217
PM, Johnson PC, Bell RL, et al. Regional ventilation and perfusion after lung transplantation in patients with emphysema. N Engl J Med 1970; 282: 245-49. 4. Vanderhoeft RJ, Rocmans P, Nemry C, et al. Left lung transplantation in a patient with emphysema. Arch Surg 1971; 103: 505-09. 5. Wildevuur R, Benfield JR. A review of 23 human lung transplantations by 20 surgeons. Ann Thorac Surg 1970; 9: 489-515. 6. Mal H, Andreassian B, Pamela F, et al. Unilateral lung transplantation in end-stage pulmonary emphysema. Am Rev Respir Dis 1989; 140: 3. Stephens
797-802.
7. Klepetko W, Laufer O, Laczkovics A, et al. Unilateral lung transplantation as an effective therapy in primary lung emphysema. Chirurg 1991; 62: 271. 8. Kaiser LR, Cooper JD, Trulock EP, et al. The evolution of single lung transplantation for emphysema. J Thorac Cardiovasc Surg 1991; 102: 333-41. 9. Lee PN, Fry JS, Forey BA. Trends in lung cancer, chronic obstructive lung disease, and emphysema death rates for England and Wales 1941-85 and their relation to trends in cigarette smoking. Thorax 1990; 45: 657-65. 10. Higgins N. Epidemiology of COPD: state of the art. Chest 1984; 85
(suppl): 3S-8S.
Pot-scourer
pleurodesis for pneumothorax
Spontaneous pneumothorax remains a common unpredictable event, especially among men. Development of tension always demands urgent pleural intubation, but in the less immediately threatening forms of pneumothorax management will depend on the extent of the pneumothorax and on the clinician’s assessment of a procedure in terms of its morbidity and risks, and the likelihood of preventing a recurrent episode. Possibilities include observation alone, simple aspiration of the air, pleural intubation with underwater seal drainage or a valve system, and either chemical pleurodesis or surgical pleurectomy. An earlier editorial concluded that, although simple aspiration might be a good way to manage small first pneumothoraces, persistent or recurrent pneumothoraces could be best treated with talc pleurodesis as a less invasive way of preventing recurrence than surgical pleurectomy. Anxieties about the long-term risks of talc have been discounted,2-4 but there is concern about the pain that can follow talc pleurodesis.5 In the search for other ways of preventing recurrence (20-50% risk of recurrence within 5 years), two reports offer further suggestions. Nkere et all used a domestic nylon scouring pad to abrade the parietal pleura, combined with ligation or stapling of pleural blebs and bullae. 60 patients with a persistent or recurrent pneumothorax were treated via a limited thoracotomy (10-12 cm incision); the pot-scourer was rubbed vigorously over the parietal pleura until capillary oozing occurred, and the visceral pleura was lightly scoured. Pleural drainage was continued for a median of 2 days, and patients were discharged about 4 days after the procedure. The researchers felt that this approach allowed earlier discharge than formal surgical pleurectomy; only 1 patient had a recurrence during follow-up of 18-52 months. Another approach was described by Wakabayashi et al, who used the carbon dioxide laser. 12 patients and
with persistent or recurrent pneumothorax were treated under general anaesthesia via a thoracoscope; blebs or bullae were treated with the laser to seal air leaks, with no accompanying pleurodesis. 3 patients required repeat procedures, and 1 had to have a surgical pleurectomy before the leakage of air ceased. Follow-up was not long enough to determine the overall success of the procedure. None of the existing studies allows us to judge the relative values of different techniques of pneumothorax therapy. This condition surely merits a controlled trial of some of the rival treatments. 1. Editorial. Spontaneous pneumothorax. Lancet 1989; ii: 843-44. 2. Research Committee of the British Thoracic Association and the Medical Research Council Pneumoconiosis Unit. Survey of the long-term effects of talc and kaolin pleurodesis. Br J Dis Chest 1979; 73: 285-88. 3. Lange P, Mortensen J, Groth S. Lung function 22-25 years after treatment of spontaneous pneumothorax with talc poudrage or simple drainage. Thorax 1988; 43: 599-61. 4. McGahren ED, Teague WG, Flanagan T, White B, Rodgers BM. The effects of talc pleurodesis on growing swine. J Ped Surg 1990; 25: 1147-51. 5. van Renterghem D, Bogaerts Y, Willemot JP. Spontaneous pneumothorax. Lancet 1989; ii: 1464. 6. Nkere UU, Griffin SC, Fountain SW. Pleural abrasion: a new method of pleurodesis. Thorax 1991; 46: 596-98. 7. Wakabayashi A, Brenner M, Wilson AF, Tadir Y, Berns M. Thoracoscopic treatment of spontaneous pneumothorax using carbon dioxide laser. Ann Thorac Surg 1990; 50: 786-90.
Anismus and biofeedback Acts that increase intra-abdominal pressure-eg, coughing, walking, getting up from a chair, and even
speaking- are always accompanied by compensatory increases in activity of the external sphincter and puborectalis muscles of the pelvic floor. This spinal reflex saves us from the embarrassment of inadvertent passage of flatus or faeces, but must be inhibited to facilitate the satisfactory expulsion of solid faeces from the rectum during defaecation. In 1984, Preston and Lennard-Jones from St Mark’s Hospital, London, reported that many patients with severe constipation are unable to facilitate defaecation by relaxing the pelvic floor; instead, both the external sphincter and the puborectalis contract when such patients strain to defaecate, as they would in response to a rise in intra-abdominal pressure caused by any other event. The researchers called this condition anismus. Had Preston and Lennard-Jones discovered the holy grail of constipation? To be certain, we need to ask three questions. Is anismus specific to constipation? Is anismus ever the only physiological abnormality in a constipated patient? And most important, can abolition of paradoxical contraction of the pelvic floor restore a normal pattern of defaecation? The finding of anismus is not confined to patients with constipation; the condition has been observed in 48% of patients with solitary rectal ulcer syndrome and in 33% of those with unexplained perineal pain who have no difficulty in defaecation.2 Anismus has also been documented in normal subjects, although
218
having one’s most private and solitary act observed on an X-ray screen while a needle is inserted into a highly sensitive part of the anatomy cannot be regarded as entirely conducive to normal defaecation. If anismus were the predominant abnormality in patients with severe constipation, we might expect digital examination to reveal a rectum packed with faeces awaiting expulsion. However, the rectum in constipated adults with anismus is usually empty, and these patients often have other abnormalities including colonic inertia, rectal insensitivity, and disturbances in internal sphincter function.3,4The impression gained from physiological studies is that anismus in severe constipation is just one component of a global disturbance in the central control of defaecation, so treatments aimed at correcting this single component would be of limited value. Is this true? Can treatment to diminish or abolish the paradoxical contraction of the external sphincter and puborectalis resolve constipation? Surgical division of the puborectalis and external sphincter had some success,5,6 but was accompanied by an unacceptable risk of faecal incontinence. Paralysis of the sphincter with botulinum toxin was likewise successful in a few patients,but the treatment had to be repeated several times and, as with surgery, there was a considerable risk of incontinence. Even sidelining the sphincter by diverting the flow of faeces through a distal colostomy has failed to relieve severe constipation in some patients with anismus. Theoretically, the most useful means of treating anismus is by biofeedback techniques: patients are trained to relax their sphincter when they strain to defaecate while retaining normal sphincter responses to events that threaten continence. Bleijenberg and Kuijpers8 achieved impressive results in their initial series of severely constipated young women from the Netherlands, but the lengthy hospital admission, and the extensive psychotherapy that these patients received, may have been more beneficial than the biofeedback itself. Many other centres have been disappointed in biofeedback for adult constipation, although the technique seems to work well in young children with impacted masses of faeces in the rectum.9 The biggest disadvantage to biofeedback was its requirement for hospital admission and expenditure of expert time and effort. Biofeedback for constipation was simply not cost effective-that is until Kawimbe and surgical colleagues1o in Edinburgh reported their results. The approach used by these researchers did not require patients to be admitted to hospital. It did not even require extensive psychological training; the patients did it all themselves. They were instructed to relax their anal sphincter by use of a simple plug electrode inserted into the anus and connected to an
electromyograph (EMG) display or to a loudspeaker, in which the frequency of the sound waves varied with the EMG level. The technique was tested on 15
patients-12 women and 3 men with "intractable constipation and excessive straining at stool due to difficulty in evacuating the rectum". This group had an average frequency of defaecation of 5-2 bowel actions per week, so they were not as constipated as patients in other series. Nevertheless, they all had evidence of anismus, recorded via the anal plug electrode. They were instructed to use the device to reduce the activity of the anal sphincter during straining every day for at least two weeks. 8 patients used it for 2 weeks, 6 for 4 weeks, and 1 for 6 weeks. The anismus index was greatly reduced after this training period and patients had more bowel movements, spent less time in straining, and had less perineal discomfort. This improvement was maintained over a follow-up period of 2 years. Another study" likewise showed a striking improvement in defaecation, this time in 16 constipated patients after a single training session in the laboratory. These results suggest that biofeedback correction of anismus can be a simple, useful, and cost-effective means of treating constipation. 1. Preston DM, Lennard-Jones JE. Anismus in chronic constipation. Dig Dis Sci 1985; 30: 413-18. 2. Jones PN, Lubowski DZ, Swash M, Henry MM. Is paradoxical contraction of puborectalis muscle of functional importance? Dis Colon Rectum 1987; 30: 667-70. 3. Miller R, Duthie GS, Bartolo DCC, Roe AM, Locke-Edmunds J, Mortensen NJMcC. Anismus in slow transit constipation. Br J Surg 1991; 78: 690-92. 4. Read NW, Timms JM, Barfield LJ, Donnelly TC, Bannister JJ. Impairment of defecation in young women with severe constipation. Gastroenterology 1986; 90: 53-60. 5. Wallace WC, Madden WM. Experience with partial resection of puborectalis muscle. Dis Colon Rectum 1969; 12: 196-200. 6. Barnes PRH, Hawley PR, Preston DM, Lennard-Jones JE. Experience of posterior division of the puborectalis muscle in the management of chronic constipation. Br J Surg 1985; 72: 475-78. 7. Hallan RI, Williams NS, Melling J, Waldron DJ, Womack NR, Morrison JFB. Treatment of anismus in chronic constipation with botulinum A toxin. Lancet 1988; ii: 714-17. 8. Bleijenberg G, Kuijpers HC. Treatment of spastic pelvic floor syndrome with biofeedback. Dis Colon Rectum 1987; 30: 108-11. 9. Loening-Baucke V. Modulation of abnormal defecation dynamics by biofeedback treatment in chronically constipated children with encopresis. J Pediatr 1990; 116: 214-22. 10. Kawimbe BM, Papachrysostomou M, Binnie NR, Clare N, Smith AN. Outlet obstruction constipation (anismus) managed by biofeedback. Gut 1991; 32: 1175-79. 11. Lestar B, Penninckx F, Kerremans R. Biofeedback defaecation training for anismus. Int J Colorect Dis 1991; 6: 202-07.
Neural tube closure retains its secrets Anyone studying the origin of neural tube defects might do well to start by considering early morphogenesis.l Both intrinsic factors in individual neuroepithelial cells and extrinsic factors are important in neural tube formation (primary neurulation). The notochord, for example, is believed to play a direct part in neurulation: it induces formation of the embryonic/neural axis, although the chemical signals have yet to be determined. The somites probably have a more complex role; they may influence the segmental arrangement of the neural axis.
PM, Johnson PC, Bell RL, et al. Regional ventilation and perfusion after lung transplantation in patients with emphysema. N Engl J Med 1970; 282: 245-49. 4. Vanderhoeft RJ, Rocmans P, Nemry C, et al. Left lung transplantation in a patient with emphysema. Arch Surg 1971; 103: 505-09. 5. Wildevuur R, Benfield JR. A review of 23 human lung transplantations by 20 surgeons. Ann Thorac Surg 1970; 9: 489-515. 6. Mal H, Andreassian B, Pamela F, et al. Unilateral lung transplantation in end-stage pulmonary emphysema. Am Rev Respir Dis 1989; 140: 3. Stephens
797-802.
7. Klepetko W, Laufer O, Laczkovics A, et al. Unilateral lung transplantation as an effective therapy in primary lung emphysema. Chirurg 1991; 62: 271. 8. Kaiser LR, Cooper JD, Trulock EP, et al. The evolution of single lung transplantation for emphysema. J Thorac Cardiovasc Surg 1991; 102: 333-41. 9. Lee PN, Fry JS, Forey BA. Trends in lung cancer, chronic obstructive lung disease, and emphysema death rates for England and Wales 1941-85 and their relation to trends in cigarette smoking. Thorax 1990; 45: 657-65. 10. Higgins N. Epidemiology of COPD: state of the art. Chest 1984; 85
(suppl): 3S-8S.
Pot-scourer
pleurodesis for pneumothorax
Spontaneous pneumothorax remains a common unpredictable event, especially among men. Development of tension always demands urgent pleural intubation, but in the less immediately threatening forms of pneumothorax management will depend on the extent of the pneumothorax and on the clinician’s assessment of a procedure in terms of its morbidity and risks, and the likelihood of preventing a recurrent episode. Possibilities include observation alone, simple aspiration of the air, pleural intubation with underwater seal drainage or a valve system, and either chemical pleurodesis or surgical pleurectomy. An earlier editorial concluded that, although simple aspiration might be a good way to manage small first pneumothoraces, persistent or recurrent pneumothoraces could be best treated with talc pleurodesis as a less invasive way of preventing recurrence than surgical pleurectomy. Anxieties about the long-term risks of talc have been discounted,2-4 but there is concern about the pain that can follow talc pleurodesis.5 In the search for other ways of preventing recurrence (20-50% risk of recurrence within 5 years), two reports offer further suggestions. Nkere et all used a domestic nylon scouring pad to abrade the parietal pleura, combined with ligation or stapling of pleural blebs and bullae. 60 patients with a persistent or recurrent pneumothorax were treated via a limited thoracotomy (10-12 cm incision); the pot-scourer was rubbed vigorously over the parietal pleura until capillary oozing occurred, and the visceral pleura was lightly scoured. Pleural drainage was continued for a median of 2 days, and patients were discharged about 4 days after the procedure. The researchers felt that this approach allowed earlier discharge than formal surgical pleurectomy; only 1 patient had a recurrence during follow-up of 18-52 months. Another approach was described by Wakabayashi et al, who used the carbon dioxide laser. 12 patients and
with persistent or recurrent pneumothorax were treated under general anaesthesia via a thoracoscope; blebs or bullae were treated with the laser to seal air leaks, with no accompanying pleurodesis. 3 patients required repeat procedures, and 1 had to have a surgical pleurectomy before the leakage of air ceased. Follow-up was not long enough to determine the overall success of the procedure. None of the existing studies allows us to judge the relative values of different techniques of pneumothorax therapy. This condition surely merits a controlled trial of some of the rival treatments. 1. Editorial. Spontaneous pneumothorax. Lancet 1989; ii: 843-44. 2. Research Committee of the British Thoracic Association and the Medical Research Council Pneumoconiosis Unit. Survey of the long-term effects of talc and kaolin pleurodesis. Br J Dis Chest 1979; 73: 285-88. 3. Lange P, Mortensen J, Groth S. Lung function 22-25 years after treatment of spontaneous pneumothorax with talc poudrage or simple drainage. Thorax 1988; 43: 599-61. 4. McGahren ED, Teague WG, Flanagan T, White B, Rodgers BM. The effects of talc pleurodesis on growing swine. J Ped Surg 1990; 25: 1147-51. 5. van Renterghem D, Bogaerts Y, Willemot JP. Spontaneous pneumothorax. Lancet 1989; ii: 1464. 6. Nkere UU, Griffin SC, Fountain SW. Pleural abrasion: a new method of pleurodesis. Thorax 1991; 46: 596-98. 7. Wakabayashi A, Brenner M, Wilson AF, Tadir Y, Berns M. Thoracoscopic treatment of spontaneous pneumothorax using carbon dioxide laser. Ann Thorac Surg 1990; 50: 786-90.
Anismus and biofeedback Acts that increase intra-abdominal pressure-eg, coughing, walking, getting up from a chair, and even
speaking- are always accompanied by compensatory increases in activity of the external sphincter and puborectalis muscles of the pelvic floor. This spinal reflex saves us from the embarrassment of inadvertent passage of flatus or faeces, but must be inhibited to facilitate the satisfactory expulsion of solid faeces from the rectum during defaecation. In 1984, Preston and Lennard-Jones from St Mark’s Hospital, London, reported that many patients with severe constipation are unable to facilitate defaecation by relaxing the pelvic floor; instead, both the external sphincter and the puborectalis contract when such patients strain to defaecate, as they would in response to a rise in intra-abdominal pressure caused by any other event. The researchers called this condition anismus. Had Preston and Lennard-Jones discovered the holy grail of constipation? To be certain, we need to ask three questions. Is anismus specific to constipation? Is anismus ever the only physiological abnormality in a constipated patient? And most important, can abolition of paradoxical contraction of the pelvic floor restore a normal pattern of defaecation? The finding of anismus is not confined to patients with constipation; the condition has been observed in 48% of patients with solitary rectal ulcer syndrome and in 33% of those with unexplained perineal pain who have no difficulty in defaecation.2 Anismus has also been documented in normal subjects, although
218
having one’s most private and solitary act observed on an X-ray screen while a needle is inserted into a highly sensitive part of the anatomy cannot be regarded as entirely conducive to normal defaecation. If anismus were the predominant abnormality in patients with severe constipation, we might expect digital examination to reveal a rectum packed with faeces awaiting expulsion. However, the rectum in constipated adults with anismus is usually empty, and these patients often have other abnormalities including colonic inertia, rectal insensitivity, and disturbances in internal sphincter function.3,4The impression gained from physiological studies is that anismus in severe constipation is just one component of a global disturbance in the central control of defaecation, so treatments aimed at correcting this single component would be of limited value. Is this true? Can treatment to diminish or abolish the paradoxical contraction of the external sphincter and puborectalis resolve constipation? Surgical division of the puborectalis and external sphincter had some success,5,6 but was accompanied by an unacceptable risk of faecal incontinence. Paralysis of the sphincter with botulinum toxin was likewise successful in a few patients,but the treatment had to be repeated several times and, as with surgery, there was a considerable risk of incontinence. Even sidelining the sphincter by diverting the flow of faeces through a distal colostomy has failed to relieve severe constipation in some patients with anismus. Theoretically, the most useful means of treating anismus is by biofeedback techniques: patients are trained to relax their sphincter when they strain to defaecate while retaining normal sphincter responses to events that threaten continence. Bleijenberg and Kuijpers8 achieved impressive results in their initial series of severely constipated young women from the Netherlands, but the lengthy hospital admission, and the extensive psychotherapy that these patients received, may have been more beneficial than the biofeedback itself. Many other centres have been disappointed in biofeedback for adult constipation, although the technique seems to work well in young children with impacted masses of faeces in the rectum.9 The biggest disadvantage to biofeedback was its requirement for hospital admission and expenditure of expert time and effort. Biofeedback for constipation was simply not cost effective-that is until Kawimbe and surgical colleagues1o in Edinburgh reported their results. The approach used by these researchers did not require patients to be admitted to hospital. It did not even require extensive psychological training; the patients did it all themselves. They were instructed to relax their anal sphincter by use of a simple plug electrode inserted into the anus and connected to an
electromyograph (EMG) display or to a loudspeaker, in which the frequency of the sound waves varied with the EMG level. The technique was tested on 15
patients-12 women and 3 men with "intractable constipation and excessive straining at stool due to difficulty in evacuating the rectum". This group had an average frequency of defaecation of 5-2 bowel actions per week, so they were not as constipated as patients in other series. Nevertheless, they all had evidence of anismus, recorded via the anal plug electrode. They were instructed to use the device to reduce the activity of the anal sphincter during straining every day for at least two weeks. 8 patients used it for 2 weeks, 6 for 4 weeks, and 1 for 6 weeks. The anismus index was greatly reduced after this training period and patients had more bowel movements, spent less time in straining, and had less perineal discomfort. This improvement was maintained over a follow-up period of 2 years. Another study" likewise showed a striking improvement in defaecation, this time in 16 constipated patients after a single training session in the laboratory. These results suggest that biofeedback correction of anismus can be a simple, useful, and cost-effective means of treating constipation. 1. Preston DM, Lennard-Jones JE. Anismus in chronic constipation. Dig Dis Sci 1985; 30: 413-18. 2. Jones PN, Lubowski DZ, Swash M, Henry MM. Is paradoxical contraction of puborectalis muscle of functional importance? Dis Colon Rectum 1987; 30: 667-70. 3. Miller R, Duthie GS, Bartolo DCC, Roe AM, Locke-Edmunds J, Mortensen NJMcC. Anismus in slow transit constipation. Br J Surg 1991; 78: 690-92. 4. Read NW, Timms JM, Barfield LJ, Donnelly TC, Bannister JJ. Impairment of defecation in young women with severe constipation. Gastroenterology 1986; 90: 53-60. 5. Wallace WC, Madden WM. Experience with partial resection of puborectalis muscle. Dis Colon Rectum 1969; 12: 196-200. 6. Barnes PRH, Hawley PR, Preston DM, Lennard-Jones JE. Experience of posterior division of the puborectalis muscle in the management of chronic constipation. Br J Surg 1985; 72: 475-78. 7. Hallan RI, Williams NS, Melling J, Waldron DJ, Womack NR, Morrison JFB. Treatment of anismus in chronic constipation with botulinum A toxin. Lancet 1988; ii: 714-17. 8. Bleijenberg G, Kuijpers HC. Treatment of spastic pelvic floor syndrome with biofeedback. Dis Colon Rectum 1987; 30: 108-11. 9. Loening-Baucke V. Modulation of abnormal defecation dynamics by biofeedback treatment in chronically constipated children with encopresis. J Pediatr 1990; 116: 214-22. 10. Kawimbe BM, Papachrysostomou M, Binnie NR, Clare N, Smith AN. Outlet obstruction constipation (anismus) managed by biofeedback. Gut 1991; 32: 1175-79. 11. Lestar B, Penninckx F, Kerremans R. Biofeedback defaecation training for anismus. Int J Colorect Dis 1991; 6: 202-07.
Neural tube closure retains its secrets Anyone studying the origin of neural tube defects might do well to start by considering early morphogenesis.l Both intrinsic factors in individual neuroepithelial cells and extrinsic factors are important in neural tube formation (primary neurulation). The notochord, for example, is believed to play a direct part in neurulation: it induces formation of the embryonic/neural axis, although the chemical signals have yet to be determined. The somites probably have a more complex role; they may influence the segmental arrangement of the neural axis.
