Intra-Operative Parathyroid Hormone Assay for Simplified Localization of Parathyroid Adenomas

Lack of success in parathyroid surgery is usually due to failure to identify the abnormal parathyroid gland correctly at operation. The surgeon may be helped by rapid parathyroid hormone (PTH) assay in peripheral blood after removal of a suspected adenoma, and by frozen section histology, but these are not true localization techniques. We have adapted a non-isotopic immunoassay for rapid measurement of PTH in samples from the upper, middle and lower thyroid veins taken at operation, before exploration begins. Fifteen patients with primary hyperparathyroidism were operated on. In 10 the parathyroid adenoma was located easily, and was associated with high local venous PTH levels. In four patients the abnormal parathyroid was not immediately apparent but the assay indicated its location, which was confirmed after further exploration. In one patient there was no difference in PTH levels in the six venous samples. An ectopic adenomatous gland was successfully identified behind the thymus. The operation was successful in all patients as shown by a fall in the plasma calcium to the normal range. We conclude that intra-operative selective venous sampling and rapid PTH assay facilitates operative localization of parathyroid adenomas.

Patterns, timing and consequences of post-thyroidectomy haemorrhage

INTRODUCTION Post-thyroidectomy bleeding is a low frequency but potentially life threatening event that is very difficult to predict. Given the increasing drive towards thyroidectomy with same day discharge, this study was conducted with the aim of identifying patterns, timing and consequences of post-thyroidectomy bleeding to assess the feasibility of day-case thyroidectomy. METHODS All patients who underwent a thyroidectomy between 2008 and 2015 at our institution were identified. Patterns, timing and consequences in all those who developed post-thyroidectomy bleeding were studied. RESULTS Of the 805 patients included in the study, 14 required re-exploration for bleeding; 7 (50%) of these within 8 hours of surgery, 6 (43%) between 18 and 30 hours, and 1 (7%) at 49 hours. Just under half (43%) of those with post-thyroidectomy bleeding had thyrotoxicosis. CONCLUSIONS A significant number of postoperative haemorrhages occurred beyond the immediate postoperative period. Same day discharge after thyroidectomy cannot therefore be recommended as a routine practice.

Neutrophil CD11b Expression in Patients with Venous Disease

Objective:

To determine whether neutrophil CD11b, a marker of neutrophil adhesion, differs in patients with varying degrees of severity of venous disease, and to compare the values obtained with those of age-matched normal control subjects.

Design:

Prospective study, measuring white cell count and neutrophil CD11b expression in whole blood using a fluorescent-labelled monoclonal antibody in a flow cytometer.

Setting:

The Middlesex Hospital Vascular Laboratory, a referral centre for the investigation of venous disease.

Patients:

Ten patients with uncomplicated varicose veins, 10 patients with skin changes of lipodermatosclerosis (LDS), and 20 age-matched control subjects with no history or clinical finding of venous disease.

Results:

Higher levels of CD11b were found in patients with uncomplicated varicose veins compared with their controls (median 4.6 cf. 1.43 for normal controls, P = 0.005, Mann-Whitney U-test, difference between medians 2.7, 95% confidence interval 1 to 4.6), and lower levels in patients with LDS (median 1.22 cf. 1.53 for normal controls, p = 0.028, Mann-Whitney U-test, difference between medians 0.45, 95% confidence interval 0.02 to 1.3). There was no difference in the white cell or neutrophil count between the patient and control groups.

Conclusions:

This study demonstrates increased neutrophil surface CD11b expression in patients with uncomplicated varicose veins, but decreased levels in patients with LDS. This might be due to up-regulation of CD11b in some neutrophils with subsequent adhesion, so that only those with low expression remained in the peripheral circulation. Alternatively, this might represent either down-regulation or chronic exhaustion of neutrophil CD11b in these patients.

Objective Assessment of Skin Changes in Lower Limb Venous Disease Using a Tissue Tonometer

Background:

Chronic venous disease (CVD) of the lower limbs is a major problem in the western world with 1% of the adult population estimated to be affected at any one time. No objective method is currently available to assess the skin changes of chronic venous disease. We have devised a tissue tonometer to compare skin compliance in patients with venous disease with that in control subjects.

Method:

Eighty-six limbs of 69 patients (34 men, 35 women; mean age 62 years, range 28-90 years) with venous disease confirmed by duplex ultrasonography and 42 limbs of 37 normal controls (23 men, 14 women; mean age 42 years, range 20-90 years) were studied. Patients were assigned to one of three clinical groups based on the Clinical, (a) Etiological, Anatomical and Pathophysiological (CEAP) method of classification and grading of chronic venous disease in the lower limbs: C3, oedema; C4a, pigmentation alone; C4b, lipodermato-sclerosis (LDS). Normal controls were assigned C0. A 4 mm diameter plunger loaded with a 30 g weight was applied to the skin 5 cm proximal to the medial malleolus or over the most severe region of skin change. The movement of the plunger was measured for 5 min using a linear variable differential transformer position detector. The initial displacement of the plunger (within 1 s) reflects the compliance of the skin.

Results:

In C4b patients with LDS, skin compliance is substantially reduced (median plunger displacement in 1 s = 0.81 mm, interquartile range (IQR) 0.67–1.18) compared with C0 control subjects (2.85 mm, IQR 2.39–3.22) (p<0.0005, Mann-Whitney), C4a patients with pigmentation alone without LDS (2.35 mm, IQR 2.04–2.91) (p<0.0005, Mann-Whitney) or C3 patients with venous disease (2.49 mm, IQR 1.58–3.13) (p<0.0005, Mann-Whitney). There were no statistically significant differences between the C0, C3 and C4a groups.

Conclusion:

Tissue tonometry provides an objective means of assessing skin changes in patients with lower limb chronic venous disease. This may be a useful method of measuring skin compliance as a research tool but will have limited clinical application.

Variable venous anatomy of the popliteal fossa demonstrated by duplex scanning

BACKGROUND

Location of the sapheno-popliteal junction (SPJ) is highly variable and therefore often difficult to identify correctly at operation. The anatomy is often complicated by associated pathology in the popliteal fossa, which makes clinical examination unreliable.

OBJECTIVE

The purpose of our study was to quantify this variability and record other concomitant pathology in patients with sapheno-popliteal junction incompetence.

METHODS

We retrospectively reviewed duplex scans of 544 patients with 638 legs showing SPJ incompetence, from a total of approximately 4000 patients attending our laboratory between August 1993 and August 1995.

RESULTS

We found that 51% of sapheno-popliteal junctions were located within 2 cm above the popliteal skin crease and a further 36% within 4 cm, with the remaining situated anywhere between 4 and 10 cm above the popliteal skin crease. Additionally 18% of patients had either Giacomini or gastrocnemius vein incompetence in addition to SPJ incompetence, further complicating the clinical picture.

CONCLUSION

When SPJ incompetence is suspected, duplex scanning identifies the exact location of the junction and other associated pathology in the popliteal fossa, and allows the position of the junction to be marked on the leg preoperatively.

Endothelial activation in patients with chronic venous disease

OBJECTIVES

Leukocyte trapping due to leukocyte-endothelial activation has been implicated as the cause of lipodermatosclerosis and ulceration in patients with chronic venous disease. We investigated endothelial activity in normal controls and patients subjected to short-term venous hypertension.

METHODS

Twenty-five normal volunteers and 30 patients with chronic venous disease divided into two groups: varicose veins with skin changes (LDS, n = 15); and varicose veins without skin changes (VVs, n = 15) were studied. Blood samples were taken from a foot vein before and after experimental venous hypertension. Plasma levels of ELAM-1 (endothelial leukocyte adhesion molecule-1), ICAM-1 (intercellular adhesion molecule-1), VCAM-1 (vascular cell adhesion molecule-1), and von Willebrand factor (vWf) was measured by an ELISA.

RESULTS

There was a significant rise in the plasma concentration of ELAM-1, ICAM-1 and VCAM-1 in patients and normal controls in response to venous hypertension. Basal levels of plasma VCAM-1 and vWf were higher in patients with LDS compared to patients with VVs. The magnitude of rise of VCAM-1 was greater in patients with LDS compared to patients with VVs (p = 0.01, Mann-Whitney U-test). There was no difference in the basal levels or in the magnitude of change in plasma ICAM-1 and ELAM-1 between the two patient groups.

CONCLUSION

Venous hypertension results in endothelial activation which may aid endothelial-leukocyte adhesion. Patients with LDS exhibit increased VCAM-1, which is a counterligand for receptors expressed by monocytes and lymphocytes signifying that these cells may be more important in the development of skin changes.

Leucocyte Activity in Volunteers in Response to Experimental Venous Hypertension

Objective:

To investigate leucocyte activation in normal volunteers subjected to short-term venous hypertension by measuring the cell surface expression of the integrin CD11b and the selectin CD62L on neutrophils and monocytes before and after short-term venous hypertension. Plasma levels of L-selectin, which is shed by leucocytes upon activation, were also measured.

Design:

Prospective study, measuring white cell count, neutrophil and monocyte surface CD11b and L-selectin expression in whole blood using a fluorescent-labelled monoclonal antibody in a flow cytometer, and plasma L-selectin by a commercially available ELISA.

Setting:

The Middlesex Hospital Vascular Laboratory, a referral centre for the investigation of venous diseases.

Subjects:

Twenty-five normal volunteers without any history or clinical finding of venous disease.

Results:

There was a significant fall in the white cell: red cell ratio ( p = 0.03, Wilcoxon) in response to venous hypertension, followed by a significant increase ( p < 0.001, Wilcoxon) when the venous hypertension was reversed. Neutrophil and monocyte CD11b levels fell significantly ( p < 0.001 and p < 0.001, Wilcoxon) in response to venous hypertension. On reversing the venous hypertension a significant increase of CD11b expression was noted in both neutrophils and monocytes ( p < 0.001 and p < 0.01, Wilcoxon). Surface L-selectin expression, however, showed a significant sustained fall in both neutrophils and monocytes (neutrophils, p = 0.05 and p = 0.02; monocytes, p = 0.04 and p = n.s., Wilcoxon) throughout the experiment. There was a significant rise in soluble L-selectin in the plasma following venous hypertension ( p < 0.001, Wilcoxon).

Conclusion:

This study demonstrates both neutrophil and monocyte activation in the microcirculation of normal volunteers in response to short-term venous hypertension.

Leukocyte activity in the microcirculation of the leg in patients with chronic venous disease

PURPOSE

It has been suggested that leukocyte trapping and activation in the microcirculation of the leg skin causes lipodermatosclerosis and ulceration in patients with chronic venous disease. Ambulatory venous hypertension is accepted as the physiologic factor that leads to ulceration. We investigated leukocyte endothelial adhesion in patients who were subjected to short-term venous hypertension.

METHODS

Two groups of patients with venous disease were studied: group 1, varicose veins with skin changes (n = 15); and group 2, varicose veins without skin changes (n = 15). Blood samples were taken from a foot vein before and after standing for 30 minutes to raise the venous pressure in the lower limb, and after lying supine again for 10 minutes. The samples were analyzed for leukocyte surface CD11b and L-selectin (CD62L) expression using a flow cytometer. Plasma-soluble L-selectin was also measured using an enzyme-linked immunosorbent assay.

RESULTS

In patients with skin changes, median neutrophil CD11b levels fell from 4.66 to 3.83 arbitrary units (p = 0.005, Wilcoxon) after 30 minutes of venous hypertension, Median monocyte CD11b levels fell from 7.65 to 5.8 arbitrary units (p = NS, Wilcoxon) after venous hypertension and then fell further to 5.43 arbitrary units (p = 0.02 vs baseline; Wilcoxon) when the venous hypertension was removed. Neutrophil and monocyte L-selectin levels also fell in response to venous hypertension, remaining low even after venous hypertension was removed. A similar pattern was seen in patients with uncomplicated varicose veins. There was a rise in soluble L-selectin in the plasma of both groups of patients after venous hypertension, reflecting leukocyte adhesion to endothelium. In the group of patients with skin changes the level of soluble L-selectin rose from 695 ng/ml to 836 ng/ml (p = 0.02, Wilcoxon), and in the group without skin changes the rise was from 700 ng/ml to 801 ng/ml (p = 0.02, Wilcoxon).

CONCLUSION

Venous hypertension results in sequestration of the more activated population of neutrophils and monocytes in the microcirculation of the leg in patients with venous disease. These cells bind to the endothelium, releasing L-selectin, and do not emerge from the limb when venous hypertension is reversed. These findings do not differ between patients with varicose veins and those with skin changes.

An unusual lesion of the penis

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Leukocyte migration in the leg in response to experimental venous hypertension

PURPOSE

Leukocyte trapping and activation in the microcirculation of the legs may play an important role in causing skin damage in venous disease. Leukocyte emigration from the microcirculation and subsequent locomotion in response to venous hypertension was studied in a group of 12 normal volunteers using a "skin window" technique.

METHODS

Two 0.5-cm square dermal abrasions were made with a dental stone over the gaiter area of the leg and the flexor aspect of the forearm (control), which were covered with moist micropore membranes. The volunteers lay supine for 30 minutes, and then stood supported for 30 minutes to raise the venous pressure in the leg, and then lay supine again for 30 minutes. The experiment was repeated in six volunteers who lay supine for the whole period. The membranes were changed and collected every 15 minutes, fixed in formal saline solution, and dual-stained for monocytes and polymorphonuclear leukocytes. The type and numbers of cells that emigrated and the furthest distance traveled (leading front) by the cells through the membrane were measured.

RESULTS

Both in arms and legs, the vast majority of cells that emigrated were neutrophils, with very few monocytes (arm, 93% neutrophils and 7% monocytes; leg, 97% neutrophils and 3% monocytes). In the 30 minutes after venous hypertension, leukocyte migration significantly decreased in the leg (median leukocyte locomotion: basal, 75.3 microns; standing, 73.5 microns; after hypertension, 62.9 microns; p = 0.012, Wilcoxon matched pairs signed rank test), but not in the arm (basal, 86.2 microns; standing, 84.4 microns; after hypertension, 85.5 microns; p = NS) or when the experiment was repeated with the volunteers lying supine for the entire period (basal, 91.5 microns; standing, 89.4 microns; after hypertension, 92.6 microns; p = NS).

CONCLUSIONS

Leukocyte migration is decreased immediately after experimental venous hypertension, which may be a result of the release of factors that inhibit migration.