The art of surgery

The Polittico della Misericordia (Piero della Francesca, 1444–1462; fresco; Museo Civico di Sansepolcro, Sansepolcro, Italy). The painting includes a self-portrait of the artist in which a thyroglossal cyst is evident. According to Vasari, Piero della Francesca was a calm and wise man, who lived for more than 80 years, supporting the diagnosis of a benign condition. Published online in Wiley Online Library (www.bjs.co.uk). DOI:  10.1002/bjs.11107 Piero della Francesca (1417–1492), an Italian artist of the Renaissance period, did not receive the credit he deserved during his lifetime. He painted several frescos in his home town of Sansepolcro, Italy, after the local government and monastery tried to make the town as attractive as possible, in support of a bid to Rome to be an Episcopal seat. Piero della Francesca painted the fresco Polittico della Misericordia for the altar of the Church of the Confraternita della Misericordia. One of those praying is a self-portrait of the artist. The painter's subjects are arranged symmetrically, which gives a feeling of action, based on careful mathematical and geometrical studies. The importance of Piero della Francesca in the history of art was discovered by English tourists in the mid-19th century, and above all by Austen Henry Layard (1817–1894), one of the most influential archaeologists of the 19th century. During World War II, the commander of the British soldiers received the order to bomb Sansepolcro, which was occupied by the German army. The commander was interested in archaeology and had visited Sansepolcro several times before the war. He therefore decided not to bomb Sansepolcro immediately to avoid destroying the fresco. A couple of weeks later the German soldiers left Sansepolcro, and so the frescos of Piero della Francesca were saved. Read more about the fascinating events surrounding this painting in an essay  online.

The art of surgery

, Published online in Wiley Online Library (www.bjs.co.uk). DOI: 10.1002/bjs.10863 In times when art usually depicted perfection, Caravaggio (1571-1610) painted everyday reality. He used people walking the streets of Rome to represent holy figures. Caravaggio loved many women. He killed a man in a duel and had to flee from Rome to avoid being 'beheaded by anybody who saw him'. In this biblical scene he painted, Judith Beheading Holofernes, Judith is a portrait of Fillide Melandroni, the reason for the duel. Holofernes is a self-portrait. Judith looks cruel, in mourning clothes, seeking revenge for the assassination of her lover. The maidservant, almost an evil spirit, has a voluminous thyroid goitre, and she seems to encourage the revenge of Fillide. Read more about Caravaggio and this painting in an essay online.

The study of art and its influence on the education of surgeons

A look back at some key figures in the crossover between the two disciplines.

Treatment of rectovaginal fistula after colorectal resection with endoscopic stenting: long-term results

AIM

To treat patients with rectovaginal fistula after anterior resection for cancer using self-expanding metal stents.

METHOD

Ten patients of mean age of 56.3 years with rectovaginal fistula after colorectal resection for cancer were treated with endoscopic placement of a self-expanding metal stent. In three patients a diverting proximal stoma had been performed elsewhere. The rectal opening of the fistula was located from 3 to 10 cm from the anal verge (mean 6 cm). All patients had preoperative radiotherapy. In seven patients the stent was placed as the initial treatment while three referred patients had had multiple failed operations.

RESULTS

There were no complications after the procedure. At a mean follow-up of 24 months the rectovaginal fistula has healed without major faecal incontinence in eight patients. In the remaining two the fistula has reduced significantly in size to allow a successful flap transposition.

CONCLUSION

Endoscopic placement of a self-expanding metal stent is a valid adjunct to treat patients with rectovaginal fistula after colorectal resection for cancer.

Statins reduce levels of metalloproteinases in patients with carotid occlusive disease

AIM

Pharmaceutical stabilization of an unstable low-grade carotid artery stenosis delays surgery and improve outcome. Statins can be used to reduce intimal media thickness. Our aim was to determine the clinical and biological effects of rosuvastatin on plaque stabilization or regression.

METHODS

Forty-two consecutive male patients presenting with an asymptomatic internal carotid artery plaque uniformly anechogenic (group 1) 40-50% lumen diameter reduction formed the basis of the study. A group of 35 patients affected with a uniformly echogenic carotid artery stenosis (40-50%) served as control (group 2). Patients were followed-up every 8-month for 2 years with B-mode ultrasonography and color imaging. A computed tomography angiography (CTA) was performed before the initiation of the study period and at the end to confirm plaque characteristics and the degree of stenosis. Ticlopidine (250 mg/day) and rosuvastatin (10 mg/day) were administered. One blood sample was drawn at every control to assess the release of matrix metallopoteinases (MMPs)-1, -2, -3, -9, tissue inhibitors of metalloproteinases (TIMPs)-1 and -2.

RESULTS

After the administration of rosuvastatin plasma level of MMP-1, -2, -3 and -9 significantly decreased in both groups (P<0.001). Conversely, plasma level of TIMP-1 and -2 significantly increased in both groups (P<0.001). B-mode ultrasonography and color imaging and CTA failed to demonstrate a stabilization or regression of uniformly anehogenic carotid plaque during follow-up.

CONCLUSION

Rosuvastatin decreases the plasma level of MMPs and increases those of TIMPs. However, neither progression nor stabilization of low-grade unstable carotid plaques was seen.

Self-expandable metal stents in the treatment of benign anastomotic stricture after rectal resection for cancer

AIM

To evaluate the use of self-expandable metallic stents to treat patients with symptomatic benign anastomotic stricture after colorectal resection.

METHOD

Ten patients with a benign symptomatic anastomotic stricture after colorectal resection were treated with endoscopic placement of a self-expandable metal stent.

RESULTS

The stent was placed successfully in all 10 patients without any major morbidity. At a mean follow-up of 18 months the stenosis was resolved successfully in 7 out 10 patients (70%). The remaining three patients were subsequently treated successfully with balloon dilatation.

CONCLUSION

Self-expandable metal stents represent a valid alternative to balloon dilatation to treat patients with benign symptomatic anastomotic stricture after colorectal resection for cancer.

Self-expanding metal stents for treatment of anastomotic complications after colorectal resection

Self-expanding metal stents (SEMS) can be used to treat patients with symptomatic anastomotic complications after colorectal resection. In the present case series, 16 patients with symptomatic anastomotic stricture after colorectal resection were treated with endoscopic placement of SEMS. Seven patients had a "simple" anastomotic stricture and nine patients had a fistula associated with the stricture. The anastomotic fistula healed without evidence of residual stricture or major fecal incontinence in seven of the nine patients. Overall the anastomotic stricture was resolved in 10 of the 16 patients. SEMS placement represents a valid adjunctive to treatment in patients with symptomatic anastomotic complications after colorectal resection for cancer.

Basic fibroblast growth factor mediates carotid plaque instability through metalloproteinase-2 and -9 expression

OBJECTIVE(S)

We hypothesized that basic fibroblast growth factor (bFGF) may exert a role in carotid plaque instability by regulating the expression of matrix metalloproteinases (MMP).

METHODS

Plaques obtained from 40 consecutive patients undergoing carotid endarterectomy were preoperatively classified as soft or hard. Serum bFGF was pre- and postoperatively measured. The release of MMP-2 and MMP-9 in the blood serum, and the activity, production and expression in the carotid specimens was analyzed. Specific anti-bFGF inhibition tests were performed in vitro on human umbilical artery smooth muscle cells (HUASMC) to evaluate the role of bFGF in the activity, production and expression of MMP-2 and -9.

RESULTS

Twenty-one (53%) patients had a soft carotid plaque and 19 (48%) a hard plaque. Preoperative bFGF serum levels were higher in patients with soft plaques [soft=34 (28-39) pg/mL and hard=20 (17-22) pg/mL-p<0.001] and postoperatively returned to normal values (when compared to 10 healthy volunteers). The serum levels of MMP-2 in patients' with soft plaques were higher than those in patients' with hard plaques [soft=1222 (1190-1252) ng/mL and hard=748 (656-793)ng/mL-p<0.0001]. MMP-9 serum values were 26 (22-29) ng/mL for soft plaques and 18 (15-21) ng/mL for hard plaques (p<0.0001). We found increased activity, production and expression of MMP-2 and -9 in soft plaques compared to hard plaques (p<0.001). In vitro inhibition tests on HUASMC showed the direct influence of bFGF on the activity, production and expression of MMP-2 and -9 (p<0.001).

CONCLUSIONS

bFGF seems to exert a key role in carotid plaque instability regulating the activity, production and expression of MMP thus altering the physiologic homeostasis of the carotid plaque.

Bimodal concentration-dependent effect of thrombin on endothelial cell proliferation and growth factor release in culture

BACKGROUND

The role of thrombin in the stimulation of endothelial cell (EC) proliferation is controversial. The aim of this study was to investigate if thrombin regulates cell proliferation and production of platelet-derived growth factor (PDGF), bovine fibroblast growth factor (bFGF), and transforming growth factor beta(1) (TGF-beta(1)) by bovine aortic ECs.

METHODS

ECs, obtained from thoracic aortas of calves, were stimulated with thrombin at various concentrations (from 0.05 to 1.0 IU/ml) in serum free culture. Mitogenic activity of thrombin on ECs was determined by tritiated thymidine uptake. The release of PDGF, bFGF, and TGF-beta(1) was assessed by ELISA. PDGF release was confirmed by Western blot and bFGF and TGF-beta(1) mRNA expression was determined by polymerase chain reaction (PCR).

RESULTS

Thrombin at high concentrations did not cause any increase in EC proliferation after 72 h of culture and induced inhibition of EC proliferation after 96 h and 8 days of culture. It induced a decrease in PDGF release and an increase in TGF-beta(1) release. Thrombin at low concentrations induced a significant increase in EC proliferation at 72 h, 96 h, and 8 days of culture. It induced an increase in PDGF release and a decrease in TGF-beta(1) release. bFGF release was higher than control at all thrombin concentrations. These data were confirmed by Western blot and PCR studies.

CONCLUSIONS

Thrombin regulates EC growth through the inhibition of EC proliferation at high concentrations and through the stimulation of EC proliferation at low physiological concentrations. EC proliferation is partially mediated by autocrine production of PDGF, bFGF, and TGF-beta(1).

Increased production of cytokines and growth factors by aortic allografts: A possible explanation for myointimal hyperplasia formation

Accelerated myointimal hyperplasia is a major complication of arterial allografts. The aim of our study was to analyze the role of growth factors in the genesis of myointimal hyperplasia in arterial allografts. Two groups of experiments were performed: Isografts and Allografts. The Isograft group consisted of 18 inbred Lewis rats in which a 1-cm long segment of aorta was inserted as abdominal aortic interposition graft. The aortic segments were obtained from syngeneic Lewis rats. The Allograft group consisted of 18 inbred Lewis rats, in which a 1-cm long segment of aorta was interposed at the level of the abdominal aorta. The aortic segments were obtained from allogeneic Brown-Norway rats. No immunosuppression was used. The animals were sacrificed 4 weeks after surgery and the aortic grafts were analyzed by light, electron microscopy (n = 3 for each group) and immunohistochemistry (n = 3 for each group). In addition, aortic segments (n = 12 for each group) were put in an organ culture to assess production of growth factors. All allografts showed evidence of severe myointimal hyperplasia, which was minimal in isografts. PDGF, bFGF and TGF-beta(1) production, generally considered to be the cause of myointimal hyperplasia, was not increased in allografts, whereas IL-1, TNF-alpha and GM-CSF production was increased in allografts and probably lymphocytes were the source of these cytokines (p < 0.001). We conclude that myointimal hyperplasia in aortic allografts is associated with an increase of IL-1, TNF-alpha and GM-CSF produced by lymphocytes.

Basic fibroblast growth factor and myointimal hyperplasia after experimental polytetrafluoroethylene arterial grafting

OBJECTIVE

To assess the role of polyclonal antibodies to basic fibroblast growth factor (bFGF) in inhibiting myointimal hyperplasia after insertion of polytetrafluoroethylene (PTFE) grafts in rats.

DESIGN

Experimental study.

SETTING

University laboratory, Italy.

ANIMALS

24 inbred Lewis rats.

INTERVENTIONS

A segment of PTFE I cm long was interposed in the abdominal aorta. The animals were randomised in two groups, n = 12 in each. The first were given polyclonal antibodies to bFGF at the time of operation, and for the first two postoperative days; and the second were given non-specific IgG at the same time periods.

MAIN OUTCOME AND MEASURES

Two animals died during the immediate postoperative period of anaesthetic complications. 12 animals (6 in each group) were killed 7 days postoperatively (24 hours after injection of 5-bromo-deoxyuridine BrdU) to assess smooth muscle cell proliferation. The remaining 10 animals (5 in each group) were killed after 1 month to assess the degree of anastomotic myointimal hyperplasia.

RESULTS

Antibodies to bFGF resulted in less smooth muscle cell proliferation at the anastomoses as well as anastomotic myointimal hyperplasia. Smooth muscle cell proliferation was reduced to about half in animals treated with anti-bFGF antibodies. Neointimal thickness was reduced in treated animals.

CONCLUSIONS

We conclude that after PTFE arterial grafting there is increased production of bFGF at the anastomotic regions that leads to smooth muscle cell proliferation and formation of myointimal hyperplasia. Agents that reduce the production of bFGF may also reduce the development of myointimal hyperplasia after PTFE arterial grafting.

Thrombin induces production of growth factors from aortic smooth muscle cells

BACKGROUND

Myointimal hyperplasia is a common complication of arterial recontructive surgery. The serine protease thrombin has a major role in vessel wall healing and eventual myointimal hyperplasia formation. The aim of this study was to determine the effect of thrombin on the production of PDGF AA and bFGF by arterial smooth muscle cells.

MATERIALS AND METHODS

Bovine smooth muscle cells were stimulated with thrombin in a serum-free culture. The release of PDGF AA and bFGF was assessed by ELISA. The effect of thrombin on the proliferation of confluent monolayers of bovine smooth muscle cells was determined by tritiated thymidine uptake.

RESULTS

Smooth muscle cells stimulated with thrombin released more PDGF AA (P < 0.001) and bFGF (P < 0.001) than the control. Addition of anti-PDGF AA and anti-bFGF antibodies to the medium of smooth muscle cell cultures neutralized the mitogenic effect of thrombin (P < 0.001).

CONCLUSIONS

The findings of our study suggest that thrombin may lead to myointimal hyperplasia formation through induction of PDGF and bFGF production by smooth muscle cells.

Suppression of smooth muscle cell proliferation after experimental PTFE arterial grafting: a role for polyclonal anti-basic fibroblast growth factor (bFGF) antibody

OBJECTIVES

To determine the role of polyclonal anti-basic Fibroblast Growth Factor (bFGF) antibody in inhibiting the proliferation of smooth muscle cells after experimental polytetrafluorethilene (PTFE) arterial grafting.

MATERIALS

In 14 male inbred Lewis rats (weight 250 mg) a 1 cm long segment of PTFE was interposed at the level of abdominal aorta. Animals were randomised to receive polyclonal anti-bFGF antibody (group A: n = seven animals) or aspecific immunoglobulin (group B: n = seven animals). Anti-bFGF antibody or aspecific immunoglublin were given intraperitoneally at the end of operation, and for the first 2 postoperative days. Animals were sacrificed 7 days after surgery, 24 h after intraperitoneal injection of BromodeoxyUridin (BrdU) to label proliferating smooth muscle cells.

RESULTS

One animal in each group died in the immediate postoperative period due to anaesthetic problems. All grafts were patent at the time of sacrifice. BrdU labelling index was statistically higher in the control group B animals at the level of the anastomotic regions (proximal anastomosis: group B 7.9% vs. group A 4.1%. Distal anastomosis: group B 5.1% vs. group A 2.6% p = 0.009) and at the level of PTFE graft (group B 3.8% vs. group A 2.6% p = 0.002), while there was no statistical difference between the control thoracic aorta of the two groups.

MAIN CONCLUSIONS

bFGF plays a major role in the proliferation of smooth muscle cells at the level of the anastomoses after arterial PTFE grafting. Agents able to block the action of bFGF may be useful in inhibiting the formation of myointimal hyperplasia.

Oxidised LDL (OxLDL) induces production of platelet derived growth factor AA (PDGF AA) from aortic smooth muscle cells

OBJECTIVES

Elevated concentrations of oxidised low density lipoproteins (OxLDL) are associated with accelerated atherogenesis. The aim of our study was to determine the effect of OxLDL on the proliferation rate and platelet derived growth factor (PDGF) AA production on aortic smooth muscle cells. High density lipoproteins (HDL), which are known to have a protective effect against atherosclerosis, were used as control.

MATERIALS AND METHODS

Bovine aortic smooth muscle cells were grown in presence of increased concentrations of OxLDL and HDL and in presence of control medium culture (DMEM). Proliferation rate was assessed by 3H-thymidine uptake. PDGF AA production was determined by ELISA and Western Blot Analysis.

RESULTS

OxLDL increased the proliferation rate of aortic smooth muscle cells as compared to DMEM and HDL (p < 0.001). The mitogenic activity of OxLDL on smooth muscle cells was reduced adding anti-PDGF AA antibodies (p < 0.001). PDGF AA production by aortic smooth muscle cells was increased after exposure to OxLDL as compared to DMEM (p < 0.001). HDL significantly reduced the production of PDGF AA by aortic smooth muscle cells (p < 0.001).

CONCLUSIONS

Part of the atherogenic effect of OxLDL is mediated through the autocrine production of PDGF AA from aortic smooth muscle cells.

Formation of myointimal hyperplasia and cytokine production in experimental vein grafts

BACKGROUND

The purpose of this study was to determine the correlation between progression and regression of myointimal hyperplasia (MH) and cytokine production in experimental vein grafts. Although the autologous vein is the best suitable bypass conduit for reconstruction of peripheral arteries, at the end of the first year thrombosis in the coronary and lower extremity circulation ranges from 20% to 50%. Many of these failures are caused by MH.

METHODS

In 76 inbred Lewis rats, a 1 cm long segment of inferior vena cava was inserted at the level of the abdominal aorta. The segments of inferior vena cava were obtained from syngeneic Lewis rats. In 56 animals the arterial vein graft was explanted 3 days (n = 10), 7 days (n = 10), 4 weeks (n = 26), and 12 weeks (n = 10) after operation. In 20 animals the vein graft was explanted 4 weeks after being in the arterial system and reimplanted as iliac venovenous bypass in syngeneic Lewis rats. These grafts were explanted 2 weeks (n = 10) and 8 weeks (n = 10) later. Grafts were analyzed by light and electron microscopy, morphometric study, and histochemical analysis and were put in an organ culture to assess cytokine production.

RESULTS

We observed MH formation in arterial vein grafts and MH regression in reimplanted vein grafts (p < 0.001). MH formation was correlated with production of platelet-derived growth factor, basic fibroblast growth factor, interleukin-1, and tumor necrosis factor-alpha. MH regression was correlated with transforming growth factor-beta 1 production.

CONCLUSIONS

On the basis of the results of our study, we conclude that MH formation in experimental vein grafts depends on production of platelet-derived growth factor, basic fibroblast growth factor, interleukin-1, and tumor necrosis factor-alpha, and MH regression depends on transforming growth factor-beta 1 production. Cytokine therapy may represent a valuable new treatment to prevent vein bypass failures caused by MH.

Shear stress induces transforming growth factor-beta 1 release by arterial endothelial cells

BACKGROUND

Myointimal hyperplasia is a common complication after vascular reconstruction. Increasing shear stress has been shown to reduce formation of myointimal hyperplasia. The aims of our study were (1) to analyze the correlation between shear stress and release of transforming growth factor (TGF)-beta 1 by endothelial cells and (2) to determine the effect of TGF-beta 1 on smooth muscle cell proliferation.

METHODS

Bovine arterial endothelial cells were subjected to increasing shear stress in an in vitro serum-free system. The release of TGF-beta 1 by endothelial cells was assessed by enzyme-linked immunosorbent assay and Western blot analysis. The effect of TGF-beta 1 on the proliferation of the subconfluent monolayer of bovine smooth muscle cells was determined by tritiated thymidine uptake.

RESULTS

Shear stress induced a significant increase of the release of TGF-beta 1 by endothelial cells (p < 0.001). This phenomenon was proportional to the level of shear stress. The amount of TGF-beta 1 released by endothelial cells subjected to shear stress had a significant inhibitory effect on growth rate and tritiated thymidine uptake of smooth muscle cells.

CONCLUSIONS

On the basis of the results of our study, we conclude that increasing shear stress induces release of TGF-beta 1 by arterial endothelial cells in a concentration that has a clear inhibitory effect on smooth muscle cell proliferation. This phenomenon could explain the inhibitory effect of increasing shear stress on the formation of myointimal hyperplasia.

Fluid shear stress increases the release of platelet derived growth factor BB (PDGF BB) by aortic endothelial cells

OBJECTIVES

The aim of this study was to determine the correlation between shear stress and the release of Platelet Derived Growth Factor (PDGF BB) by aortic endothelial cells.

DESIGN AND SETTING

Laboratory in vitro study.

MATERIALS

Bovine aortic endothelial cells were seeded in fibronectin-coated cylinders at 1.0 x 10(6) cells/tube and allowed to reach confluence and to adhere for 48 hours. The experimental groups were subjected to nonpulsatile, laminar flow of 50, 100, 150 ml/min in polystyrene cylinders (i.d. 10 mm) of a closed circulatory loop giving a shear stress on the endothelial cells of 3, 6, 9 dyn/cm2. The control group was subjected to similar incubation conditions without flow.

OUTCOME MEASURES

The release of PDGF BB by endothelial cells was measured by ELISA and Western Blot Analysis.

RESULTS

Shear stress increased significantly (p < 0.01) the release of PDGF BB by endothelial cells.

CONCLUSIONS

PDGF BB release by endothelial cells may be one of the mechanisms linking hemodynamic forces and adaptation of blood vessels wall.

Growth factors and myointimal hyperplasia in experimental aortic allografts

OBJECTIVES

To analyse the role of growth factors (platelet derived growth factor, PDGF; basic fibroblast growth factor, bFGF; interleukin 1, IL-1) in the genesis of myointimal hyperplasia in arterial allografts.

MATERIALS

Two groups of experiments were performed: isografts and allografts. The isograft group consisted of 15 inbred Lewis rats in which a 1 cm long segment of aorta was inserted as an abdominal aortic interposition graft. The aortic segments were obtained from syngenic Lewis rats. The allograft group consisted of 15 inbred Lewis rats, in which a 1 cm long segment of aorta was interposed at the abdominal aorta level. The aortic segments were obtained from allogenic Brown-Norway rats.

CHIEF OUTCOME MEASURES

The animals were killed 4 weeks after surgery and were analysed by morphometric analysis (n = 3 for each group). In addition, production of PDGF, bFGF and IL-1 by aortic segments (n = 12 for each group) in organ culture was assessed.

MAIN RESULTS

Allografts had more myointimal hyperplasia, than isografts (p < 0.05). PDGF and bFGF production, generally considered to be the cause of myointimal hyperplasia, was not increased in allografts. IL-1 production was higher in allografts (p < 0.001).

MAIN CONCLUSIONS

Myointimal hyperplasia in aortic allografts is dependent on growth factors produced by the graft itself. These growth factors are different from PDGF and bFGF that generally have been implicated in the genesis of naturally occurring myointimal hyperplasia and atherosclerosis. IL-1 may have a principal role in the genesis of myointimal hyperplasia in arterial allografts.

Hemodynamic forces modulate simultaneously the release of growth factors and the organisation of cytoskeleton of aortic smooth muscle-cells

Recurrent stenosis because of myointimal hyperplasia or atherosclerosis after carotid endarterectomy occurs in 5-15% of the cases. The key event is the abnormal proliferation of arterial Smooth Muscle Cells (SMC). After endarterectomy SMC are directly exposed to the blood flowing under pressure. The aim of the present study was to determine the changes in morphology, cytoskeleton organisation, and release of growth factors by SMC exposed to laminar flow. Subconfluent SMC were exposed to a level of shear stress of 6 dyne/cm2 (100 ml/min) for 24 hours under conditions of steady laminar flow. The changes in morphology and cytoskeleton organisation were analysed by light and scanning electron microscopy, and by fluorescence microscopy. Growth factors release was assessed by ELISA. After exposure to laminar flow, SMC assumed a spindle-like shape; they lost many of their protrusions and there was a clear reorganisation of the cytoskeleton and simultaneously their released a higher quantity of PDGF and bFGF. In this study, we found simultaneous changes in cytoskeleton organisation and release of growth factors in SMC exposed to flow. Cytoskeleton reorganisation might be the mechanism through which SMC respond to changes in blood flow. These findings may help to explain the genesis of myointimal hyperplasia following carotid endarterectomy.

Growth factor production by arterial and vein grafts: relevance to coronary artery bypass grafting

BACKGROUND

Occlusion caused by myointimal hyperplasia, atherosclerosis, or both is the main reason for late failure of saphenous vein coronary artery bypass grafts. On the other hand, internal mammary artery grafts are usually spared from atherosclerosis. Evidence exists that platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) are involved in the genesis of myointimal hyperplasia and atherosclerosis. The aim of this study was to assess the production of PDGF and bFGF by arterial and vein grafts.

METHODS

In 20 inbred Lewis rats alpha 1 cm long segment of arterial graft was interposed at the level of the abdominal aorta. In a control group of 20 Lewis rats alpha 1 cm long segment of vein graft was implanted at the level of the abdominal aorta. Animals were killed 4 weeks after operation, and the grafts were studied in serum-free organ culture to assess the production of PDGF and bFGF. RESULTS. Arterial grafts produced a smaller quantity of PDGF and bFGF than vein grafts (p < 0.01) Higher mitogenic activity was present in the conditioned media from vein grafts than in the conditioned media from arterial grafts (p < 0.001). A large amount of myointimal hyperplasia was present in all vein grafts.

CONCLUSIONS

This phenomenon could explain the rarity of atherosclerotic changes in internal mammary coronary bypass grafts.

Progression and regression of myointimal hyperplasia in experimental vein grafts depends on platelet-derived growth factor and basic fibroblastic growth factor production

PURPOSE

The factors that lead to myointimal hyperplasia (MH) in arterial vein grafts (AVGs) are unknown. Platelet-derived growth factor (PDGF) and basic fibroblastic growth factor (bFGF) are two powerful mitogens for smooth muscle cells that have been implicated in the genesis of MH. The aim of this study was to analyze the correlation between progression and regression of MH and production of PDGF and bFGF in experimental vein grafts.

MATERIALS

In 64 inbred Lewis rats, a 1-cm segment of inferior vena cava was inserted at the level of the abdominal aorta. The segments of inferior vena cava were obtained from syngenic rats. In 48 rats, the AVG was explanted 3 days (n = 8), 7 days (n = 8), 4 weeks (n = 24), and 12 weeks (n = 8) after surgery. In 16 rats the vein graft was explanted after being in the arterial system for 4 weeks and was reimplanted as a venous-venous bypass in syngenic Lewis rats. Reimplanted vein grafts (RVGs) were explanted 2 weeks (n = 8) and 8 weeks (n = 8) later. Grafts were analyzed by light and electron microscopy, morphometry, and histochemistry, and were put in organ culture to assess PDGF and bFGF production and mitogenic activity.

RESULTS

We observed MH formation in AVGs and MH regression in RVGs (p < 0.001).PDGF and bFGF production correlated with the degree of MH (p < 0.01). Histochemistry showed PDGF and bFGF in the area of MH in AVG, which disappeared in RVG. Conditioned media from AVG had greater mitogenic activity than RVG or control veins.

CONCLUSION

MH formation and regression in experimental vein grafts correlate with PDGF and bFGF production.

Growth factor production after polytetrafluoroethylene and vein arterial grafting: an experimental study

PURPOSE

Occlusion caused by myointimal hyperplasia appears to be the main reason of late failure of polytetrafluoroethylene (PTFE) arterial bypass grafts. Evidence exists that growth factors are involved in the genesis of myointimal hyperplasia. The aim of this study was to assess the release of platelet-derived growth factor (PDGF) and basic fibroblastic growth factor (bFGF) by PTFE arterial grafts.

METHODS

In 15 inbred Lewis rats a 1 cm long segment of PTFE was interposed at the level of the abdominal aorta. In a control of another 15 Lewis rats in a vein graft was implanted at the level of the abdominal aorta. Animals were killed four weeks after implantation and the tissue was studied in organ culture for release of PDGF AA, PDGF BB, and bFGF.

RESULTS

PTFE grafts released a greater quantity of PDGF AA than did control vein grafts (28 +/- 4 ng/cm2/72 hr vs 7 +/- 2 ng/cm2/72 hr). Similarly, PTFE grafts released a greater quantity of bFGF than did arterial vein grafts (308 +/- 22 ng/cm(2)/72hr vs 204 +/- 20 ng/cm2/72 hr).

CONCLUSIONS

We conclude that PTFE arterial grafts released a high quantity of growth factor, which could explain, in part, the occurrence of distal anastomotic myointimal hyperplasia.

The degree of porosity influences the release of growth factors by healing polytetrafluoroethylene (PTFE) grafts

OBJECTIVES

The aim of this study was to determine the influence of the degree of porosity on the release of growth factors (PDGF AA, PDGF BB, bFGF) by healing PTFE grafts.

DESIGN AND SETTING

Laboratory animal study.

MATERIALS

1 cm long segments of non-reinforced PTFE grafts (30 microns fibril length, 2 mm internal diameter, 0.39 mm thick) were placed as an abdominal aortic interposition in Lewis rats. Fifteen grafts served as control (Group A; porous grafts); in eight rats (Group B; non porous grafts) the PTFE graft was completely wrapped by a non-porous plastic envelope. Animals were killed 4 weeks after surgery.

OUTCOME MEASURES

The release of PDGF AA, PDGF BB and bFGF was assessed by Enzyme Linked Immunosorbent Assay (ELISA).

RESULTS

The release of PDGF AA, PDGF BB and bFGF was statistically higher in porous grafts. The only histological difference between the two groups was that porous PTFE grafts were invaded by many tufts of capillaries from the surrounding tissue, whereas this phenomenon was absent in non porous PTFE grafts.

CONCLUSIONS

The degree of porosity influences the release of growth factors by healing PTFE grafts. This fact may have implication in the endothelisation of PTFE grafts and in myointimal hyperplasia formation as well.

bFGF release is dependent on flow conditions in experimental vein grafts

OBJECTIVES

Basic Fibroblastic Growth Factor (bFGF) is a powerful mitogen for smooth muscle cells and has been implicated in the genesis of Myointimal hyperplasia. The aim of this study was to determine the release of bFGF by veins in different haemodynamic conditions.

DESIGN AND SETTING

Laboratory animal study.

MATERIALS

In 39 Lewis rats, a 1 cm long segment of inferior vena cava was inserted at the level of the abdominal aorta. The segments of inferior vena cava were obtained from syngenic Lewis rats. Arterial Vein Grafts (AVG) were harvested after 4 weeks (AVG 4) and 12 weeks (AVG 12). In 16 animals the arterial vein grafts were explanted 4 weeks after the initial operation and reimplanted (Reimplanted Vein Grafts: RVG) in syngenic Lewis rats as venous-venous bypass grafts at the level of the left iliac vein and harvested after 2 weeks (RVG 2) and 8 weeks (AVG 8).

OUTCOME MEASURES

The tissue was studied in organ culture in a serum-free system for (1) release of bFGF (immunoassay) and (2) mitogenic activity of the conditioned media. Scanning electron and light microscopy studies were also performed.

RESULTS

bFGF release by veins increased significantly (p < 0.01) when veins were inserted in the arterial circulation, and decreased significantly (p < 0.01) when grafts were reimplanted in the venous system. bFGF release (ng/cm2): [Formula: see text]

CONCLUSION

Vein inserted in the arterial circulation release a higher quantity of bFGF. This could explain in part, the formation of myointimal hyperplasia in arterial vein graft.

Seasonal variation in the incidence of ruptured abdominal aortic aneurysm

In order to determine any possible influence of climatic variables on the incidence of abdominal aortic aneurysm rupture, we reviewed 49,144 autopsies performed in two major hospitals in Rome, Italy, from January 1956 to March 1986. There were 297 subjects who were found to be sufferers of atherosclerotic abdominal aortic aneurysm for a prevalence of 0.6%. The aneurysm was intact in 220 cases (74%) and ruptured in 77 cases (26%). The highest incidence of ruptured aneurysm occurred during the Autumn and in the months May and July. The incidence of ruptured aneurysm was highest in case of significant changes of the atmospheric temperature. There was no correlation between the incidence of ruptured aneurysm and barometric pressure or humidity.

Shear stress induces changes in the morphology and cytoskeleton organisation of arterial endothelial cells

OBJECTIVES

The aim of this study was to determine the changes in the morphology and cytoskeleton organisation of endothelial cells (EC) determined by exposure to a laminar flow. Cultured EC were exposed to a wall shear stress of 6 dyne/cm2 for 24 hours.

CHIEF OUTCOME MEASURES

The morphology of EC was analysed by light and scanning electron microscopy. The organisation of the cytoskeleton was determined by double fluorescence labeling with antibody anti-vimentin, anti-vinculin, anti-tubulin, and with rhodamine-labeled phalloidin.

RESULTS

EC exposed to laminar flow become round-shaped with decreased area of adhesion to the substrate. There was a clear reorganisation of the cytoskeleton after exposure to shear stress; the distribution of actin changed from a stress fibre pattern to a more diffuse membrane-associated distribution. These changes in shape and cytoskeleton organisation were reversible after a 48-hour resting period.

CONCLUSIONS

EC respond to laminar flow in a predictable manner and these findings may be correlated to the functional changes of EC observed after exposure to shear stress.

Shear stress influences the release of platelet derived growth factor and basic fibroblast growth factor by arterial smooth muscle cells. Winner of the ESVS prize for best experimental paper 1993

OBJECTIVES

To determine the correlation between haemodynamic forces and the release of two mitogens for smooth muscle cells (SMC): Platelet Derived Growth Factor (PDGF) and basic Fibroblast Growth Factor (bFGF).

METHODOLOGY

Bovine aortic smooth muscle cells were seeded on fibronectin coated polystyrene cylinders and allowed to reach confluence. The cells were subjected to a laminar flow of 50 cc/min (3 dyne/cm2), 100 cc/min (6 dyne/cm2) and 150 cc/min (9 dyne/cm2) in an in vitro system. Control cells were subjected to similar incubation conditions without flow.

PRINCIPAL RESULTS

Shear stress increased the release of mitogens by SMC. The release of mitogens was proportional to the level of shear stress and was still evident 24 hours after flow cessation. Conditioned serum-free medium from SMC subjected to shear stress increased tritiated thymidine uptake in Swiss 3T3 fibroblasts 13-fold as compared to conditioned serum-free medium from control SMC not subjected to shear stress (p < 0.01) and threefold as compared to standard control (p < 0.001). Addition of an excess of anti-PDGF antibody reduced the mitogenic activity of the conditioned medium by 30% (p < 0.01). Addition of an excess of anti-bFGF antibody reduced the mitogenic activity of the conditioned medium by 60% (p < 0.01).

CONCLUSIONS

Increasing shear stress promotes the release of both PDGF and bFGF from arterial SMC in culture and is a possible explanation for atherosclerosis formation.

Shear stress increases the release of interleukin-1 and interleukin-6 by aortic endothelial cells

BACKGROUND

The aim of this study was to determine the correlation between shear stress and the release of interleukin-1 (IL-1) and interleukin-6 (IL-6) by endothelial cells (EC).

METHODS

Bovine aortic EC were seeded in fibronectin-coated cylinders at 1.0 x 10(6) cells/tube and allowed to reach confluence and to adhere for 48 hours. The experimental groups were subjected to a laminar flow of 100 ml/min (6 dyne/cm2). The control group was subjected to similar incubation conditions without flow. The release of IL-1 and IL-6 by EC was measured by enzyme-linked immunosorbent assay.

RESULTS

Shear stress increased significantly (p < 0.01) the release of IL-1 and IL-6 by EC. The release of these two cytokines had different kinetics.

CONCLUSIONS

Increasing shear stress facilitates release of IL-1 and IL-6 by EC. Previous reports have shown that IL-1 and IL-6 promote vascular smooth-muscle cell proliferation. Thus abnormal flow conditions with increasing shear stress may predispose to smooth-muscle cell proliferation that characterizes early atherosclerotic plaque development by an interleukin-mediated mechanism.

Shear stress modulates the proliferation rate, protein synthesis, and mitogenic activity of arterial smooth muscle cells

BACKGROUND

The aim of this study was to determine the correlation between hemodynamic forces and proliferation of smooth muscle cells (SMC).

METHODS

Bovine arterial SMC were seeded in a fibronectin-coated polystyrene cylinder at 5 x 10(5) cells/tube and allowed to reach confluence and to adhere for 48 hours. The experimental groups were subjected to a laminar flow of 150 ml/min (9 dyne/cm2), 100 ml/min (6 dyne/cm2), and 50 ml/min (3 dyne/cm2) for 24 hours. The control group was subjected to similar incubation conditions without flow. The cells in the experiments remained attached and viable. All experiments were performed in triplicate or more.

RESULTS

Shear stress significantly reduced (p < 0.001) the 24-hour incorporation of tritiated thymidine and cell proliferation. This effect was proportional to the level of shear stress and was still evident 24 hours after flow cessation. Results of flow cytometry confirmed a lower percentage of SMC in S phase with increasing shear stress. Synthesis of cell-associated proteins was increased twofold (p < 0.01) in SMC subjected to laminar flow. SMC subjected to shear stress released a higher quantity of mitogens, including a platelet-derived growth factor (PDGF)-like substance as detected by immunologic testing. Fifty percent volume per volume conditioned serum-free medium from SMC subjected to shear stress increased threefold the tritiated thymidine uptake in PDGF receptor-bearing Swiss 3T3 cells as compared with conditioned serum-free medium from control SMC not subjected to shear stress and twelvefold as compared with standard control. The release of mitogens was proportional to the level of shear stress and was still evident 24 hours after flow cessation. The mitogenic activity was partially reduced (30%, p < 0.01) by an excess of monospecific anti-PDGF antibody.

CONCLUSIONS

We conclude that (1) increasing shear stress inhibits SMC proliferation and stimulates the synthesis of cell-associated proteins and the release of mitogens and (2) decreasing shear stress facilitates proliferation of SMC. Thus, in situations of arterial flow separation, the increased release of mitogens from SMC subjected to high shear stress and the increased proliferation rate and susceptibility to mitogens of SMC subjected to very low shear stress may generate a critical condition that predisposes to the development of atherosclerosis with early plaque formation in regions of low-flow shear stress.

Growth factor release by smooth muscle cells is dependent on haemodynamic factors

Abnormal proliferation of smooth muscle cells (SMCs) is a key event in the development of the atherosclerotic plaque. The early atherosclerotic plaque localises preferentially in areas of flow separation. The basic mechanisms which correlate haemodynamic forces and atherosclerotic plaque formation are not known. Bovine arterial SMCs were subjected to increasing levels of shear stress for 24 h in an in vitro system. The control group was subjected to similar incubation conditions without flow. SMCs subjected to shear stress released a higher quantity of mitogens, including a platelet derived growth factor (PDGF)-like substance. This mitogenic activity was partially reduced (30%, p < 0.01) by an excess of monospecific anti-PDGF antibody. The release of mitogens was proportional to the level of shear stress and was still evident 24 h after flow cessation. In conclusion, shear stress influences the release of mitogens; this might represent a mechanism which links haemodynamic forces and atherosclerotic plaque formation.

Response of arterial smooth muscle cells to laminar flow

This study was designed to determine whether laminar flow influences the proliferation rate and morphology of smooth muscle cells (SMC) in culture. Bovine aortic SMC were subjected to a shear stress of 6 dyne/cm2. The control group was subjected to similar incubation conditions without flow. Flow cytometry demonstrated decreased proliferation rate in SMC subjected to laminar flow. This phenomenon was still evident 24 hours after flow cessation. SMC were examined by light and electron microscopy. SMC subjected to laminar flow aligned along the direction of flow assuming a spheric morphology. These changes were reversible after a 48-hour resting period. The degree of organization of actin, tubulin and other microfilaments was evaluated by indirect immunofluorescence. SMC subjected to shear stress showed a clear reorganization of the cytoskeleton with expression of stress fibres. These changes were reversible after a 48-hour resting period. These findings may contribute to understanding the mechanisms by which SMC in vivo respond to forces generated by blood flowing under pressure.

Endothelial cell seeding after carotid endarterectomy in a canine model reduces platelet uptake

Post-endarterectomy platelet deposition may play an important role not only in vessel wall healing, but also in the development of progressive stenosis. Using a canine model, we investigated the effect of endothelial cell seeding on platelet deposition on endarterectomised arteries. Thirteen dogs underwent bilateral carotid intimectomy (5 cm long) and one side was seeded with an average of 2 x 10(6) viable freshly harvested endothelial cells. Blood flow was restored 20 min after seeding. On the contralateral side, a sham-seeding was performed. Deposition of 111indium-labelled autologous platelets was studied with sequential gamma camera images 3-5 h, 1, 2, 3, 4 days and 4 weeks after surgery. Platelet uptake was statistically reduced on the seeded side. Animals were killed at 4 weeks (nine dogs) and 5 weeks (four dogs) after surgery. Seven arteries for each group were found to be occluded. We conclude that endothelial cell seeding on endarterectomised arteries is feasible and reduces platelet uptake. Improvement in the efficiency of seeding and reduction of endothelial cell loss might permit clinical application of this technique.

Healing of high-porosity polytetrafluoroethylene arterial grafts is influenced by the nature of the surrounding tissue

The aim of this study was to determine the influence of the nature of the perigraft tissue in the healing pattern of high-porosity polytetrafluoroethylene (PTFE) vascular grafts. Nine-centimeter long segments of unreinforced experimental high-porosity (60 microns) PTFE grafts were placed as abdominal aortic interposition in mongrel dogs. Three grafts served as controls (group A); in five dogs (group B) a 25 x 25 cm piece of devascularized omentum was wrapped around the graft. In five dogs (group C) the omentum with its own vascular supply was completely wrapped around the graft. Animals were killed 4 weeks after surgery. The percentage of thrombus-free area was 31% in group A grafts, 39% in group B grafts, and 79% in group C grafts (p less than 0.01). Scanning electron microscopy showed many confluent areas of endothelium-like cells in the midportion of group C grafts, corresponding to capillary ingrowth. Transmural endothelial migration was more evident in group C grafts. We conclude that the nature of the perigraft tissue influences transmural capillary migration and the endothelialization rate of high-porosity PTFE grafts in dogs. Agents able to increase capillary formation in the perigraft tissue might improve endothelialization of vascular grafts.

Modulation of arterial smooth muscle cell growth by haemodynamic forces

To define the correlation between flow dynamics and the proliferation of arterial smooth muscle cells (SMCs), bovine arterial SMC were subjected to increasing laminar flow shear stress in an in vitro system. Smooth muscle cells were seeded in a fibronectin-coated polystyrene cylinder at 5 x 10(5) cells/tube. The experimental groups were subjected to increasing shear stress (3, 6, 9 dyn cm-2) for a 24-h period. The control group was subjected to similar incubation conditions without flow. Shear stress reduced significantly (p less than 0.01) the 24-h incorporation of tritiated thymidine and cell proliferation. This effect was proportional to the level of shear stress and was still evident 24 h after flow cessation. Flow cytometry demonstrated a lower percentage of SMCs in S-phase with increasing shear stress. Extrapolation of these findings to the clinical setting might explain how unphysiological shear stress can predispose to the abnormal proliferation rate of SMCs and early plaque formation.

Importance of ulceration of carotid plaque in determining symptoms of cerebral ischemia

In order to investigate the relationship between carotid plaque morphology and symptoms of cerebral ischemia, a prospective clinicopathological study was performed. Ninety consecutive intact carotid plaques obtained from surgery and 43 carotid plaques from cadavers without symptoms of cerebral ischemia were evaluated. Ulceration and mural thrombus were the only morphologic findings statistically correlated to the presence of hemispheric symptoms (p less than 0.02). Intramural hemorrhage was more common in patients with hemispheric symptoms but this difference was not statistically significant (p = 0.31). Plaque causing high degree stenosis had a higher incidence of intramural hemorrhage (p = 0.04) and ulceration (p less than 0.02). Ulceration of plaque plays a major role in the onset of hemispheric symptoms. The results of our study support the hypothesis that in the majority of the cases, hemispheric symptoms are embolic in nature.

Sealed rupture of abdominal aortic aneurysms

Sealed rupture of abdominal aortic aneurysms, even if uncommon, deserves particular attention for the possibility of misdiagnosis and for the deleterious effects of such a misdiagnosis. Sixteen patients (mean age 72 years; range 65 to 84 years) with chronic sealed rupture of abdominal aortic aneurysms are reported. Two patients had acute rupture of the aneurysm, and at operation chronic contained rupture was found along with the recent hemorrhage. One patient died after surgery. The remaining patients underwent successful resection with long-term survival and regression of symptoms. Consideration of sealed abdominal aortic aneurysm rupture should be included when examining elderly patients with history of unexplained back pain or femoral neuropathy. Computed tomography is a useful aid in the diagnosis of sealed rupture. Ultrasonography is less accurate; in three patients ultrasonography failed to diagnose the presence of the rupture.

Comparison of two techniques to isolate microvascular endothelial cells from the omentum

The purpose of the study was to compare two different techniques for isolation of omental microvascular endothelial cells (ECs). Segments of unreinforced polytetrafluorethylene (PTFE) grafts, 9 cm long and 6 mm in diameter, were implanted in 22 dogs as an aortic interposition. Fourteen grafts were seeded with a mean of 7 x 10(5) viable ECs, derived from the microvessels of the omentum: eight grafts (group A) were seeded with ECs obtained by collagenase digestion and by filtration through a pore mesh; six grafts (group B) were seeded with ECs obtained by collagenase digestion and by Percoll gradient separation. In eight grafts (group C), the ECs were not added to the preclot mixture and served as a control. Animals were sacrificed 5 weeks after surgery. The percentage of thrombus-free area was 65 +/- 22% for group A grafts and 74 +/- 15% for group B grafts (NS). The subendothelial layer was 280 +/- 60 microns thick in group A and 220 +/- 30 microns thick in group B (P less than 0.05). Seeded grafts showed a higher production of 6-keto-PGF1 alpha after addition of sodium arachidonate than control grafts. Percoll gradient separation allows isolation of a more purified suspension of ECs. Refinements in omental EC procurement are still required to minimize contamination with other types of cells.

Subclavian artery revascularization: a comparison between carotid-subclavian artery bypass and subclavian-carotid transposition

Extrathoracic revascularization has become the most popular form of surgical treatment of symptomatic subclavian disease. Despite the many theoretical advantages, subclavian-carotid transposition (SCT) has not gained wide popularity. During a 15-year period, 46 patients underwent carotid-subclavian bypass (CSB) or SCT for symptoms referable to occlusion of the subclavian artery. Follow-up ranged from 2 to 148 months (mean, 46.9 months). Seven-year actuarial patency rate was 100% for SCT and 86% +/- 7% for CSB (p = NS). Mean operative time and intraoperative blood loss were significantly reduced for SCT (p less than 0.05). After CSB a continuous deterioration of the hemodynamic status of the reconstruction was noted, whereas there were no significant changes after SCT (p less than 0.05). Whenever feasible, SCT should be considered the operation of choice for patients with symptomatic severe subclavian artery disease.

Operative strategies in patients with symptomatic internal carotid artery occlusion

A 15-year experience with 98 patients who underwent extracranial artery reconstruction for symptomatic internal carotid artery occlusion is reviewed. Thromboendarterectomy of the occluded carotid artery resulted in unacceptably high mortality and morbidity rates, and long-term patency of the internal carotid artery was rarely achieved. Carotid endarterectomy on the side opposite the occlusion proved to be successful in relieving nonlateralizing symptoms of cerebral ischemia, whereas results were less encouraging in patients with focal symptoms in the hemisphere ipsilateral to the occlusion. External carotid artery reconstruction on the side of the occlusion was successful in relieving focal symptoms. Surgical treatment in patients with symptomatic internal carotid artery occlusion should be planned in each patient on the basis of symptoms and anatomic pattern.

Inflammatory aneurysms of the abdominal aorta: incidence, pathologic, and etiologic considerations

Among 486 patients undergoing repair for abdominal aortic aneurysm (AAA) during a 12-year period, 30 (6.2%) had evidence of "inflammatory" AAA. One patient (3%) had acute rupture, and six patients (20%) had chronic contained rupture. Ureteral obstruction was evident in 20% of the patients. In the early period of the study there were two postoperative deaths and operative time and blood loss were significantly increased. In the last period of the study, no attempt was made to separate the duodenum and the ureters from the aneurysm; there was no operative mortality, and operative time and blood loss were similar to that of patients with atherosclerotic aneurysms. In 23 of 100 specimens of atherosclerotic AAA, microscopic findings resembling inflammatory AAA were found. On the basis of our study we conclude the following: (1) Inflammatory AAAs are simply atherosclerotic aneurysms that show an unusual accentuation of the chronic inflammation observed in relation to atherosclerotic aneurysms. (2) Operative technique should be modified to avoid excessive dissection and lysis of ureters and duodenum. (3) Excellent early and late results can be expected with proper surgical technique. (4) The causes of AAA are multiple, and chronic contained rupture of the aneurysm and reactive lymphatic hyperplasia might play a role of greater significance than previously thought.

Extrathoracic and transthoracic management of vascular disease of the aortic arch branches: a 16-year experience

To determine factors influencing results of operation for proximal brachiocephalic arterial disease, a 16-year review of 74 consecutive patients was undertaken. A total of 62 subclavian, 14 common carotid, 6 innominate, and 2 vertebral arteries were revascularized during 79 procedures. The approach was transthoracic in 12 operations and extrathoracic in 67. Mean follow-up was 57 +/- 45 months. Two patients (2.5%) died of stroke after extrathoracic revascularization of the common carotid artery. Cumulative 5-year and 10-year freedom from neurological events was 81% and 75%, respectively. The best results were obtained with transthoracic procedures, with revascularization of the subclavian artery rather than the common carotid artery, and in operations performed in patients without associated distal carotid disease. In view of the recent progress in operative techniques and postoperative surgical care, the choice between the transthoracic approach and the extrathoracic approach should not be biased; rather, they should remain equal and viable alternatives based on anatomical and clinical features of the individual patients.

Natural history of recurrent carotid artery disease

Controversy exists as to whether early and late recurrent stenosis of the carotid artery represents two distinct types of recurrence or whether it is the same type of lesion detected at different times. Eleven specimens from patients whose carotid arteries were reoperated upon were examined. A temporal sequence was noted: with increasing intervals, the relative presence of areas of myointimal hyperplasia tended to decrease, whereas the relative presence of features of atherosclerosis tended to increase. The clinical data and B-mode ultrasound studies performed from one to 190 months after 210 carotid endarterectomies were reviewed. Twenty-seven carotid arteries (12.9 per cent) exhibited hemodynamically significant restenosis. Three ultrasonographic patterns were described: homogenous soft plaque, homogenous hard plaque and heterogenous plaque. A previous correlation between ultrasonographic and pathologic findings showed the three ultrasound patterns to correlate with myointimal hyperplasia, fibrous atherosclerotic plaque and complex atherosclerotic plaque, respectively. Soft plaques were detected earlier than heterogenous plaques (p less than 0.001). Results from serial studies showed progression of soft plaque to hard or heterogenous plaque, or both. Early and late recurrent lesions are the same type of lesion detected at different intervals. Symptoms of cerebral ischemia are more common at the stage of heterogenous plaque (p = 0.02).

Identification of abdominal aortic aneurysm patients with different clinical features and clinical outcomes

To determine the clinical characteristics and factors influencing outcome in patients with atherosclerotic abdominal aortic aneurysms (AAA), 526 patients who underwent aneurysmal resection were retrospectively reviewed: Group I had clinical evidence of atherosclerotic occlusive disease; Group II had no evidence of atherosclerotic occlusive disease. The incidence of ruptured AAA, multiple aneurysms, and a family history of AAA was higher in Group II patients. We concluded that patients with AAA and without atherosclerotic occlusive disease in other areas represent a subgroup with peculiar clinical characteristics. In planning operative treatment and during the follow-up period, it should be kept in mind that Group II patients have a higher incidence of aneurysm rupture; the incidence of late pseudoaneurysm is higher; and there is a greater possibility of aneurysm in other arterial segments. It remains to be seen if the pathogenetic mechanism of AAA formation in Group II patients is different from that in Group I patients.

Combined aortofemoral and extended deep femoral artery reconstruction. Functional results and predictors of need for distal bypass

In patients with combined aortoiliac and femoropopliteal occlusive disease, severe involvement of the deep femoral artery (DFA) has often been considered an indication for simultaneous aortofemoral and femorodistal bypass grafting. In 73 patients (87 limbs) with multilevel disease, extended DFA reconstruction was performed with aortofemoral bypass. Five-year actuarial patency of the reconstructions and overall five-year actuarial limb salvage were 62.2% and 60.2%, respectively. Of 20 variables tested, four were significantly associated with the functional outcome of the procedures. Multivariate analysis identified two factors as predictive of outcome independently from other variables: preoperative ankle-brachial pressure index and angiographic status of the below-knee popliteal artery. However, in case of reoperation for occluded aortofemoral graft, these factors lost their validity. Extended DFA reconstruction is a valuable and durable procedure able to provide an adequate outflow and distal perfusion. Careful judgment in each clinical situation will aid in selecting a small group of patients in which simultaneous femorodistal bypass is required.