Correspondence
Mechanism of action of external compression on venous function Sir The article on compression and venous function by Sarin et al. (Br J Surg 1992; 79: 499-502) failed to address issues raised by myself’~2and Wood3, which showed the importance of maintaining external support at precisely the same level as the intravascular pressure in all postures. Such hydrostatic stockings or ‘G’ suits theoretically compensate for postural changes. The mechanism of external support therefore does not apply solely to veins, but also to arteries and capillaries.
A. D. B. Chant Royal Souih Hants Hospital Southampton SO9 4PE UK
stumps in very low anastomosis’,’. In a prospective randomized trial currently being conducted in this department with 19 patients to date, median frequencies of bowel movement per 24 h of 2 (range 0-5) and 5 (range 2-15) were obtained for pouch-anal and straight anastomoses respectively 1 month after ileostomy closure. The median distance from the anal verge to the anastomosis was 3 cm in both groups. Patients with carcinoma of the lower third of the rectum who require very low anterior resection with total mesorectal excision are better served with total rectal excision, construction of a colonic pouch and anastomosis of the pouch to the anus or anorectal junction, rather than joining the colon to an ischaemic rectal stump.
F. Seow-Choen Department of Colorectal Surgery Singapore General Hospital Singapore 03I6 1.
I.
2. 3.
Chant ADB. Compression and limb blood flow. BMJ 1970; ii: 235-6. Chant ADB. The effects of posture, exercise and bandage pressure on the clearance of 24Na from the subcutaneous tissues of the foot. Br J Surg 1972; 59: 552-5. Wood JE. The venous system. Sci Am 1968; 218(1): 86-96.
2.
Nicholls RJ, Lubowski DZ, Donaldson DR. Comparison of colonic reservoir and straight colo-anal reconstruction after rectal excision. Br J Surg 1988; 75: 318-20. Seow-Choen F. Controversies in colorectal surgery: colonic pouch after very low anterior resection for carcinoma of the distal third of the rectum. Ann Acad Med 1993 (in press).
Authors’ reply
Authors’ reply Sir In our paper we were trying to determine the role of compression on the large veins of the lower limb. Compression may or may not have an effect on arteries and capillaries but our work was not designed to examine that question. Theorizing on the value of ‘G’ suits was considered inappropriate and therefore not addressed. We have recently been investigating the effects of compression on the cutaneous microcirculation and have found a pronounced effect for similar levels of compression as achieved by commercial hosiery. We would agree with Mr Chant that the influence of compression on all components of the circulation should be investigated. S. Sarin J. H. Scurr P. D. Coleridge Smith Department of Surgery University College and Middlesex School of Medicine The Middlesex Hospiial London WIN 8AA UK
Sir We are grateful for the interest shown by Mr Seow-Choen in our paper, which looked at function of the distal rectum after low anterior resection for carcinoma. He has correctly pointed out that while there was only one leak in 27 patients when the anastomosis was 3 cm from the anal verge, there were five leaks in 56 when the anastomosis was 6cm from the anal verge. Contrary to his observations, however, there is in fact no statistically significant difference in these leak rates (P = 0.65, Fisher’s exact test), so we were reluctant to draw any conclusions from this difference. We are, however, very interested in the excellent functional results Mr Seow-Choen has obtained after total rectectomy with total mesorectal excision using the colonic pouch for reconstruction. Although his study has only 19 patients in two groups (colonic pouch-anal versus straight coloanal anastomoses), the early results for the colonic pouch-anal group appear promising. Our experience has also been that the few colonic pouch procedures we have performed have produced excellent functional results. Long-term studies with larger numbers will eventually determine the best form of reconstruction after total rectectomy with total mesorectal excision for lesions of the lower third of the rectum.
N. D. Karanjia R. J. Heald
Function of the distal rectum after low anterior resect ion for carcinoma Sir 1 am very uneasy with the conclusion reached by Karanjia, Schache and Heald (Br J Surg 1992; 79: 114-16). The authors selected two groups of patients with stapled anastomosis at median distances of 3 and 6 cm from the anal verge and found that postoperative anal function was superior in those with the higher anastomosis. They then concluded that this improvement in functional outcome justifies conservation of the distal rectum, and that as much of the distal rectum as possible should be preserved during very low anterior resection, while stressing total mesorectal clearance in the same breath. I agree that it is oncologically possible to reduce the distal margin of clearance to 1 cm during anterior resection and not see an increase in local recurrence rate. However, the preservation of as much rectum as possible after complete mobilization of the rectum with total mesorectal clearance and division of the lateral ligaments is not in accord with sound surgical principles. These manoeuvres tend to devascularize the rectal stump; the preservation of as much rectum as possible may therefore leave an ischaemic rectal stump with a higher risk of anastomotic breakdown. Indeed this is borne out in the authors’ paper. There was one leak in 27 patients (4 per cent) where the anastomosis was 3 cm from the anal verge, but were significantly more leaks (five in 56 patients; 9 per cent) where the anastomosis was at 6 cm. Improved postoperative anal function is better achieved with the use of the colonic pouch rather than leaving possible ischaemic rectal
1248
Colorectal Research Unii Basingstoke District Hospiial Basingstoke RG24 9NA UK
Primary papillary carcinoma of a thyroglossal duct cyst: report of a case and literature review Sir We were interested in the article by Weiss and Orlich (Br J Surg 1991; 78: 87-9 ), having ourselves recently excised a primary papillary carcinoma within a thyroglossal cyst. The patient was a 66-year-old man who presented with a lump in the neck that had been present for 10 years. He was asymptomatic but had sought advice because the lump had recently increased in size. Examination revealed a 3 x 3 cm firm midline swelling between the thyroid cartilage and hyoid that was not tender and did not transilluminate but moved cranially on protrusion of the tongue. The thyroid gland was clinically normal and there was no cervical lymphadenopathy. Ultrasonography of the neck confirmed a 3-cm cystic lesion separate from the thyroid gland. Technetium scanning demonstrated normal thyroid uptake and distribution with no evidence of pyramidal lobe activity. Thyroid function test results were normal.
Br. J. Surg., Vol. 79, No. 11, November 1992
Correspondence At elective operation the cyst was situated between the alae of the thyroid cartilage and fixed between the body of the hyoid and the thyroid cartilage, with the thyroglossal duct passing through the hyoid bone. The thyroid gland was macroscopically normal. A Sistrunk procedure was performed, and the patient made an uncomplicated recovery. Pathological examination showed a 5-mm papillary growth within the lumen of the cyst. Microscopic examination confirmed a thyroid papillary carcinoma and the presence of psammoma bodies. There was no evidence of invasion or lymphatic permeation. Follow-up thyroid function tests, computed tomography of the neck and isotope scanning revealed no further abnormalities. The patient was commenced on thyroxine to suppress thyroid-stimulating hormone (TSH), and no further surgery has been considered necessary. While agreeing with the authors that primary papillary carcinoma with no detectable metastases should be treated by a Sistrunk procedure without thyroidectomy, we would also advocate postoperative thyroxine administration. We believe that this is a sensible precaution, since papillary carcinoma of the thyroid gland is TSH dependent and it would be expected that a papillary carcinoma of a thyroglossal cyst would share this characteristic.
A. S. Bdesha G. T. Layer St Helier University Hospital Carshalton Surrey SM5 IAA UK
Py Io r us - p rese rv ing versus st a nd a rd pancreaticoduodenectomy: an analysis of 110 pancreatic and periampullary carcinomas Sir The British Journal of Surgery has repeatedly emphasized the importance of reliable statistical methods. However, this does not relieve the reader from critical judgement. The paper of Roder and colleagues (Br J Surg 1992; 79: 152-5) shows how strong conclusions can inappropriately be drawn from deficient statistical analysis. By using the word ‘uersus’ in the title the paper appears to be a controlled study, but it is not. Only the scrupulous reader may notice that the decision to perform either of two surgical procedures ‘was made according to the preference (my italics) of the senior surgeon performing the operation’, introducing an insuperable bias. Furthermore, many co-factors to the survival (i.e. tumour stage and grade) are disregarded simply by creating so many subgroups that the resulting small numbers are unable to establish any statistical significance. In this way a series of type I1 errors conceals what is actually missing: a multivariate analysis. I feel there is a great chance that the interpretation of the results of this otherwise impressive series of pancreatic resections could be entirely different from that reported. Therefore, I strongly recommend the authors to subject their survival data to a multiple regression analysis using the Cox proportional hazards model.
J. D. Blankensteijn Department of Surgery Massachusetts General Hospiial Boston Massachusetts 02114 USA
and methods section, our study was a retrospective analysis of data collected prospectively according to a standardized protocol. Of course we agree with Dr Blankensteijn that a randomized prospective trial comparing standard and pylorus-preserving pancreaticoduodenectomy would be the ultimate way to establish the superiority of one or other procedure. Because of the low number of patients undergoing resection in individual centres such a study has not so far been performed and probably never will be. We therefore feel that the results of our relatively large albeit retrospective series from a single centre merit publication because the findings are useful to establish new hypotheses. The distribution of tumour stage and grading in our patient population was shown in Table I and did not differ significantly between the two treatment groups. Our analysis, however, clearly demonstrated a superiority of standard pancreaticoduodenectomy, particularly in patients with stage 111 cancer of the head of the pancreas. According to Union Internacional Contra la Cancrum guidelines, tumour stage constitutes the strongest factor influencing survival. Since our analysis showed a significant difference in survival between the two procedures at various stages of the disease, a type I1 error could not occur. It can be useful (and is certainly trendy) to perform multivariate stepwise regression analysis to identify prognostic factors. However, the low number of patients in the present and all other studies precluded an intelligent application of this statistical tool. In fact, the limited number of cases in individual centres frequently does not allow separate analysis of even such different entities as pancreatic and periampullary carcinoma. In our opinion a meta-analysis of published data on the two procedures followed by a prospective randomized study would be the best way to clarify the issues. We are eagerly awaiting the results of such a study with multivariate analysis from Dr Blankensteijn. For the time being, standard pancreaticoduodenectomy with distal gastric resection remains the procedure of choice at our institution for resection of carcinoma of the head of the pancreas.
J. D. Roder H. J. Stein J. R. Siewert Department of Surgery Technische Universitat Miinchen Ismaninger StraJe 22 0-8000 Munich 80 Germany
Dual publication
Br. J. Surg.. Vol. 79, N o . 11. November 1992
again
Sir I noted again your difficulties with dual publication highlighted in the July issue (Br J Surg 1992; 79: 601) and your attempts to contact the principal authors. While spot checks and sanctions may help, I fear the problem is a symptom of a more serious maiaise afflicting surgery (and medicine) in general. The authors concerned in these episodes are victims of the crushing pressure placed on trainees to ‘publish or perish’. Trainees feel that publications, especially in a prestige journal, are the only overt yardstick used in deciding senior registrar appointments. Thus the pressure to maximize output during the period of full-time research, and hence dual publication, ‘salami slicing’ and ‘data manipulation’. While departments vary in strictness, some of the responsibility for this malaise must rest with the supervisors of these research projects. Ultimately the fault is generated by a system of advancement based almost quantitatively on publications to the exclusion of other factors. Until the profession as a whole addresses these attitudinal problems and resolves them sensibly, some form of ‘publication-stretching’ will always exist.
Authors‘ reply Sir We appreciate Dr Blankensteijn’s comments on our paper and thank you for the chance to address his concerns. As Voltaire said: ‘The best is the enemy of the good’, As clearly stated in the Patients
-
J. A. Haggie 10 Woodlark Close Winsford Cheshire CW7 3HL UK
1249
Mechanism of action of external compression on venous function Sir The article on compression and venous function by Sarin et al. (Br J Surg 1992; 79: 499-502) failed to address issues raised by myself’~2and Wood3, which showed the importance of maintaining external support at precisely the same level as the intravascular pressure in all postures. Such hydrostatic stockings or ‘G’ suits theoretically compensate for postural changes. The mechanism of external support therefore does not apply solely to veins, but also to arteries and capillaries.
A. D. B. Chant Royal Souih Hants Hospital Southampton SO9 4PE UK
stumps in very low anastomosis’,’. In a prospective randomized trial currently being conducted in this department with 19 patients to date, median frequencies of bowel movement per 24 h of 2 (range 0-5) and 5 (range 2-15) were obtained for pouch-anal and straight anastomoses respectively 1 month after ileostomy closure. The median distance from the anal verge to the anastomosis was 3 cm in both groups. Patients with carcinoma of the lower third of the rectum who require very low anterior resection with total mesorectal excision are better served with total rectal excision, construction of a colonic pouch and anastomosis of the pouch to the anus or anorectal junction, rather than joining the colon to an ischaemic rectal stump.
F. Seow-Choen Department of Colorectal Surgery Singapore General Hospital Singapore 03I6 1.
I.
2. 3.
Chant ADB. Compression and limb blood flow. BMJ 1970; ii: 235-6. Chant ADB. The effects of posture, exercise and bandage pressure on the clearance of 24Na from the subcutaneous tissues of the foot. Br J Surg 1972; 59: 552-5. Wood JE. The venous system. Sci Am 1968; 218(1): 86-96.
2.
Nicholls RJ, Lubowski DZ, Donaldson DR. Comparison of colonic reservoir and straight colo-anal reconstruction after rectal excision. Br J Surg 1988; 75: 318-20. Seow-Choen F. Controversies in colorectal surgery: colonic pouch after very low anterior resection for carcinoma of the distal third of the rectum. Ann Acad Med 1993 (in press).
Authors’ reply
Authors’ reply Sir In our paper we were trying to determine the role of compression on the large veins of the lower limb. Compression may or may not have an effect on arteries and capillaries but our work was not designed to examine that question. Theorizing on the value of ‘G’ suits was considered inappropriate and therefore not addressed. We have recently been investigating the effects of compression on the cutaneous microcirculation and have found a pronounced effect for similar levels of compression as achieved by commercial hosiery. We would agree with Mr Chant that the influence of compression on all components of the circulation should be investigated. S. Sarin J. H. Scurr P. D. Coleridge Smith Department of Surgery University College and Middlesex School of Medicine The Middlesex Hospiial London WIN 8AA UK
Sir We are grateful for the interest shown by Mr Seow-Choen in our paper, which looked at function of the distal rectum after low anterior resection for carcinoma. He has correctly pointed out that while there was only one leak in 27 patients when the anastomosis was 3 cm from the anal verge, there were five leaks in 56 when the anastomosis was 6cm from the anal verge. Contrary to his observations, however, there is in fact no statistically significant difference in these leak rates (P = 0.65, Fisher’s exact test), so we were reluctant to draw any conclusions from this difference. We are, however, very interested in the excellent functional results Mr Seow-Choen has obtained after total rectectomy with total mesorectal excision using the colonic pouch for reconstruction. Although his study has only 19 patients in two groups (colonic pouch-anal versus straight coloanal anastomoses), the early results for the colonic pouch-anal group appear promising. Our experience has also been that the few colonic pouch procedures we have performed have produced excellent functional results. Long-term studies with larger numbers will eventually determine the best form of reconstruction after total rectectomy with total mesorectal excision for lesions of the lower third of the rectum.
N. D. Karanjia R. J. Heald
Function of the distal rectum after low anterior resect ion for carcinoma Sir 1 am very uneasy with the conclusion reached by Karanjia, Schache and Heald (Br J Surg 1992; 79: 114-16). The authors selected two groups of patients with stapled anastomosis at median distances of 3 and 6 cm from the anal verge and found that postoperative anal function was superior in those with the higher anastomosis. They then concluded that this improvement in functional outcome justifies conservation of the distal rectum, and that as much of the distal rectum as possible should be preserved during very low anterior resection, while stressing total mesorectal clearance in the same breath. I agree that it is oncologically possible to reduce the distal margin of clearance to 1 cm during anterior resection and not see an increase in local recurrence rate. However, the preservation of as much rectum as possible after complete mobilization of the rectum with total mesorectal clearance and division of the lateral ligaments is not in accord with sound surgical principles. These manoeuvres tend to devascularize the rectal stump; the preservation of as much rectum as possible may therefore leave an ischaemic rectal stump with a higher risk of anastomotic breakdown. Indeed this is borne out in the authors’ paper. There was one leak in 27 patients (4 per cent) where the anastomosis was 3 cm from the anal verge, but were significantly more leaks (five in 56 patients; 9 per cent) where the anastomosis was at 6 cm. Improved postoperative anal function is better achieved with the use of the colonic pouch rather than leaving possible ischaemic rectal
1248
Colorectal Research Unii Basingstoke District Hospiial Basingstoke RG24 9NA UK
Primary papillary carcinoma of a thyroglossal duct cyst: report of a case and literature review Sir We were interested in the article by Weiss and Orlich (Br J Surg 1991; 78: 87-9 ), having ourselves recently excised a primary papillary carcinoma within a thyroglossal cyst. The patient was a 66-year-old man who presented with a lump in the neck that had been present for 10 years. He was asymptomatic but had sought advice because the lump had recently increased in size. Examination revealed a 3 x 3 cm firm midline swelling between the thyroid cartilage and hyoid that was not tender and did not transilluminate but moved cranially on protrusion of the tongue. The thyroid gland was clinically normal and there was no cervical lymphadenopathy. Ultrasonography of the neck confirmed a 3-cm cystic lesion separate from the thyroid gland. Technetium scanning demonstrated normal thyroid uptake and distribution with no evidence of pyramidal lobe activity. Thyroid function test results were normal.
Br. J. Surg., Vol. 79, No. 11, November 1992
Correspondence At elective operation the cyst was situated between the alae of the thyroid cartilage and fixed between the body of the hyoid and the thyroid cartilage, with the thyroglossal duct passing through the hyoid bone. The thyroid gland was macroscopically normal. A Sistrunk procedure was performed, and the patient made an uncomplicated recovery. Pathological examination showed a 5-mm papillary growth within the lumen of the cyst. Microscopic examination confirmed a thyroid papillary carcinoma and the presence of psammoma bodies. There was no evidence of invasion or lymphatic permeation. Follow-up thyroid function tests, computed tomography of the neck and isotope scanning revealed no further abnormalities. The patient was commenced on thyroxine to suppress thyroid-stimulating hormone (TSH), and no further surgery has been considered necessary. While agreeing with the authors that primary papillary carcinoma with no detectable metastases should be treated by a Sistrunk procedure without thyroidectomy, we would also advocate postoperative thyroxine administration. We believe that this is a sensible precaution, since papillary carcinoma of the thyroid gland is TSH dependent and it would be expected that a papillary carcinoma of a thyroglossal cyst would share this characteristic.
A. S. Bdesha G. T. Layer St Helier University Hospital Carshalton Surrey SM5 IAA UK
Py Io r us - p rese rv ing versus st a nd a rd pancreaticoduodenectomy: an analysis of 110 pancreatic and periampullary carcinomas Sir The British Journal of Surgery has repeatedly emphasized the importance of reliable statistical methods. However, this does not relieve the reader from critical judgement. The paper of Roder and colleagues (Br J Surg 1992; 79: 152-5) shows how strong conclusions can inappropriately be drawn from deficient statistical analysis. By using the word ‘uersus’ in the title the paper appears to be a controlled study, but it is not. Only the scrupulous reader may notice that the decision to perform either of two surgical procedures ‘was made according to the preference (my italics) of the senior surgeon performing the operation’, introducing an insuperable bias. Furthermore, many co-factors to the survival (i.e. tumour stage and grade) are disregarded simply by creating so many subgroups that the resulting small numbers are unable to establish any statistical significance. In this way a series of type I1 errors conceals what is actually missing: a multivariate analysis. I feel there is a great chance that the interpretation of the results of this otherwise impressive series of pancreatic resections could be entirely different from that reported. Therefore, I strongly recommend the authors to subject their survival data to a multiple regression analysis using the Cox proportional hazards model.
J. D. Blankensteijn Department of Surgery Massachusetts General Hospiial Boston Massachusetts 02114 USA
and methods section, our study was a retrospective analysis of data collected prospectively according to a standardized protocol. Of course we agree with Dr Blankensteijn that a randomized prospective trial comparing standard and pylorus-preserving pancreaticoduodenectomy would be the ultimate way to establish the superiority of one or other procedure. Because of the low number of patients undergoing resection in individual centres such a study has not so far been performed and probably never will be. We therefore feel that the results of our relatively large albeit retrospective series from a single centre merit publication because the findings are useful to establish new hypotheses. The distribution of tumour stage and grading in our patient population was shown in Table I and did not differ significantly between the two treatment groups. Our analysis, however, clearly demonstrated a superiority of standard pancreaticoduodenectomy, particularly in patients with stage 111 cancer of the head of the pancreas. According to Union Internacional Contra la Cancrum guidelines, tumour stage constitutes the strongest factor influencing survival. Since our analysis showed a significant difference in survival between the two procedures at various stages of the disease, a type I1 error could not occur. It can be useful (and is certainly trendy) to perform multivariate stepwise regression analysis to identify prognostic factors. However, the low number of patients in the present and all other studies precluded an intelligent application of this statistical tool. In fact, the limited number of cases in individual centres frequently does not allow separate analysis of even such different entities as pancreatic and periampullary carcinoma. In our opinion a meta-analysis of published data on the two procedures followed by a prospective randomized study would be the best way to clarify the issues. We are eagerly awaiting the results of such a study with multivariate analysis from Dr Blankensteijn. For the time being, standard pancreaticoduodenectomy with distal gastric resection remains the procedure of choice at our institution for resection of carcinoma of the head of the pancreas.
J. D. Roder H. J. Stein J. R. Siewert Department of Surgery Technische Universitat Miinchen Ismaninger StraJe 22 0-8000 Munich 80 Germany
Dual publication
Br. J. Surg.. Vol. 79, N o . 11. November 1992
again
Sir I noted again your difficulties with dual publication highlighted in the July issue (Br J Surg 1992; 79: 601) and your attempts to contact the principal authors. While spot checks and sanctions may help, I fear the problem is a symptom of a more serious maiaise afflicting surgery (and medicine) in general. The authors concerned in these episodes are victims of the crushing pressure placed on trainees to ‘publish or perish’. Trainees feel that publications, especially in a prestige journal, are the only overt yardstick used in deciding senior registrar appointments. Thus the pressure to maximize output during the period of full-time research, and hence dual publication, ‘salami slicing’ and ‘data manipulation’. While departments vary in strictness, some of the responsibility for this malaise must rest with the supervisors of these research projects. Ultimately the fault is generated by a system of advancement based almost quantitatively on publications to the exclusion of other factors. Until the profession as a whole addresses these attitudinal problems and resolves them sensibly, some form of ‘publication-stretching’ will always exist.
Authors‘ reply Sir We appreciate Dr Blankensteijn’s comments on our paper and thank you for the chance to address his concerns. As Voltaire said: ‘The best is the enemy of the good’, As clearly stated in the Patients
-
J. A. Haggie 10 Woodlark Close Winsford Cheshire CW7 3HL UK
1249
