes, may provide a simple, viable, and cosmetically appealing alternative to the treatment of superficial varicosities of the extremities.

Canine choledochotomy closure with diode laser-activated fibrinogen solder.

BACKGROUND: An alternative to mechanical stapling or hand suturing is needed to permit laparoscopic common bile duct exploration. We evaluated the strength and healing characteristics of canine choledochotomies sealed with a fibrinogen solder and a diode laser. METHODS: After creation of a 0.5 cm longitudinal choledochotomy, the edges were coapted with forceps, and a fibrinogen solder mixed with indocyanine green dye was applied. The solder was sealed in place with an 810 nm diode laser (125 W/cm2). RESULTS: Immediate mean leakage pressure was 264 +/- 7 mm Hg compared with 83 +/- 66 mm Hg in suture controls. This increased to 364 +/- 115 mm Hg at 2 days and was more than 510 mm Hg at 7 days. On histologic examination rapid reabsorption of the solder with no signs of inflammation or stenosis was seen. No episodes of dehiscence or peritonitis occurred. CONCLUSIONS: Laser soldering provides a watertight choledochotomy closure with adequate immediate strength allowing a reliable, technically feasible common bile duct exploration via a laparoscopic approach.

Hepatobiliary complications of polyarteritis nodosa.

Although polyarteritis nodosa (PAN) may result in thrombosis or aneurysm formation in any organ in the body, hepatobiliary complications are unusual. We reviewed seven cases that demonstrated the diagnostic difficulties and therapeutic options available in the management of hepatobiliary PAN. No consistent sign that indicated the severity of hepatobiliary PAN could be identified. In cases of thrombotic PAN, acalculus cholecystitis usually could be diagnosed preoperatively. Early tissue diagnosis and aggressive intervention are required for appropriate patient treatment. If the diagnosis is unclear, a preoperative muscle or skin biopsy specimen is often helpful in establishing a tissue diagnosis of PAN, even if no obvious pathologic condition is evident. Patients who undergo celiotomy for acalculus cholecystitis or peritoneal signs of an unclear origin should have tissue specimens (gallbladder wall, liver, or omentum) submitted for pathologic study. Angiography may be diagnostic preoperatively or when results of biopsies are equivocal. In addition, early angiography can define the extent of visceral involvement and permit control by embolization of hemorrhage secondary to aneurysm rupture. Awareness of the possibilities of thrombotic, ischemic, or bleeding complications from PAN allows more aggressive and rapid management of abdominal complaints, especially in patients who are receiving immunosuppressant therapy.

Increased tumor establishment and growth after laparotomy vs laparoscopy in a murine model.

OBJECTIVE: To test our hypothesis that tumors would be more easily established and grow more aggressively after laparotomy than after laparoscopy. This hypothesis was based on studies that have demonstrated that surgery can suppress immune function and facilitate tumor growth and that have shown preservation of immune function after laparoscopic procedures. DESIGN: Double-blinded, randomized, control trial. SETTING: Research laboratory and animal care facility. ANIMALS: One hundred forty 5- to 6-week-old C3H/He female mice. INTERVENTIONS: Three experiments with three groups each: laparotomy, insufflation, and anesthesia controls. All animals received an intradermal inoculation of tumor cells in the dorsal skin. The anesthesia control cohort underwent no procedure. The laparotomy cohort underwent a midline laparotomy from the xiphoid process to the pubis, which was closed after 30 minutes. The insufflation cohort underwent peritoneal insufflation with carbon dioxide for 30 minutes. MAIN OUTCOME MEASURES: Tumor volume, tumor mass, and incidence of tumor establishment. RESULTS: In the first experiment, the tumor volumes of the anesthesia control and insufflation groups followed a similar pattern of plateau and regression. The tumor volumes of the laparotomy group followed a different pattern and were significantly larger than those of the control and insufflation groups on postoperative days 6 and 12 (P < .05 for all comparisons). In the second experiment, tumors in the laparotomy group were approximately three times larger than those of the control group (P < .01) and almost twice as large as insufflation group tumors (P < .01) by mass. In the third experiment, there was a significantly higher incidence of tumor establishment in the laparotomy group than in the insufflation (P < .04) or control (P < .01) groups. The incidence was not different between the control and insufflation groups. CONCLUSIONS: Tumors were more easily established and grew more aggressively after laparotomy than after insufflation. These results, coupled with those that demonstrate an immune advantage to laparoscopy over laparotomy, suggest that the difference in observed tumor growth may be related to immune function. While much work remains to be done, we believe these data provide evidence of a previously undemonstrated benefit of laparoscopic intervention.

Reconstruction of urinary and gastrointestinal tracts in total pelvic exenteration: experience at Columbia-Presbyterian Medical Center.

OBJECTIVES: To examine the effectiveness of and complications from total pelvic exenteration (TPE) with maintenance of urethral and anal sphincter function for locally invasive tumors of the pelvis. METHODS: A retrospective review of 4 patients who have undergone TPE with urethral and anal sphincter preservation at Columbia-Presbyterian Medical Center in the last 2 years was performed with attention to perioperative morbidity and mortality, disease-free status, and need for further operative procedures. RESULTS: Two patients had colorectal adenocarcinoma, 1 had squamous cell carcinoma of the cervix, and 1 had prostate sarcoma. All had urinary tract reconstruction with orthotopic neobladder creation, and 3 of 4 had primary low rectal anastomoses for gastrointestinal reconstruction. One patient underwent creation of a J rectal pouch. One of 4 patients had received radiation therapy for the disease prior to surgery. There was no operative or perioperative mortality. Two of 4 patients required reoperation, 1 in the immediate postoperative period for repair of a left ureteral stricture, and the other 13 months postoperatively for repair of a rectal-neobladder fistula. With a mean follow-up of 25 months (range, 21 to 43 months), 3 of 4 patients are alive and free of disease. All living patients are continent of urine and 2 of 3 are continent of stool. CONCLUSIONS: Our experience confirms that TPE can be effective in controlling a variety of locally advanced pelvic tumors and can be performed in conjunction with simultaneous genitourinary and gastrointestinal reconstruction with minimal morbidity.

Recent clinical experience with the vena cava filter.

In the past at our institution, insertion of the vena cava filter was recommended almost exclusively for recurrent pulmonary emboli in anticoagulated patients or in those with emboli and contraindications to anticoagulation. More recently, prophylaxis has become a frequent indication for patients with extensive deep vein thrombosis and contraindications to anticoagulation. Herein, we review a recent series of caval filter insertions to determine if increased utilization of this technique is justified in terms of morbidity and effectiveness. Twenty-one filters were inserted in 20 patients during a 1-year period. The operative mortality rate was 0 and satisfactory filter placement was achieved in 90 percent of patients. There were no documented instances of recurrent emboli or vena cava thrombosis. These data suggest that use of the filter is justified as prophylaxis for patients at high risk for an initial pulmonary embolus in a clinical setting where heparin therapy is not appropriate.

Congenital abdominal aortic aneurysm causing renovascular hypertension, cardiomyopathy, and death in a 19-day-old neonate.

A full-term baby girl who was sent home day of life 2 was admitted to the hospital on day of life 7 for respiratory distress and poor feeding. The child was found to be hypertensive and in heart failure. Further workup led to the diagnosis of a suprarenal abdominal aortic aneurysm, but the infant had deteriorated clinically with heart failure, modest renal failure, renovascular hypertension, and no operative cure. The child died on day of life 20. Early diagnosis and prompt surgical resection are essential to managing this rare and lethal condition.

Femorofemoral bypass for unilateral iliac artery occlusion in the presence of bilateral superficial femoral artery occlusions.

The femorofemoral bypass has become a popular technique of reconstruction for unilateral iliac artery occlusion because of low morbidity and excellent long-term patency. A "steal phenomenon" is infrequently seen, but even in relatively sedentary patients with limb-threatening ischemia femorofemoral grafting has been associated with severe donor limb ischemia in occasional instances. This report describes five high risk elderly patients who underwent femorofemoral bypass for limb-threatening ischemia due to unilateral iliac artery occlusion in association with bilateral superficial femoral artery occlusions. All patients underwent successful bypass as judged by relief of rest pain and healing of ulcerations. Despite a pre-operative resting donor limb mean ankle/brachial index of .45, there was no deterioration of donor limb perfusion when patients were followed for a mean of 15.6 months. It is concluded that femorofemoral bypass is the procedure of choice for limb salvage in poor risk patients with adequate donor limb inflow regardless of the degree of outflow occlusive disease.

The prognostic value of the noninvasive vascular laboratory in autologous vein bypasses of the lower extremities.

A retrospective study of 34 patients with 29 autologous vein femoropopliteal and 8 femorotibial bypasses was conducted, examining the correlation of angiographic runoff and non-invasive flow determinants as prognostic indicators of early graft occlusion of lower limb bypass grafts. The followup period was 3-27 months, with a mean of 5.8 months. Graft patency and improvement in presenting symptoms were unrelated to preoperative ankle systolic pressure indices. Preoperative and postoperative flow measurements were similar in patients with patent grafts (greater than 12 months) and in those with early graft occlusion (0-6 months, p greater than .05). Preoperative pressure indices did not correlate with calf vessel runoff (p. greater than 05). The data suggest: (1) the noninvasive flow studies are not reliable predictors of future graft patency, (2) vessel runoff is not a reliable predictor of limb flow, and (3) bypass procedures in the lower extremities should not be excluded on the basis of noninvasive flow studies when indicated by other clinical parameters.