Occlusion of the celiac trunk, the inferior mesenteric artery and stenosis of the superior mesenteric artery in peripheral thrombangiitis obliterans

Buerger's disease is an inflammatory occlusive disease which commonly involves medium-sized or smaller vessels of extremities. Mesenteric involvement in Buerger's disease is very rare. It can occur at any time during the course of the disease and presents with acute mesenteric ischaemia. In this study, a case of Buerger's disease with mesenteric involvement diagnosed before the onset of acute mesenteric ischaemia and managed endovascularly is reported.

Surgical repair of a giant renal artery aneurysm: a case report

A case of a giant renal artery aneurysm and multiple small branch aneurysms in a 48-year old man is presented. The largest aneurysm was repaired successfully with kidney preservation. Small branch aneurysms were left alone. Subsequent CT scans 6, 12 and 20 months after the operation revealed the same aneurysms without any increase in size and shape.

A late onset carotido-jugular fistula following shotgun injury

The incidence of arteriovenous fistulae (AVF) is quite rare in the head and neck region comprising less than 4% of all the traumatic AVF encountered elsewhere in the body. A 42-year-old man presented with a palpable thrill in the cervical region and headache. He had a shotgun injury 10 years ago and had no problem until the previous three months. Diagnosis of a high output traumatic AVF between right common carotid artery and internal jugular vein was made arteriographically. Presence of a neighbouring traumatic aneurysm on the common carotid artery and 9 mm diameter of the fistula tractus suggested open surgery. At the operation ligation of the tractus and aneurysmorraphy was performed and the patient was discharged in the third postoperative day. He has still no problem. This case documented that a shotgun injury even 10 years later may result with an AVF.

Role of tumour necrosis factor in lung injury caused by intestinal ischaemia–perfusion

Background

Despite the well known inflammatory effects of tumour necrosis factor (TNF), the mechanism of TNF-mediated lung injury following ischaemia–reperfusion (IR) is still unclear. In this study, the role of TNF in the development of acute lung injury following intestinal IR was investigated.

Methods

Male Wistar rats underwent either sham operation (n = 10) or 1 h of superior mesenteric artery occlusion and 2 h of reperfusion (IR; n = 10) or pretreatment with anti-TNF polyclonal antibody 2 mg kg−1 and IR (n = 6). Lung injury was evaluated by Evans blue dye concentration, immunohistochemical staining and morphometric analysis. Intestinal injury was assessed by Evans blue dye concentration and histological examination.

Results

Intestinal IR resulted in lung injury characterized by an increase in Evans blue dye concentration, polymorphonuclear neutrophil (PMN) sequestration, and obvious staining for expression of pulmonary CD11b and CD18. Pretreatment of animals with anti-TNF antibodies led to a reduction in the sequestration of PMNs (P < 0·05), a decrease in expression of pulmonary intercellular adhesion molecule 1 and CD18 (P < 0·01), and a diminished histological grade compared with the IR-only group. Anti-TNF antibody pretreatment also reduced the intestinal microvascular injury after intestinal IR.

Conclusion

Treatment with an anti-TNF antibody resulted in significant attenuation of lung injury following intestinal IR, which is at least partially TNF mediated. The data indicate that TNF is an important trigger for upregulation of pulmonary endothelial and neutrophil adhesion molecules after intestinal IR.

S100beta correlates with neurologic complications after aortic operation using circulatory arrest

BACKGROUND

Astrocyte protein S100beta is a potential serum marker for neurologic injury. The goals of this study were to determine whether elevated serum S100beta correlates with neurologic complications in patients requiring hypothermic circulatory arrest (HCA) during thoracic aortic repair, and to determine the impact of retrograde cerebral perfusion (RCP) on S100beta release in this setting.

METHODS

Thirty-nine consecutive patients underwent thoracic aortic repairs during HCA; RCP was used in 25 patients. Serum S100beta was measured preoperatively, after cardiopulmonary bypass, and 24 hours postoperatively.

RESULTS

Neurologic complications occurred in 3 patients (8%). These patients had higher postbypass S100beta levels (7.17 +/- 1.01 microg/L) than those without neurologic complications (3.63 +/- 2.31 microg/L, p = 0.013). Patients with S100beta levels of 6.0 microg/L or more had a higher incidence of neurologic complications (3 of 7, 43%) compared with those who had levels less than 6.0 microg/L (0 of 30, p = 0.005). Retrograde cerebral perfusion did not affect S100beta release.

CONCLUSIONS

Serum S100beta levels of 6.0 microg/L or higher after HCA correlates with postoperative neurologic complications. Using serum S100beta as a marker for brain injury, RCP does not provide improved cerebral protection over HCA alone.

A new predictive model for adverse outcomes after elective thoracoabdominal aortic aneurysm repair

BACKGROUND

Recent recommendations have emphasized individualized treatment based on balancing a patient's risk of thoracoabdominal aortic aneurysm rupture with the risk of an adverse outcome after surgical repair. The purpose of this study was to determine which preoperative risk factors currently predict an adverse outcome after elective thoracoabdominal aortic aneurysm repair.

METHODS

A single, composite end point termed adverse outcome was defined as the occurrence of any of the following: death within 30 days, death before discharge from the hospital, paraplegia, paraparesis, stroke, or acute renal failure requiring dialysis. A risk factor analysis was performed using data from 1,108 consecutive elective thoracoabdominal aortic aneurysm repairs.

RESULTS

The incidence of an adverse outcome was 13.0% (144 of 1,108 patients); predictors included preoperative renal insufficiency (p = 0.0001), increasing age (p = 0.0035), symptomatic aneurysms (p = 0.020), and extent II aneurysms (p = 0.0001). These risk factors were used to construct an equation that estimates the probability of an adverse outcome for an individual patient.

CONCLUSIONS

This new predictive model may assist in decisions regarding elective thoracoabdominal aortic aneurysm operations. For patients who are acceptable candidates, contemporary surgical management provides favorable results.

Role of tumour necrosis factor in lung injury caused by intestinal ischaemia-reperfusion

BACKGROUND

Despite the well known inflammatory effects of tumour necrosis factor alpha (TNF), the mechanism of TNF-mediated lung injury following ischaemia-reperfusion (I/R) is still unclear. In this study, the role of TNF in the development of acute lung injury following intestinal I/R was investigated.

METHODS

Male Wistar rats underwent either sham operation (n = 10), 1 h of superior mesenteric artery occlusion and 2 h of reperfusion (I/R, n = 10), or pretreatment with anti-TNF polyclonal antibody 2 mg/kg and I/R (n = 6). Lung injury was evaluated by Evans blue dye concentration, immunohistochemical staining and morphometric analysis. Intestinal injury was assessed by Evans blue dye concentration and histological examination.

RESULTS

Intestinal I/R resulted in lung injury characterized by an increase in Evans blue dye concentration, neutrophil sequestration, and obvious staining for expression of pulmonary CD11b and CD18. Pretreatment of animals with anti-TNF antibody led to a reduction in the sequestration of neutrophils, and a decrease in expression of pulmonary intracellular adhesion molecule 1 and CD18. Anti-TNF antibody pretreatment also reduced the intestinal microvascular injury but not histological grade after intestinal I/R.

CONCLUSION

Treatment with an anti-TNF antibody resulted in a significant attenuation of lung injury following intestinal I/R. The data indicate that TNF is an important trigger for upregulation of pulmonary endothelial and neutrophil adhesion molecules after intestinal I/R.

Prevention of deleterious effects of reperfusion injury using one-week high-dose allopurinol

Allopurinol has been widely used to reduce the severity of the reperfusion injury. However, conflicting data have been reported regarding the dosage, the duration of the timing, and the administrative regimen of the drug. The aim of this study was, therefore, to evaluate the effects of short versus long periods of allopurinol pretreatment on the anastomotic healing of intestines, directly after being subjected to ischemia-reperfusion (IR) stress. Furthermore, the effects of an allopurinol pretreatment on the survival rate following IR stress, was also assessed. One hundred thirty-seven male Wistar rats with a median weight of 235 (range, 180-275) g used in the study. In group I (control group, N = 20) superior mesenteric artery (SMA) and collateral vessels were isolated but not occluded. In group II, the profound IR group (PIR, N = 42), the SMA was occluded immediately distal to the aorta with collateral interruption using an atraumatic arterial clip for 30 min. In group III [two days of allopurinol (ALL) pretreatment group, 2ALL, N = 38], allopurinol (100 mg/kg body wt) was given intraperitoneally on a daily basis for two days prior to the experiment. In group IV (seven days of allopurinol pretreatment group, 7ALL, N = 37), the same pretreatment and the allopurinol schedule was performed for seven days before surgery. All animals underwent 3 cm of ileal resection and primary anastomosis, 10 cm proximal to ileocecal valve. Within each group, animals were anesthetized either on the third or seventh postoperative days. Abdominal wound healing, intraabdominal adhesions, anastomotic complications, anastomotic bursting pressure measurements, and bursting site were recorded as were the histopathologic evaluation. No rats in group I, 20 rats in group II, 18 rats in group III, and 7 rats in group IV died (P = 0.0003). Anastomotic dehiscence was found in one of 20 group I, in 11 of 22 in group II, in 9 of 20 in group III, and in 3 of 30 in group IV (P = 0.0003). On the third and seventh days, the median bursting pressures of the anastomosis were determined: 42 and 235 mm Hg in group I, 17 and 105 mm in Hg in group II, 22 and 183 mm Hg in group III, and 36 and 214 mm Hg in group IV (P < 0.0001). The burst occurred at the anastomoses in all animals tested on the third postoperative day, one in group I, six in group II, four in group III and one in group IV on the seventh postoperative day (P < 0.01). All deleterious effects of reperfusion injury on intestinal anastomosis healing, including survival rates and the histopathological parameters, were significantly prevented by seven days, but not two days, of high-dose allopurinol pretreatment.

Cerebrospinal fluid drainage in thoracoabdominal aortic surgery

Paraplegia caused by spinal cord ischemia remains a devastating complication after surgical repair of thoracoabdominal aortic aneurysms. Cerebrospinal fluid (CSF) drainage has been advocated as a protective adjunct to reduce the incidence of postoperative neurologic deficits. Studies in animals have shown that CSF drainage during thoracic aortic clamping reduces CSF pressure, improves spinal cord blood flow, and prevents paraplegia. Previous retrospective and randomized clinical studies, however, have been inconclusive because of confounding factors and other limitations. A recent prospective randomized trial focusing solely on CSF drainage during repair of extent I and II thoracoabdominal aortic aneurysms indicated an 80% reduction in the relative risk of paraplegia and paraparesis in patients who received this adjunct. Consequently, CSF drainage has emerged as an important addition to the multimodality strategy for preventing postoperative spinal cord deficits.

Effect of ischemia/reperfusion as a systemic phenomenon on anastomotic healing in the left colon

Intestinal ischemia/reperfusion provokes a local inflammatory response leading to a systemic inflammatory state. In this study we aimed to assess the effects of intestinal ischemia/reperfusion injury on anastomotic healing in the left colon with an intact vascular supply. A total of 94 Wistar albino rats were divided into three groups: sham-operated control (group I, n = 25), 30 minutes of intestinal ischemia/reperfusion (group II, n = 40), and 7-day allopurinol pretreatment and intestinal ischemia/reperfusion (group III, n = 29). After the reperfusion experiment, a segmental left colon resection and anastomosis were done. On postoperative days 3 and 7 anastomotic bursting pressure, anastomotic and operative complications, and intraabdominal adhesions were assessed. Mortality rates were 1/25, 16/40, and 4/29 for groups I, II, and III, respectively (p = 0.001). There was no difference among the groups for wound and anastomotic healing parameters evaluated by macroscopic criteria. On postoperative day 7 the mean bursting pressures were 220.3 +/- 18.5, 162.0 +/- 21.0, and 213.9 +/- 24.7 for groups I, II, and II, respectively (p = 0.000). Significantly dense adhesions were found in group II (p = 0.000). Allopurinol pretreatment prevented the effects of ischemia/reperfusion on anastomotic healing of the left colon. Intestinal/ischemia reperfusion causes impairment of anastomotic healing of the left colon. In addition to remote organ effects, reperfusion injury may affect anastomotic healing in the viscera with an intact vascular supply.

Mortality and paraplegia after thoracoabdominal aortic aneurysm repair: a risk factor analysis

BACKGROUND

Recent recommendations regarding thoracoabdominal aortic aneurysm (TAAA) management have emphasized individualized treatment based on balancing a patient's calculated risk of rupture with their anticipated risk of postoperative death or paraplegia. The purpose of this study was to enhance this risk-benefit decision by providing contemporary results and determining which preoperative risk factors currently predict mortality and paraplegia after TAAA surgery.

METHODS

Risk factor analyses based on data regarding 1,220 consecutive patients undergoing TAAA repair from 1986 through 1998 were performed using multiple logistic regression with step-wise model selection.

RESULTS

The 30-day mortality rate was 4.8% (58 of 1,220) and the incidence of paraplegia was 4.6% (56 of 1,206). For elective cases, predictors of operative mortality included renal insufficiency (p = 0.0001), increasing age (p = 0.0005), symptomatic aneurysms (p = 0.0059), and extent II aneurysms (p = 0.0054). Extent II aneurysms (p = 0.0023) and diabetes (p = 0.0402) were predictors of paraplegia.

CONCLUSIONS

These risk models may assist in decisions regarding elective TAAA operations. For patients who are acceptable candidates, contemporary surgical management provides favorable results.

Intestinal ischemia and reperfusion impairs vasomotor functions of pulmonary vascular bed

OBJECTIVE

To investigate the effects of intestinal ischemia and reperfusion (I/R) on the pulmonary vascular endothelium and smooth muscle.

SUMMARY BACKGROUND DATA

Respiratory failure is an important cause of death and complications after intestinal I/R. Although the mechanism of respiratory failure in this setting is complex and poorly understood, recent studies of lung injury suggest that endothelial dysfunction may play a significant role.

METHODS

A rat model of acute lung injury was studied after 60 minutes of superior mesenteric arterial occlusion followed by either 120 or 240 minutes of reperfusion. The pulmonary vasomotor function was examined in isolated lungs perfused at a constant flow rate.

RESULTS

Sixty minutes of intestinal ischemia followed by 120 or 240 minutes of reperfusion led to a significant reduction in the ability of the pulmonary vasculature to respond to angiotensin II, acetylcholine, and calcium ionophore but not to nitroglycerin. The vasoconstriction response to N(G)-nitro-L-arginine methyl ester, which is a measure of basal nitric oxide release, was diminished in the 240-minute reperfusion group. Intestinal I/R was also associated with pulmonary leukosequestration and increased pulmonary microvascular leakage.

CONCLUSIONS

Basal and agonist-stimulated release of nitric oxide from the pulmonary vascular endothelium and the ability of pulmonary smooth muscle to contract in response to angiotensin II were impaired by intestinal I/R. Such functional impairment in both pulmonary vascular endothelium and smooth muscle may contribute to the alveolocapillary dysfunction and pulmonary hypertension found in acute lung injury after intestinal I/R.

Obstructive jaundice promotes bacterial translocation in humans

BACKGROUND/AIMS

Significant bacterial translocation was demonstrated following experimental biliary obstruction, however very little is known about the importance and the prevalence of gut-origin sepsis in obstructive jaundice patients. Therefore, the aim of this study was to investigate the concept of gut-origin sepsis in obstructive jaundiced patients and its clinical importance.

METHODOLOGY

Twenty-one patients requiring laparotomy for obstructive jaundice (group I) and thirty patients operated on electively mainly for chronic cholecystitis (group II) were studied. Peritoneal swab, mesenteric lymph node, portal venous blood, liver wedge biopsy and bile were sampled for culture immediately after opening the peritoneum. Additionally, peripheral blood samples were taken pre- and post-operatively from all patients. Post-operatively, patients were monitored for infectious complications.

RESULTS

The mean serum bilirubin concentration, gamma glutamyl transferase and alkaline phosphatase levels in jaundiced patients before therapeutic intervention were significantly higher than in control patients. Five patients demonstrated bacterial translocation in group I (24%), whereas only one did so in group II (3.5%, p < 0.05). Septic complications were detected in three patients, but only in two with bacterial translocation in group I. There was one patient with bacterial translocation who had septic complication in group II.

CONCLUSIONS

The present study demonstrated that obstructive jaundice significantly promotes bacterial translocation in humans, however, its clinical importance has yet to be defined.

Management of thoracic aortic graft infections

BACKGROUND

We reviewed our experience managing patients with thoracic aortic graft infections to evaluate their clinical characteristics and outcomes of treatment.

METHODS

Records of 20 consecutive patients with thoracic aortic graft infections managed over a 7 year period were retrospectively reviewed. Current follow-up status was obtained for all survivors. RESULTS; Nineteen patients (95%) underwent surgical treatment. Graft excision and in situ replacement were performed using Dacron grafts (10/19, 53%) or cryopreserved homografts (5/19, 26%). Three pseudoaneurysms were managed by debridement and primary repair. Although 30 day postoperative survival was 89% (17/19), in-hospital mortality occurred in 8 patients (42%). Infected thoracoabdominal aortic grafts were universally fatal. Of 6 patients with infected composite valve grafts, both patients who received new composite valve grafts died and all 4 who received homografts survived (p = 0.067).

CONCLUSIONS

Infections involving thoracic aortic grafts continue to carry a high mortality rate, especially in patients with polymicrobial infections, thoracoabdominal aortic graft infections, and composite valve graft infections. Use of homografts in the latter situation may improve outcome.

Colonic anastomotic healing after preoperative chemo-radiotherapy in rat

PURPOSE

To prevent micrometastasis at an earlier stage and to increase the lateral or circumferential tumor free margins, there is a rationale for neo-adjuvant chemo-radiotherapy in patients with colorectal cancer. In order to investigate the effects of such a protocol on colonic anastomotic healing, an experimental study resembling the clinical use of neo-adjuvant concomitant 5-FU+ irradiation treatment of colorectal cancer was conducted.

MATERIALS AND METHODS

Seventy-one male Wistar rats were divided into three groups: a control group (I) underwent left colon resection and primary anastomosis (n = 20); a sham-treated group (II, n = 20); and a study group (III) which received fractionated irradiation to the whole pelvis to a total dose of 22 Gy, 5.5 Gy per fraction, in four consecutive days with linear accelerator and concomitant intra-peritoneal 5-FU (20 mg/kg/day) for five consecutive days. The last fraction of irradiation and the last injection were given four and three days before colonic resection and anastomosis, respectively. Within each group one-half of the animals were anesthetized on the third postoperative day and one-half on the seventh postoperative day. Abdominal wound healing, intraperitoneal adhesions, anastomotic complications, and anastomotic bursting pressure measurements were recorded. Following these measurements the anastomotic segment was resected for hydroxyproline content, myeloperoxidase activity, and histopathological evaluation.

RESULTS

There were no differences in the abdominal wound healing, intraperitoneal adhesions, and anastomotic complications between groups. At three and seven days, the mean bursting pressures of the anastomoses were 36.5 mm Hg and 208 mm Hg in group I, 34.5 and 228 in group II, and 27 and 167 in group III, respectively (p < 0.01, group III vs both groups I and II on day seven). The burst occurred at the anastomosis in all animals tested on the third postoperative day, and one in group I (10%), none in group II, and four in group III (40%) on the seventh postoperative day.

CONCLUSION

Preoperative pelvic fractionated irradiation and concomitant 5-FU delays anastomotic healing.

Histological evaluation of colonic anastomotic healing in the rat following preoperative 5-fluorouracil, fractionated irradiation, and combined treatment

There is a growing interest in neoadjuvant chemo- and radiotherapy as a treatment modality for colorectal cancer which could affect mechanical and biochemical parameters of anastomotic healing. This study investigated the effect of such protocols on colonic anastomotic healing by evaluating the histopathological parameters. One hundred and sixty male Wistar rats were divided into six groups: a control group (I, n = 20), a saline group (II, n = 30) which received 1 ml NaC1 intraperitoneally, a sham-irradiated group (III, n = 20), a 5-fluorouracil (5-FU) group (IV, n = 30), which received 5-FU (20 mg/kg) intraperitoneally for 5 consecutive days, an irradiated group (V, n = 40) which received fractionated irradiation to the whole pelvis to a total dose of 22 Gy, 5.5 Gy per fraction on 4 consecutive days, and a concomitant 5-FU + irradiation group (VI, n = 20) which received 5-FU as in group IV and irradiated as in group V. All groups underwent left colonic resection with primary anastomosis, and the last fraction of irradiation and the last injection were given 4 and 3 days before the operation, respectively. Within each group one half of the animals were killed on the third postoperative day and the other half on the seventh postoperative day. After the resection of the anastomotic segments, histopathological examination was evaluated. Apposition of the wound edges of the mucosa and the muscularis were not affected by the therapy. The level of granulocytes was high, inflammatory exudate and necrosis persisted, granulation tissue formation was delayed, and the levels of macrophages and fibroblasts were low. We conclude that colonic anastomotic healing can be affected by the administration of preoperative chemotherapy, irradiation, and chemoirradiation.

Reperfusion injury delays healing of intestinal anastomosis in a rat

BACKGROUND

Revascularization of ischemic bowel may induce further local tissue damage due to reperfusion injury. Therefore, we aimed to investigate the effect of ischemia-reperfusion injury on the healing of intestinal anastomosis in experimental models.

METHODS

One hundred and two male Wistar rats were divided into three groups: a control group (group I, n = 23); an ischemia group (group II, n = 32), in which only the superior mesenteric artery (SMA) was occluded for 30 minutes; and a profound ischemia group (group III, n = 47), in which SMA was occluded as well as collateral vessels for 30 minutes. The pulsations were seen to return to marginal vessels and the bowels began to appear pinker and healthier in all groups following the restoration of arterial flow. Then, all animals underwent a 3-cm ileal resection and primary anastomosis, 10 cm proximal to the ileocecal valve. Within each group, animals were anesthetized either on the third or seventh postoperative days. Abdominal wound healing, intraabdominal adhesions, anastomotic complications, anastomotic bursting pressure measurements, and bursting site were recorded.

RESULTS

Statistically significant differences were detected in intraperitoneal adhesion scores in group II and III (P <0.001). Anastomotic dehiscence was found in 2 of 23 (9%) in group I, 5 of 32 (16%) in group II, and 16 of 47 (34%) in group III (P <0.001). On the third and seventh days, the median bursting pressures of the anastomosis were determined to be 42 mm Hg and 250 mm Hg in group I, 46 and 253 in group II, and finally 19 and 90 mm Hg in group III (P <0.01). The burst occurred at the anastomoses in all animals tested on the third postoperative day, none in group I, 4 (28%) in group II, and 8 (67%) in group III on the seventh postoperative day (P <0.005).

CONCLUSION

The present study demonstrated that ischemia-reperfusion impairs anastomotic healing. Despite the fact that the intestines are well perfused and viable after revascularization, one must bear in mind that intestinal reperfusion may compromise anastomotic healing.

Effects of preoperative fractionated irradiation on left colonic anastomoses in the rat

PURPOSE

Radiotherapy is frequently used as a (neo)adjuvant to surgery in colorectal cancer patients, and because such therapy could influence the integrity of the anastomosis, we decided to investigate the effect of preoperative irradiation on colonic anastomosis.

METHODS

Seventy-two male Wistar rats, weighing 200 to 348 g, were divided into three groups: a control group (I) underwent left colon resection and primary anastomosis (n = 20); a sham irradiated group (II, n = 20); a study group (III) that received fractionated irradiation to the whole pelvis (anterior-posterior pelvic field), for a total dose of 22 Gy, 5.5 Gy per fraction, on four consecutive days with linear accelerator (n = 32). Four days after irradiation, both Groups II and III underwent the same operation as performed in Group I. Within each group, one-half of the animals were anesthetized on the third postoperative day and one-half on the seventh postoperative day. Abdominal wound-healing, anastomotic complications, and anastomotic bursting pressure measurements were recorded. Following these measurements, the anastomotic segment was resected for hydroxyproline content and myeloperoxidase activity.

RESULTS

Irradiated animals had more pronounced weight loss during therapy. There were no differences with abdominal wound-healing, intraperitoneal adhesions, and anastomotic complications between groups. At days 3 and 7, mean bursting pressures of the anastomosis were determined at 36.5 and 208 mmHg in Group I, 34.5 and 228 mmHg in Group II, and 25 and 150 mmHg in Group III, respectively (P < 0.01 Group III vs. both Groups I and II on days 3 and 7). The burst occurred at the anastomosis in all animals tested on the third postoperative day and one in Group I (10 percent), none in Group II, and six in Group III (37.5 percent) on the seventh postoperative day. In addition, hydroxyproline content and myeloperoxidase activity was significantly lower in Group III.

CONCLUSION

Although preoperative fractionated irradiation significantly decreased the anastomotic bursting pressure and more burst occurred in the anastomotic line on postoperative day 7, the clinical outcome was similar among the groups.

Experimental study of the effect of preoperative 5-fluorouracil on the integrity of colonic anastomoses

BACKGROUND

Despite curative resection for colorectal cancer, many patients develop recurrence at the primary site or distant organs. These patients are candidates for (neo)-adjuvant chemotherapy. Very little is known about the effect of preoperative 5-fluorouracil (FU) on the healing of colonic anastomoses. The aim of this study was to assess this in a rat model.

METHODS

Eighty male Wistar rats, weighing 160-215 g, were divided into three groups; (1) a control group underwent left colon resection and primary anastomosis (n = 20); (2) a sham group received 1 ml saline intraperitoneally (n = 30); (3) a study group received 5-FU intraperitoneally (20 mg kg-1). Both saline and 5-FU injections were given intraperitoneally for 5 days before operation.

RESULTS

There was no difference in the rate of wound complications, intraperitoneal adhesions and anastomotic complications among the groups. Three and seven days after operation, mean bursting pressure of the anastomosis was 36.5 and 198 mmHg in group 1, 34 and 200 mmHg in group 2, and 39 and 190 mmHg in group 3 respectively (P not significant). Although the myeloperoxidase and hydroxyproline content were significantly lower after 5-FU therapy (P < 0.01, compared with others), the clinical outcome was similar.

CONCLUSION

Preoperative 5-FU consecutive days before operation had no effect on the healing of colonic anastomoses.

Trace elements and superoxide dismutase in benign and malignant breast diseases

This study was planned to determine the probable changes in trace element levels and superoxide dismutase (SOD) activity in women with neoplastic breast diseases. Measurements were performed in three different groups. The first group consisted of 20 healthy women, control group, the second group contained 16 patients with benign breast disease and the third group contained 39 patients with malignant breast disease. The trace element concentrations were determined by using atomic absorption spectrophotometry and SOD activity by using spectrophotometry. When compared with the control values, the plasma copper levels were slightly increased in the second group and significantly in the third group (p < 0.001). The difference between the benign and malignant groups was also significant (p < 0.001). The red cell copper values showed a marked decrease in both groups (p < 0 001). Although there were increases in the plasma zinc levels of both patient groups, the differences were not significant statistically. But, the red cell zinc values showed an significant increase in benign and malignant patients compared to the control group (p < 0.001) (p < 0.001). The plasma magnesium and red cell magnesium values did not show significant differences. The red cell SOD activity showed an significant increase in the benign and malignant patient groups (p < 0.001). The results of this study suggested that reactive oxygen metabolites may play a pathogenetic role in the both benign and malignant tumor development, which is reflected by the change in SOD activity, and in trace element concentrations.

The comparison of the responsiveness of human isolated internal mammary and gastroepiploic arteries to levcromakalim: an alternative approach to the management of graft spasm

AIMS

We studied the effectiveness of levcromakalim, a potassium channel opener (KCO), in the prevention and reversal of spasm in arterial grafts used in coronary artery bypass operations, namely, internal mammary artery (IMA) and gastroepiploic artery (GEA).

METHODS

Spasm was mimicked in vitro in arterial rings from 109 patients by increasing the vascular tension with noradrenaline, the thromboxane analogue U46619, endothelin-1 and K+.

RESULTS

GEA displayed considerably higher contractile force to these agents than IMA. Pretreatment with levcromakalim depressed significantly the maximal contractile responses (either absolute or relative) to noradrenaline and U46619 but did not affect those of endothelin-1 and K+ in both of the arteries. Sensitivities (to all agents, except to endothelin-1) decreased significantly after levcromakalim. In experiments evaluating the antispasmodic activity of levcromakalim, a higher relaxant capacity was observed in GEA than IMA (for K+ contraction; IMA: 31.32 +/- 3.83%, n= 13 vs GEA: 98.01 +/- 0.71%, n=7, P<0.05). This different activity of levcromakalim between two arterial grafts was apparent even when GEA rings were contracted to higher force (g) than that of IMA (for K+ contraction; GEA: 72.56 +/- 4.96%, n = 7). Responses to levcromakalim were similar in IMA and GEA when endothelin-1 was used as the spasmogenic agent (IMA: 80.98 +/- 4.85%, n=10 vs GEA: 91.93 +/- 3.17%, n=7, P>0.05).

CONCLUSIONS

Our results provide evidence that levcromakalim may have a therapeutic value in the treatment of spasm of coronary artery bypass grafts, especially GEA.

Ischemia and reperfusion injury: prevention of pulmonary hypertension and leukosequestration following lower limb ischemia

Ischemia is a common clinical event with potentially serious consequences. The major part of tissue damage occurs upon reperfusion and is mediated by activated neutrophils. Ischemia reperfusion injury is manifested by oedema and increased microvascular permeability. This study tested cardiopulmonary functions following 2 h of lower limb ischemia. Anesthetized dogs were randomized into three groups: nonischemic sham dogs (n = 4), ischemic control dogs (n = 8) and ischemic dogs pretreated with prostaglandin (PG)E1 (n = 8). In control animals, mean pulmonary artery pressure (mPAP) increased 1 min after declamping from 13.37 +/- 2.61 mmHg to 16.88 +/- 3.68 mm Hg (P < 0.05). Pulmonary microvascular pressure (Pmv) increased within 1 minute of reperfusion from 7.71 +/- 1.87 mm Hg to 10.54 +/- 3.71 mm Hg (P < 0.05). These changes are consistent with increased lung microvascular permeability. White blood cell count fell slightly but not significantly and lung histology showed leukosequestration in alveoli of 171 +/- 22 polymorphonuclear leukocyte (PMN)/10 high powered fields (HPF) in the ischemic control group compared with 121 +/- 56 PMN/10 HPF in the sham group (P < 0.05). Systemic arterial pressure, cardiac output, central venous pressure and pulmonary artery wedge pressure were unaffected. In animals pretreated with PGE1, mPAP and Pmv were unchanged during reperfusion. Lung histologic findings appeared normal and leukosequestration was not observed. PMN counts in alveoli showed 95 +/- 26 PMN/10 HPF, lower than in ischemic control animals (P < 0.05). These data indicate that lower limb ischemia during reperfusion leads to pulmonary hypertension and leukosequestration, PGE1 infusion is effective in limiting ischemia reperfusion injury.

Evaluation of peripheral vascular system disorders in vascular symptom--free Behçet's disease

Vascular involvement in Behçet's disease has been reported in 7-40% of patients in the literature and nearly 8% of these will have serious vascular complications during follow-up. So far, little information is available on the extent of vascular involvement in patients with Behçet's disease who are free of vascular symptoms. The study comprised 34 individuals with Behçet's disease who were free of vascular symptoms and 47 healthy volunteers. Both groups underwent non-invasive peripheral vascular examination consisting of Doppler, photoplethysmography, and segmental pressure measurements and determination of ankle-brachial pressure and femoro-brachial pressure indices. Venous insufficiency was detected in 22 of 68 lower extremities examined in the Behçet's disease group and in ten of 94 in the controls (P < 0.001). The number of extremities with an ankle-brachial pressure index of less than 1.00 for both the anterior and posterior tibial arteries, was significantly higher in the Behçet's disease group (P < 0.001). The femoro-brachial pressure index was significantly higher in the controls than in the Behçet's disease group (1.32 versus 1.23 for the right leg, P < 0.05; 1.31 versus 1.22 for the left leg, P < 0.03). Vascular symptom-free patients with Behçet's disease seem to have a high incidence of peripheral vascular involvement compared with healthy controls.

The risk factors in central venous catheter-related thrombosis

Catheter-related venous thrombosis is one of the most important complications of central venous catheters. The aim of this prospective study was to assess the risk factors that may be important in the development of catheter-related thrombosis. Multiple lumen (n = 20) and single lumen (n = 24) polyurethane catheters were inserted to the subclavian vein by the infraclavicular approach in 44 consecutive patients. All variables that may be significant for the development of thrombosis related to the patient, the catheter, the insertion technique and the solution administered through the line were recorded. Eighteen of 44 patients (40%) were found to have venous thrombosis. Two factors were found to correlate significantly with the development of central venous catheter-related thrombosis, namely the number of vein punctures (one vs two punctures, P < 0.01) and the composition of solution (fluid replacement vs total parenteral nutrition, P = 0.01).

The diagnostic value of colour Doppler ultrasound in central venous catheter related thrombosis

AIM

This prospective study was performed to establish the correlation between colour Doppler ultrasound (US) observations and venography in detecting catheter-related thrombosis.

METHOD

Forty-four patients with subclavian venous catheters were studied. The sensitivity and specificity of colour Doppler US was determined for the diagnosis of central venous thrombosis and compared with contrast venography. Criteria considered to show the presence of catheter-related thrombosis included visualization of thrombus (T), absence of spontaneous flow (S), absence of phasicity of flow with respiration (P), incompressibility of the vein with probe pressure (C) and visualization of increased venous collaterals (V).

RESULTS

Analysing each variable separately, P had the highest sensitivity (94%) and S had the highest specificity (100%). The best combinations for diagnosis were T+P, P+S, and T+P+S with a sensitivity of 94% and specificity of 88%. Overall diagnostic value of colour Doppler US had a sensitivity of 94% and specificity of 96%.

CONCLUSION

Colour Doppler US is a reliable method for detecting central venous catheter-related thrombosis, especially if several parameters are evaluated in combination.

Haemodynamic effects of pneumoperitoneum during laparoscopic cholecystectomy: a prospective comparative study using bioimpedance cardiography

The haemodynamic effects of increased intra-abdominal pressure during laparoscopic cholecystectomy in 22 patients were compared with those in 11 patients undergoing open cholecystectomy; bioimpedance cardiography was used for monitoring at predetermined time intervals. In the laparoscopy group stroke volume, cardiac and ejection velocity indices were significantly decreased and the total peripheral resistance index was significantly increased during the insufflation period when compared with preinsufflation and corresponding values in the group undergoing open operation. Routine intraoperative parameters such as heart rate and blood pressure did not show any significant change or indicate alterations in cardiovascular performance during laparoscopic procedures. Continuous non-invasive cardiovascular monitoring by bioimpedance cardiography may be useful in patients with limited cardiac function.

The endothelium-derived relaxing factor-mediated acetylcholine response of the arterial perfusion pressure after cold storage of the isolated rabbit kidney

The vasodilatation induced by acetylcholine (ACh) in a rabbit isolated perfused kidney was abolished when the tissue was exposed to cold ischemia for 72 h in Euro-Collins (EC) solution. This vasodilatation is due to the release of endothelium-derived relaxing factor (EDRF) from renal vasculature as evidenced by the attenuation following methylene blue pretreatment. When kidneys were preserved in EC solution containing UK 38485, a thromboxane synthase inhibitor, or nicardipine, a calcium channel blocker, ACh-induced vasodilatation persisted after 72 h of cold ischemia. These results were taken as evidence of tissue protective activity of UK 38485 and nicardipine and have promising implications for cadaveric kidney transplantation.

Thromboxane synthase inhibitor, UK 38485, prevents renal injury in the rabbit isolated perfused kidney exposed to cold ischemia

Recent studies have indicated that, the administration of thromboxane A2 (TxA2) inhibitors improved renal functions in experimental renal allograft transplantation. Thus TxA2, a vasoconstrictor metabolite of arachidonic acid, may play a role in renal function and blood flow during hypothermic storage. The aim of the present study was to evaluate the cytoprotective effect of TxA2 synthase inhibitor, UK 38485, on altered renal function due to cold ischemia for 24 and 72 h. Experiments were performed in isolated perfused kidney from adult rabbits. Kidneys were perfused with Euro-Collins (EC) containing UK 38485 and incubated with the same solution in a beaker exposed to cold ischemia for 24 and 72 h. The same procedure was applied to the control kidneys in EC solution alone. Vascular responses and urinary output to noradrenaline, angiotensin II, endothelin-1, acetylcholine, and sympathetic stimulation were assessed as the functional activity of kidney. The addition of UK 38485 to EC solution increased the preservation time of kidney and protects the vascular endothelial regulatory functions and urine excretion when compared to EC alone. The results of the present study can be taken as an evidence of the cytoprotective effect of the UK 38485 and might be useful for kidney preservation.

Predictive value of colour Doppler ultrasonography in detecting failure of vascular access grafts

The predictive role of colour Doppler ultrasonography in determining the initial success and long-term patency of polytetrafluoroethylene (PTFE) vascular access grafts for haemodialysis was investigated. Two groups of patients were studied. The upper extremities of 21 patients in the control group were assessed by clinical examination only; those of 17 in a second group (Doppler group) were also assessed by ultrasonography before and after operation. Straight PTFE vascular access grafts were used between the brachial artery and axillary vein in all patients. The median preoperative brachial artery flow rate was significantly lower in patients who later developed graft thrombosis (66 versus 87 ml/min, P < 0.01), as was the median postoperative graft flow rate (480 versus 800 ml/min, P < 0.001). Routine preoperative and postoperative colour Doppler ultrasonography is recommended for every patient in whom a vascular access graft is planned.

The effect of nicardipine on renal functions following 72-hour cold ischemia

The aim of the study was to investigate the cytoprotective effect of a calcium channel blocker, nicardipine, on altered renal function due to cold ischemia for 72 h. The experiments were performed on isolated perfused kidneys from adult rabbits. Kidneys were perfused with either standard Euro-Collins (EC) solution (n = 7) or EC containing nicardipine (n = 6) and then incubated with the same preservation solutions in a beaker exposed to cold ischemia for 72 h at +4 degrees C. In the control group the same procedure was applied to untreated kidneys (n = 6) which were exposed to cold ischemia for 30 min. Vascular responses and urinary output to noradrenaline, angiotensin II, endothelin-1, acetylcholine and sympathetic stimulation were assessed as the functional activities of the kidney. The responses of the preserved kidneys were compared following cold ischemic conditions. The results indicate that the addition of nicardipine to EC solution protects the vascular endothelial regulatory function and urine excretion; therefore, dihydropyridine calcium channel blockers might be useful for kidney preservation.

Vascular involvement in Behçet's disease: 8-year audit

Behçet's disease is a multisystemic disorder characterized by recurrent ulcers of the mouth and genitalia and relapsing iritis. Four types of vascular lesion are recognized in Behçet's disease: arterial occlusions, aneurysms, venous occlusions, and variceal development. The incidence of vascular involvement reported in the literature ranges from 7% to 29%. The aim of this study was to determine the rate of vascular involvement in Behçet's disease at our hospital between 1983 and 1992. Of 1200 patients with Behçet's disease, 173 (14.4%) had venous manifestations and 19 (1.6%) had arterial manifestations (in some patients more than one organ was involved). In the group of patients with venous manifestations, there were 154 (12.8%) with venous thrombosis, 17 (1.4%) with vena cava superior syndrome, 5 (0.4%) with inferior vena cava syndrome, 5 (0.4%) with varices, 2 with upper extremity venous thrombosis, 1 with internal jugular vein thrombosis, 1 with cavernous sinus thrombosis, and 1 with hepatic vein thrombosis. In the arterial manifestation group there were 7 femoral, 3 abdominal, 3 popliteal, 2 iliac, 2 pulmonary, 1 axillary, and 1 carotid artery aneurysm as well as 3 arterial occlusions. We concluded that vascular surgeons dealing with young adults should bear Behçet's disease, an uncommon clinical entity, in mind.

Use of autologous fibrin glue in the treatment of splenic trauma: an experimental study

There is little doubt that preserving the spleen will contribute to a much more favourable outcome in patients undergoing splenic surgery, as a result of avoiding the well known risks of splenectomy. Among many operative methods described for splenic salvage, application of autologous fibrin glue (AFG) is particularly promising because of its unique characteristics. The use of AFG has been evaluated and its efficacy and tissue compatibility assessed in the treatment of splenic trauma in 15 partially splenectomized New Zealand White rabbits. The application of the AFG to the resected splenic surface achieved complete haemostasis in all animals. The animals were divided into four groups and were killed at varying intervals ranging from 24 h to 10 weeks. During re-exploration there was no evidence of recurrent bleeding and histopathological examination revealed progressive absorption of the AFG with a minimal inflammatory response. It is concluded that AFG is an effective haemostatic agent with good systemic and local compatibility and can be used in splenic salvage, which thereby avoids the use of non-autologous products with their risks of disease transmission.