Regional distribution of blood flow during proximal aortic cross-clamping: an experimental study using coloured microspheres.

OBJECTIVE: To investigate the effect of thoracic aortic cross-clamping on blood perfusion of the brain, spinal cord, heart, muscular tissue and visceral organs. MATERIAL AND METHODS: Nine pigs underwent 30 min cross-clamping of the descending thoracic aorta. Multiple coloured microspheres (15.0 microm +/- 0.1) were infused into the left ventricle before and during aortic cross-clamping (XC) and after declamping (DC). Tissue samples were analysed by spectrophotometry. RESULTS: Blood perfusion of the middle and lower segments of the spinal cord was significantly reduced during aortic XC. Perfusion of the brain was not significantly altered by aortic XC, while perfusion of myocardium increased 3-fold. During XC, perfusion of the deltoid muscle and diaphragm increased 5-fold and 13-fold, respectively, while a decrease was found in the gluteus muscle. Renal blood flow was significantly reduced during XC. Finally, XC induced a significant decrease of perfusion in the bowel, spleen, liver and pancreas. CONCLUSION: During XC of the thoracic aorta, the perfusion of the muscular tissue was significantly increased proximal to the level of XC. The circulation of the brain was unchanged, probably because of autoregulatory mechanisms. Blood perfusion of the myocardium increased 3-fold during XC.

Quality of data reported on abdominal aortic aneurysm repair--a comparison between a national vascular and a national administrative registry.

OBJECTIVE: To study consistency of data and completeness of reporting in a national vascular registry, NorKar, and a national administrative registry, The Norwegian patient register (NPR). DESIGN: Comparative registry-based national study supplemented with a comprehensive control of patients registered in one major hospital. MATERIAL: All patients registered with a procedure-code for treatment of AAA in NorKar or NPR during 2001 or 2002, were included. METHOD: We compared the reporting of procedure-codes, diagnosis-codes and in-hospital deaths after treatment for abdominal aortic aneurysm (AAA) in the two registries to evaluate completeness. Consistency between procedure-codes and diagnoses were evaluated within both registries. Completeness of reporting to one NorKar Local Registry was investigated in more detail in one of the hospitals. RESULTS: Compared with the NPR numbers, NorKar contained 69% of the patients treated for AAA in Norway, while completeness for NorKar member hospitals was 84%. The detailed investigation in one of the hospitals showed a completeness of 91% and a false inclusion of 5.3% of all cases treated for AAA. The consistency between procedure-codes and diagnosis-codes was 93% in both registries. We found evidence of substantial underreporting of in-hospital deaths to NorKar in several hospitals. Overall reporting of early deaths to NorKar relative to completeness of reported cases was estimated to 72%. CONCLUSION: There is an underreporting of patients with AAA to NorKar according to the NPR numbers and a need for better control of procedure-diagnosis consistency in both registries. There seems to be a substantial underreporting of early deaths to NorKar. Introduction of unique patient-identifiable data could improve the quality of both registries by making matching of data possible.

Changes in hemodynamics and acid-base balance during cross-clamping of the descending thoracic aorta. A study in patients operated on for thoracic and thoracoabdominal aortic aneurysm.

AIM OF THE STUDY: In the clinical situation there is discrepancy between various investigations regarding the cardiac response of thoracic aortic cross-clamping. The aim was therefore to investigate the hemodynamic response and blood gases during proximal aortic cross-clamping (XC) in patients operated for descending thoracic and thoracoabdominal aortic aneurysm without circulatory support. PATIENTS AND METHODS: Altogether 51 patients operated on for thoracoabdominal (n=31) or descending thoracic aortic aneurysm (n=20) were included in the investigation. All patients were operated with aortic XC, but no circulatory support was applied. Hemodynamic variables and blood gases were recorded before and during XC. RESULTS: A significant increase in cardiac output during XC from 4.7 to 6.0 liters/min was observed (p<0.01). There was a similar percentual increase in heart rate and also the proximal systolic blood pressure increased. A metabolic acidosis occurred during XC. CONCLUSION: Cardiac output was significantly increased during XC in patients operated on for thoracoabdominal or descending thoracic aneurysm using direct aortic XC without circulatory support. Simultaneously, the heart rate was increased and there was a hyperdynamic circulatory state proximal to the aortic clamp. Redistribution of the blood volume in addition to catecholamine release may be responsible for the observed changes. These observations may influence the selection of operative strategy for some of these patients.

A strategy for treatment of type III and IV thoracoabdominal aortic aneurysm.

The aim of this study was to describe the results of resection and graft replacement for type III and IV thoracoabdominal aortic aneurysm repair. In this retrospective study, 27 patients underwent resection and graft replacement for type III (10) or type IV (17) thoracoabdominal aortic aneurysms. Nine patients had rupture, 12 were symptomatic, and 6 were operated on electively. The "clamp-and-sew" technique was applied in six cases. In 12 patients with type IV aneurysm the proximal part of the vascular graft was beveled, including the orifices of the celiac, superior mesenteric, and one or both renal arteries in the proximal anastomosis. Finally, eight patients underwent surgical application of a shunt for perfusion of the celiac and superior mesenteric arteries. One patient was treated with a combination of open and endovascular surgery. There were four early deaths (14.8%), all following operations for rupture, which represents a 45% mortality rate in this subgroup of patients. Two patients with type III aneurysm had postoperative paraparesis. One was symptomatic whereas the other was operated on electively. Excluding the patients with rupture, the accumulated 5-year survival rate was 65%. These results indicate that direct cross-clamping of the aorta gives limited time for performing the necessary anastomoses without inducing mesenteric ischemia. Inclusion of the orifices of the visceral arteries in the upper anastomosis is a feasible method during surgery for type IV aneurysms. Finally, shunting of the celiac and the superior mesenteric arteries seems to be useful, especially during surgery for type III aneurysms.

Shunting of the coeliac and superior mesenteric arteries during thoracoabdominal aneurysm repair.

OBJECTIVES: To describe our experience with shunting of the coeliac and superior mesenteric arteries during thoracoabdominal aneurysm repair. DESIGN: Retrospective study. MATERIAL: Eight patients undergoing resection and graft replacement of Crawford type III (5) and type IV (3) thoracoabdominal aortic aneurysms were included in this series. One patient had rupture, four were symptomatic and three were operated on electively. METHODS: A vascular graft with a sidearm was applied for the reconstructions. A T-shunt was connected to the sidearm. Following completion of the proximal anastomosis the shunt was inserted into the coeliac and superior mesenteric arteries. The anastomoses to these arteries and the renal arteries were then completed. Finally the distal anastomosis was performed. RESULTS: There was no early mortality (30 days). One patient had postoperative paraparesis, but recovered quite well. Reoperation became necessary due to sigmoid necrosis in one patient and due to haemorrhage in another. During the follow-up period four patients died but the other patients are alive between 3 and 8 years after surgery. CONCLUSION: The application of shunting of the superior mesenteric and coeliac arteries during thoracoabdominal aortic surgery is feasible and the results have been acceptable. Further investigation of the optimal blood flow needed to avoid intestinal ischaemia in a larger series of patients is desirable.

Inflammatory aortic aneurysm is associated with increased incidence of autoimmune disease.

OBJECTIVE: It has been suggested that certain genetic risk factors indicative of an autoimmune mechanism can be identified in patients with inflammatory aortic aneurysm (IAA). We therefore investigated whether there was a higher incidence of autoimmune diseases in patients with IAA. Further, we explored risk factors, need for in-hospital resources, and early results of treatment, in a case-control study in a university hospital setting. Material and methods From 1983 to 1994, 520 patients were operated because of abdominal aortic aneurysm (AAA). Thirty-one patients had IAA. Control subjects were matched for aneurysm rupture, emergency or elective hospital admission, and date of operation. Two noninflammatory AAA were included for every IAA. RESULTS: Of the 31 patients with IAA, 6 patients (19%) had autoimmune disease, compared with none of the control subjects (P =.0017). Two patients had rheumatoid arthritis, 2 patients had systemic lupus erythematosus, 1 had giant cell arteritis, and 1 patient had an undifferentiated seronegative polyarthritis diagnosed as rheumatoid arthritis. Nineteen patients (61%) with IAA had involvement of the duodenum, and 8 patients (26%) had hydronephrosis with ureteral involvement. Operating time was longer in the IAA group, which also had a higher need for blood transfusion. Hospital stay, intensive care unit stay, and 30-day mortality were similar in the two groups. CONCLUSION: Except for longer operating time and more need for blood transfusions in the IAA group, use of hospital resources was similar after operations to treat IAA or noninflammatory AAA. The study findings indicate an association between IAA and autoimmune disease. This is in accordance with other reports that showed a genetic risk determinant mapped to the human leukocyte antigen (HLA) molecule in these patients. Further research is necessary to explore whether IAA might be a separate entity with a role of antigen binding in the origin of the disease.

Universal or selective screening of the neonatal hip using ultrasound? A prospective, randomised trial of 15,529 newborn infants.

The aim of this study was to evaluate whether universal (all neonates) or selective (neonates belonging to the risk groups) ultrasound screening of the hips should be recommended at birth. We carried out a prospective, randomised trial between 1988 and 1992, including all newborn infants at our hospital. A total of 15 529 infants was randomised to either clinical screening and ultrasound examination of all hips or clinical screening of all hips and ultrasound examination only of those at risk. The effect of the screening was assessed by the rate of late detection of congenital or developmental hip dysplasia in the two groups. During follow-up of between six and 11 years, only one late-detected hip dysplasia was seen in the universal group, compared with five in the subjective group, representing a rate of 0.13 and 0.65 per 1,000, respectively. The difference in late detection between the two groups was not statistically significant (p = 0.22). When clinical screening is of high quality, as in our study, the effect of an additional ultrasound examination, measured as late-presenting hip dysplasia, is marginal. Under such circumstances, we consider that universal ultrasound screening is not necessary, but recommend selective ultrasound screening for neonates with abnormal or suspicious clinical findings and those with risk factors for hip dysplasia.

Spinal cord metabolism during thoracic aortic cross-clamping in pigs with special reference to the effect of allopurinol.

OBJECTIVE: investigate the metabolic response of the spinal cord and the effect of allopurinol following cross clamping of the descending thoracic aorta in a porcine model. DESIGN: experimental animal study. MATERIALS: twelve domestic swine. Six pigs were pre-treated with allopurinol, while six pigs served as controls. METHODS: measurement of extracellular concentrations of glucose, pyruvate, lactate, glycerol and glutamate using microdialysis in the lumbar spinal cord. Measurement of lumbar spinal blood flow using laser Doppler technique. RESULTS: for all animals there was a significant decrease in concentrations of glucose and pyruvate together with a significant increase in the lactate-pyruvate ratio during aortic cross clamping. There was also a significant increase in glycerol concentrations 60 min after cross clamping, and a significant decrease in glutamate concentrations after 50 min. No differences in concentrations of glucose, pyruvate, lactate and glutamate or the glutamate-pyruvate ratio were observed between animals used as controls and those treated with allopurinol. The laser Doppler flux decreased to 40% of pre cross-clamp level, returning to normal values at declamping. CONCLUSION: the changes in energy-related metabolites reflect a considerable ischaemia in the spinal cord tissue but there was no convincing effect of allopurinol on the lumbar spinal cord metabolism during thoracic aortic cross clamping in this model.

Microdialysis of the spinal cord during thoracic aortic cross-clamping in a porcine model.

OBJECTIVE: Utilising microdialysis to measure the changes of glucose, lactate, pyruvate and glutamate levels in the spinal cord after cross-clamping of the thoracic aorta in an established porcine model to monitor the degree of ischaemia. DESIGN: Experimental study with a porcine model. SETTING: University Hospital, Trondheim. SUBJECTS: Six pigs. MAIN OUTCOME MEASURE: Lactate, pyruvate and glutamate concentrations in the microdialysis perfusate from the spinal cord. RESULTS: A significant increase of the lactate-pyruvate ratio during the last 30 min of the 1 h clamping period, with a maximum increase of 169% from the basal value the last 10 min before declamping. No evident change in this ratio between the clamping and the reperfusion period. No significant change in glutamate levels during clamping or reperfusion period. CONCLUSION: Microdialysis reflects the ischaemic state of the spinal cord during cross-clamping of the thoracic aorta in pigs, and is well suited to study each phenomena.

Cardiac output measurements during cross-clamping of the descending thoracic aorta in pigs. A comparison between transit-time ultrasound, thermodilution and pulsed Doppler ultrasound.

BACKGROUND: Cross-clamping of the descending thoracic aorta (XC) induces an increase in cardiac output (CO). The intention of this study was to evaluate the high CO during XC by the use of clinically available methods (thermodilution and pulsed Doppler ultrasound) compared to transit-time ultrasound flowmetry of the ascending aorta as the gold standard. METHOD: Ten pigs were anaesthetised with ketamine and fentanyl. The descending thoracic aorta was cross-clamped for 30 min, and cardiac output was measured with pulmonary artery thermodilution technique, pulsed Doppler ultrasound on the aortic annulus and transit-time ultrasound flowmetry of the ascending aorta. RESULTS: At 15 min following XC, CO increased from 1.7 l/min to 4.6 l/min measured with transit-time ultrasound (P<0.05). With thermodilution technique, CO increased from 2.6ll/min to 5.7 l/min (P<0.05), and from 2.4 l/min to 6.0 l/min measured with Doppler ultrasound (P<0.05). There was an increase in mean arterial pressure of 81% and heart rate increased 76% (P<0.05). CONCLUSION: XC of the descending thoracic aorta induces an increase in CO of 171%. Thermodilution and pulsed Doppler ultrasound are reliable methods for detecting high cardiac output during thoracic aortic surgery.

[Endovascular treatment of thoracic aortic aneurysm]. / Endovaskulaer behandling av torakale aortaaneurismer.

Two patients with aneurysms of the descending thoracic aorta were treated by endovascular technique. One of the patients was also treated for an infrarenal aortic aneurysm by open surgery during the same procedure. The other patient had chest pain, probably caused by an impending rupture. The procedures were performed using fluoroscopy by a C-arm. The thoracic aneurysms were replaced by an implant made of polyester where Z-stents had been applied on the inside. The prosthesis was mounted on a pusher and advanced through an introducer. When a proper position was obtained, the introducer was withdrawn, and the prosthesis was deployed immediately below the left subclavian artery. Endovascular treatment seems to represent a less traumatic procedure than open surgery. Both operations were uncomplicated and both patients were followed up for more than six months. No complications were observed. A longer follow-up period is necessary to evaluate this treatment fully.

Chylous complications after abdominal aortic surgery.

Two patients developed chylous complications following abdominal aortic aneurysm repair. One patient had chylous ascitis and was successfully treated by a peritoneo-caval shunt. The other patient developed a lymph cyst, which gradually resorbed after puncture. Chylous complications following aortic surgery are rare. Patients in bad a general condition should be treated by initial paracentesis and total parenteral nutrition, supplemented by medium-chain triglyceride and low-fat diet. If no improvement is observed on this regimen, the next step should be implementation of a peritoneo-venous shunt, whereas direct ligation of the leak should be reserved for those who are not responding to this treatment.

Ultrasound imaging during endovascular abdominal aortic aneurysm repair using the Stentor bifurcated endograft.

PURPOSE: To evaluate different ultrasound modalities during implantation and follow-up of endovascular grafts for abdominal aortic aneurysm (AAA) exclusion. METHODS: Between February 1995 and May 1996, 18 patients (14 men; aged 49 to 80 years, mean 67) were treated with endovascular intervention for infrarenal AAA. Seventeen patients received Mialhe Stentor bifurcated grafts, while one patient was treated with a straight graft for pseudoaneurysm. During and after the implantation, 3.25- and 5-MHz annular array ultrasound probes were used for transabdominal visualization of the endograft. Intravascular ultrasound was applied in combination with angiography for postoperative control. RESULTS: Intraprocedurally, transabdominal two-dimensional (2D) ultrasound successfully monitored guidewire passage from the groin into the main part of the bifurcated endograft for implantation of the second limb. All implantation procedures were technically successful, but four endoleaks were identified intraprocedurally by 2D ultrasound and angiography. One healed spontaneously, two were treated with endovascular techniques at 1 and 4 months, and the last leak was scheduled for repair when the patient died of probable myocardial infarction at 2 months. During follow-up, 2D ultrasound successfully visualized all the endografts; no endoleaks were found in up to 18 months of surveillance. CONCLUSIONS: Transabdominal ultrasound imaging could be valuable in bifurcated endograft deployment both for guiding guidewire insertion and for controlling wire position before the second graft limb is connected to the main graft. Provided that satisfactory visualization of the entire endograft can be obtained, ultrasound examination may possibly replace arteriography and computed tomographic scanning as a follow-up investigation.

The importance of transesophageal echocardiography during surgery of the thoracic aorta.

OBJECTIVES: To assess left ventricular dimensions and cardiac output during thoracic and thoracoabdominal aortic aneurysm repair. MATERIAL AND METHODS: Nine patients undergoing thoracic and thoracoabdominal aneurysm repair using direct cross-clamping without shunt or by-pass were studied prospectively. Prior to, during cross-clamping (XC) and after declamping left ventricular cross-sectional areas were monitored with transesophageal echocardiography. A pulmonary artery catheter was used for measurements of cardiac output with the thermodilution technique. RESULTS: Cardiac output increased 43% from baseline during XC (p < 0.01) and was still 55% above baseline at declamping (p < 0.05). Left ventricular end-systolic inner area was reduced 32% during XC (p < 0.01). Pulmonary artery pressures and central venous pressure increased during declamping (p < 0.05). Heart rate increased 38% from 66 beats/ min to 92 beats/min (p < 0.01) and was still 30% elevated at declamping (p < 0.01). CONCLUSION: During thoracic aortic XC, cardiac output is increased and left ventricular end-systolic dimension is reduced. TEE is a valuable supplement to pressure measurements for the evaluation of cardiac function during surgery of the thoracic aorta.

Selective carotid angiography during cross-clamping of the descending thoracic aorta in pigs.

OBJECTIVE: To visualize the intra- and extracranial blood vessels during cross-clamping of the descending thoracic aorta. EXPERIMENTAL DESIGN: Experimental animal study. SETTING: Animal laboratory, University Hospital. MATERIALS: Seven pigs. INTERVENTIONS: Cross-clamping of the descending thoracic aorta for 30 minutes. METHOD: Selective carotid angiography was performed before, during and after cross-clamping. Venous filling time of internal- and external jugular veins, diameter of internal and external jugular veins and internal, external and common carotid arteries and contrast intensity were determined. RESULTS: During cross-clamping the blood flow velocity increased as demonstrated by decreased venous filling time and decreased contrast intensity. In addition, the diameter of the external jugular vein increased and the diameter of the internal carotid artery decreased during cross-clamping. No arteriovenous anastomoses could be detected during the experiment. CONCLUSIONS: Our results indicate increased intra- and extracranial blood flow during cross-clamping of the descending thoracic aorta in pigs.

Cerebral haemodynamics during thoracic- and thoracoabdominal aortic aneurysm repair.

OBJECTIVE: To investigate cerebral haemodynamics during operations for thoracic and thoracoabdominal aortic aneurysms. DESIGN: Prospective clinical study. MATERIAL: 10 patients operated on consecutively with resection for thoracic (5) or thoracoabdominal aortic (5) aneurysms. METHODS: Blood flow velocity of the middle cerebral artery was measured through a temporal approach using a TC Doppler with a 2 MHz probe. Recordings were made during induction of anaesthesia and performed continuously before, during and after cross-clamping of the aorta. RESULTS: Following 10 min. of aortic cross-clamping blood flow velocity of the middle cerebral artery increased from 44 to 55 cm/s (p < 0.01). A further increase to 69 cm/s (p < 0.01) was observed 5 min after declamping. The pulsatility index averaged 0.74 increasing to 1.21 (p < 0.05) at clamping and 0.87 (p < 0.05) after declamping. CONCLUSION: There was an increased blood flow velocity of the middle cerebral artery during cross-clamping of the descending thoracic aorta in patients operated on for thoracic and thoracoabdominal aortic aneurysms. This increase in cerebral blood flow and blood volume could explain the acute increase in cerebrospinal fluid pressure observed during cross-clamping of the thoracic aorta.

Effect of sodium nitroprusside on cerebral haemodynamics during cross-clamping of the descending thoracic aorta in pigs.

OBJECTIVE: To assess the effect of sodium nitroprusside on cerebral haemodynamics during cross-clamping of the descending thoracic aorta in pigs. DESIGN: Non-randomised controlled animal study. SETTING: University hospital, Norway. MATERIAL: 17 Pigs. INTERVENTIONS: Cross-clamping of the descending thoracic aorta for 30 minutes. In 8 pigs sodium nitroprusside was given to prevent proximal hypertension (sodium nitroprusside group); 9 pigs were given no sodium nitroprusside (control group). MAIN OUTCOME MEASURES: Intracerebral pressure, sagittal sinus pressure, cerebral flux, and internal carotid artery blood flow. RESULTS: Intracerebral pressure, sagittal sinus pressure, and cerebral flux increased in both groups during cross-clamping of the descending thoracic aorta. There were no differences between the groups in these variables despite significantly lower mean proximal aortic pressure in the sodium nitroprusside group. CONCLUSIONS: Sodium nitroprusside did not affect intracerebral pressure, sagittal sinus pressure, or cerebral flux during cross-clamping of the descending thoracic aorta. Increased cerebral blood flow rather than venous congestion is the most likely cause of increased intracranial pressure during cross-clamping of the descending thoracic aorta.

[Results after surgical treatment of abdominal aortic aneurysm]. / Resultater etter kirurgisk behandling av abdominale aortaaneurismer.

During the period 1983-1993 altogether 403 patients were operated on for abdominal aortic aneurysm. The median age was 69.5 years. 246 were operated on electively whereas 58 had symptoms without rupture and 99 had ruptured aneurysm. The 30 day mortality in the three groups was 4.1, 12.0 and 28.3% respectively. The mortality in hospital was 4.5, 12.0 and 31.3% in the three groups respectively. Coronary artery disease dominated as cause of death in the group as a whole, whereas irreversible shock and complications secondary to haemorrhage were common in the group with ruptured aneurysm. There were no graft infections in this series, and only one superficial infection which healed without complications. Investigation and treatment of coronary artery disease might perhaps decrease the mortality rate in the elective group. These results form a basis against which the results of endovascular treatment should be compared.

[Endovascular treatment of abdominal aortic aneurysms]. / Endovaskulaer behandling av abdominale aortaaneurismer.

Eight patients, six men and two women (mean age 67.3 years) were treated for infrarenal abdominal aortic aneurysm by endovascular technique. A bifurcated graft (Mialhe Stentor, Min Tec, France) was used in all cases. The introducing system, with an 18 French diameter, is inserted through an arteriotomy in the common femoral artery. The proximal end of the main part of the graft is placed just distal to the renal arteries, and includes one graft limb, which is placed in the iliac artery on the ipsilateral side. The contralateral graft limb is introduced into a short limb of the main graft through a 10 French introducer, using Seldinger-technique, from the contralateral common femoral artery. All the implantations were successful from both a technical and a clinical point of view. All patients except one were mobilized on the first day after operation and received a normal diet. A thorough preoperative evaluation of the patient with regard to selection of the right size of the implant is necessary, and the implantation must be performed with great attention to technical details.

Lymph drainage and the development of post-reconstructive leg oedema is not influenced by the type of inguinal incision. A prospective randomised study in patients undergoing femoropopliteal bypass surgery.

OBJECTIVES: To see whether the type of groin incision influenced the degree of postoperative leg oedema and the occurrence of lymphatic damage. DESIGN: Prospective randomised clinical study. SETTING: University Department of Surgery. MATERIALS: Twenty-four patients undergoing femoropopliteal bypass reconstruction with either a lateral groin incision (Group A, n = 12) or a direct incision over the femoral vessels (Group B, (n = 12). CHIEF OUTCOME MEASURES: The leg volume increase was measured according to the formula of a truncated cone. Deep venous thrombosis was excluded by air plethysmography and colour-coded Duplex scanning. Lymphatic lesions were detected by lymphoscintigraphy using 99mTc labelled human serum albumin. MAIN RESULTS: One week following vascular reconstruction the median leg volume increase was 24.5% in Group A vs. 23.3% in Group B (NS). Lymphoscintigraphy revealed obstruction of the lymphatics in five patients of Group A vs. three patients of Group B (NS). Neither the occurrence of lymph cysts nor extravasation of lymph differed between the two groups. In seven patients no lymphatic lesion was observed. Patients with interruption of the lymphatics (n = 8) had a higher leg volume increase compared to the remaining patients with no or minor lymphatic lesions, 31.2% vs. 19.6%, respectively (p < 0.05). CONCLUSIONS: Leg oedema and the occurrence of lymphatic damage following femoropopliteal bypass surgery is not reduced by applying a lateral approach to the femoral artery in the groin. However, the higher leg volume increase in patients with lymphatic obstruction indicates that lymphatic damage could play a part in the leg oedema formation.