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PREVENTION OF DAMAGE TO THE URETER AND BLADDER DURING HYSTERECTOMY
638 AUTOIMMUNITY SIR The implications of the mathematical theory of autoimmunity proposed by Dr. Burch and Dr. Rowell (Sept. 7) should not be taken seriously. If they care to plot the age-incidence versus age for female puberty and the menopause, they will find that the curves fit their general equation (1) fairly well. I leave them to calculate the value of r for these conditions-that is, how many somatic mutations it takes to cause puberty and the menopause. Are we seriously to believe that these common occurrences are the result of somatic mutation; and that only a small proportion of girls are born with the risk of undergoing puberty and the menopause ? GEOFFREY E. LOXTON. PARATHYROID INSUFFICIENCY
SIR,-In their letters of Aug. 24
on the subject of after thyroidectomy, your corparathyroid insufficiency respondents suggested that the discrepancy between the findings of Dr. Harvard Davis and his colleaguesin Cardiff and Dr. Rose2 at University College Hospital might be due to differences in surgical technique at the two centres-namely, identification of the recurrent laryngeal nerves and ligation of the trunk of the inferior thyroid arteries at operation.
advocate of routine identification of the recurrent thyroidectomy, I have always beehBconcerned that this practice might endanger the parathyroid glands, and I discussed this possibility with Dr. Harvard Davis after his investigations were completed. He told me that approximately 75% of the patients in the series had been operated on by surgeons who did not practise nerve identification, and that the incidence of postoperative parathyroid insufficiency was almost identical whether operation had been performed by a surgeon who identified the nerve routinely or by one who did not. These facts were not included in the published results, but I did mention them in a paper read at the Royal Society of Medicine in 1961.3 With regard to ligation of the trunk of the inferior thyroid artery, as opposed to its glandular branches, there are no precise figures from this series. This problem was, however, subsequently studied by Dr. Jones and Dr. Fourman,4when they investigated 46 patients who had had a thyroidectomy performed by members of the staff of the professorial surgical unit at the Cardiff Royal Infirmary. The accepted practice on the unit was to ligate the glandular branches of the inferior thyroid arteries and not the proximal trunks, and also, incidentally, not to identify the recurrent nerves. Their figure of 28% for the incidence of postoperative parathyroid insufficiency is comparable with that of 24% reported in the other Cardiff series. Such evidence as we have does not, therefore, lend any support to the suggestion that either recurrent nerve identification, or proximal ligation of the inferior thyroid artery, is responsible for the dissimilar results reported from Cardiff and from University College Hospital. Nevertheless, I think that Mr. John and Dr. Wills have done well to reopen the discussion on recurrent nerve identification in this context. The possibility of injury to the parathyroid glands, -during such dissection as is necessary, is the only valid argument that has so far been advanced against a procedure which, in my opinion, greatly reduces the risk of permanent recurrent nerve paralysis, as opposed to transient nerve paralysis. I should be prepared to reconsider my practice of routine nerve identification only if I felt that it was responsible for an unacceptable rate of postoperative parathyroid insufficiency. At present I know of no evidence that this is so. 1. Davis, R. H., Fourman, P., Smith, J. W. G. Lancet, 1961, ii, 1432. As
an
nerves at
2. 3. 4.
Rose, N. ibid. July 20, 1963, p. 116. Wade, J. S. H. Proc. R. Soc. Med. 1961, 54, 875. Jones, K. H., Fourman, P. Lancet, July 20, 1963, p. 121.
becoming increasingly clear that parathyroid insufficiency after thyroidectomy is caused principally by damage to the blood-supply of the parathyroid glands, and that accidental removal of parathyroid tissue, so aptly termed inadvertent parathyroidectomy ",5 is a relatively unimportIt is
"
factor. However, I cannot accept Mr. Keynes’s suggestion that damage to the parathyroid blood-supply may be due to proximal ligation of the inferior thyroid artery. The parathyroid arteries are end arteries, arising from glandular branches of the inferior thyroid artery. The anastomoses between these glandular branches and oesophageal and tracheal arteries are so extensive that infarction of the gland will occur only if the parathyroid artery itself is damaged. It is immaterial, therefore, whether the main trunk of the inferior thyroid artery, or its glandular branches, are ligated, provided that sutures and ligatures are not placed close enough to the hilum of the parathyroid gland to damage the parathyroid artery itself. Indeed, if the inferior thyroid trunks are not ligated, the increased vascularity of the thyroid remnants will require more extensive haemostatis and the risk of damage to the parathyroid blood-supply will actually be increased.
ant
There
several points in surgical technique at thyroidectomy which may help to protect the parathyroid glands, not the least of which is an adequate exposure of the operative field. But the most important point, in my opinion, is the careful inspection of the mobilised goitre before resection, and particularly of the sites where parathyroid glands are usually to be found. Any structure which can be identified as a parathyroid gland, or which resembles parathyroid tissue, should be preserved, and no ligature or suture should be placed close to it if this can possibly be avoided. In this connection I feel that deliberate dissection to identify parathyroid glands is unjustified. When operating on a parathyroid adenoma the surgeon is usually dealing with a normal thyroid gland, but at thyroidectomy the increased vascularity and distorted anatomy associated with most goitres constitute an unacceptable risk to the parathyroid arteries. May I add that I do not consider this attitude to be inconsistent with my views on recurrent nerve identification. are
’
United Cardiff Hospitals.
J.
S. H. WADE.
PREVENTION OF DAMAGE TO THE URETER AND BLADDER DURING HYSTERECTOMY
SIR,-It comes as a surprise to read of the technique advocated by Dr. Palocz (Sept. 7) in order to identify the ureters during a difficult hysterectomy. Apart from the exposure of a patient to unnecessary radioactivity, and the expense of buying the appropriate detector, why not do the simple preliminary procedure of a bilateral ureteric catheterisation. The catheters can then be felt in position in the ureters, during the abdominal operation. Eastbourne,
GRANT WILLIAMS.
Sussex
NAIL GROWTH IN COLD WEATHER
SIR,—Beau’s lines, the condition described by Dr. McCormick (Sept. 7), are generally associated with some general medical disturbance, such as coronary thrombosis. But they are well known to follow excessive exposure to cold in persons who have cold extremities. I saw many cases in the past few months after the severe cold of last winter. The main difference between Beau’s lines due to cold and those due to a general disorder is that in the former some nails may be spared or may be less severely affected 5.
Murley,
R.
S., Peters, R. M. Proc. R. Soc. Med. 1961, 54, 487.
SIR,-In their letters of Aug. 24
on the subject of after thyroidectomy, your corparathyroid insufficiency respondents suggested that the discrepancy between the findings of Dr. Harvard Davis and his colleaguesin Cardiff and Dr. Rose2 at University College Hospital might be due to differences in surgical technique at the two centres-namely, identification of the recurrent laryngeal nerves and ligation of the trunk of the inferior thyroid arteries at operation.
advocate of routine identification of the recurrent thyroidectomy, I have always beehBconcerned that this practice might endanger the parathyroid glands, and I discussed this possibility with Dr. Harvard Davis after his investigations were completed. He told me that approximately 75% of the patients in the series had been operated on by surgeons who did not practise nerve identification, and that the incidence of postoperative parathyroid insufficiency was almost identical whether operation had been performed by a surgeon who identified the nerve routinely or by one who did not. These facts were not included in the published results, but I did mention them in a paper read at the Royal Society of Medicine in 1961.3 With regard to ligation of the trunk of the inferior thyroid artery, as opposed to its glandular branches, there are no precise figures from this series. This problem was, however, subsequently studied by Dr. Jones and Dr. Fourman,4when they investigated 46 patients who had had a thyroidectomy performed by members of the staff of the professorial surgical unit at the Cardiff Royal Infirmary. The accepted practice on the unit was to ligate the glandular branches of the inferior thyroid arteries and not the proximal trunks, and also, incidentally, not to identify the recurrent nerves. Their figure of 28% for the incidence of postoperative parathyroid insufficiency is comparable with that of 24% reported in the other Cardiff series. Such evidence as we have does not, therefore, lend any support to the suggestion that either recurrent nerve identification, or proximal ligation of the inferior thyroid artery, is responsible for the dissimilar results reported from Cardiff and from University College Hospital. Nevertheless, I think that Mr. John and Dr. Wills have done well to reopen the discussion on recurrent nerve identification in this context. The possibility of injury to the parathyroid glands, -during such dissection as is necessary, is the only valid argument that has so far been advanced against a procedure which, in my opinion, greatly reduces the risk of permanent recurrent nerve paralysis, as opposed to transient nerve paralysis. I should be prepared to reconsider my practice of routine nerve identification only if I felt that it was responsible for an unacceptable rate of postoperative parathyroid insufficiency. At present I know of no evidence that this is so. 1. Davis, R. H., Fourman, P., Smith, J. W. G. Lancet, 1961, ii, 1432. As
an
nerves at
2. 3. 4.
Rose, N. ibid. July 20, 1963, p. 116. Wade, J. S. H. Proc. R. Soc. Med. 1961, 54, 875. Jones, K. H., Fourman, P. Lancet, July 20, 1963, p. 121.
becoming increasingly clear that parathyroid insufficiency after thyroidectomy is caused principally by damage to the blood-supply of the parathyroid glands, and that accidental removal of parathyroid tissue, so aptly termed inadvertent parathyroidectomy ",5 is a relatively unimportIt is
"
factor. However, I cannot accept Mr. Keynes’s suggestion that damage to the parathyroid blood-supply may be due to proximal ligation of the inferior thyroid artery. The parathyroid arteries are end arteries, arising from glandular branches of the inferior thyroid artery. The anastomoses between these glandular branches and oesophageal and tracheal arteries are so extensive that infarction of the gland will occur only if the parathyroid artery itself is damaged. It is immaterial, therefore, whether the main trunk of the inferior thyroid artery, or its glandular branches, are ligated, provided that sutures and ligatures are not placed close enough to the hilum of the parathyroid gland to damage the parathyroid artery itself. Indeed, if the inferior thyroid trunks are not ligated, the increased vascularity of the thyroid remnants will require more extensive haemostatis and the risk of damage to the parathyroid blood-supply will actually be increased.
ant
There
several points in surgical technique at thyroidectomy which may help to protect the parathyroid glands, not the least of which is an adequate exposure of the operative field. But the most important point, in my opinion, is the careful inspection of the mobilised goitre before resection, and particularly of the sites where parathyroid glands are usually to be found. Any structure which can be identified as a parathyroid gland, or which resembles parathyroid tissue, should be preserved, and no ligature or suture should be placed close to it if this can possibly be avoided. In this connection I feel that deliberate dissection to identify parathyroid glands is unjustified. When operating on a parathyroid adenoma the surgeon is usually dealing with a normal thyroid gland, but at thyroidectomy the increased vascularity and distorted anatomy associated with most goitres constitute an unacceptable risk to the parathyroid arteries. May I add that I do not consider this attitude to be inconsistent with my views on recurrent nerve identification. are
’
United Cardiff Hospitals.
J.
S. H. WADE.
PREVENTION OF DAMAGE TO THE URETER AND BLADDER DURING HYSTERECTOMY
SIR,-It comes as a surprise to read of the technique advocated by Dr. Palocz (Sept. 7) in order to identify the ureters during a difficult hysterectomy. Apart from the exposure of a patient to unnecessary radioactivity, and the expense of buying the appropriate detector, why not do the simple preliminary procedure of a bilateral ureteric catheterisation. The catheters can then be felt in position in the ureters, during the abdominal operation. Eastbourne,
GRANT WILLIAMS.
Sussex
NAIL GROWTH IN COLD WEATHER
SIR,—Beau’s lines, the condition described by Dr. McCormick (Sept. 7), are generally associated with some general medical disturbance, such as coronary thrombosis. But they are well known to follow excessive exposure to cold in persons who have cold extremities. I saw many cases in the past few months after the severe cold of last winter. The main difference between Beau’s lines due to cold and those due to a general disorder is that in the former some nails may be spared or may be less severely affected 5.
Murley,
R.
S., Peters, R. M. Proc. R. Soc. Med. 1961, 54, 487.