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PAPERS: H D E Atkinson, S G Nicol, S Purkayastha, and S Paterson-Brown Surgical management of inguinal hernia: retrospective cohort study in southeastern Scotland, 1985-2001 BMJ 2004; 329: 1315-1316 [Full text]

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What is a retrospective study?

Sabapathy P Balasubramanian   (4 December 2004)

Are mesh repairs causing infertility and other urogenital disorders?

Richard G Fiddian-Green   (5 December 2004)

What is a retrospective study? 4 December 2004
Sabapathy P Balasubramanian, Clinical Lecturer University of Sheffield S10 1NQ Send response to journal: Re: What is a retrospective study?	Sir I read the above article (1) with interest, as articles covering surgical topics are few and far between in general medical journals. This is due to various reasons and has been debated before (2-4). I am however intrigued by the design of this study, which looks more like a longitudinal survey of operative procedures over time rather than a ‘retrospective cohort’ as claimed in the title. A ‘retrospective cohort’ design would study a specific number of individuals identified in the past and followed up over a period of time to determine specific outcomes. What is described however is the incidence of different operative procedures over a time period. Assuming ‘recurrence’ was the outcome in this ‘cohort study’, we do not know if the recurrences occurred in the same set of patients who underwent the primary repair. The ratio of recurrent to primary repairs has certainly decreased over the same period of time as incorporation of the new techniques has increased. However, speculation over the cause of the decreased 'recurrent repairs' is invalidated by the study design and by the large number of potential factors, which have been inadequately explored. I am not sure if an association (let alone causation) between hernia recurrence and type of repair could be made from such a study. I would be grateful if the authors could describe the statistical methods used to ascertain the significance of the variation of the number of procedures over time. References: 1. Atkinson H, Nicol S, Purkayastha S, Paterson-Brown S. Surgical management of inguinal hernia: retrospective cohort study in southeastern Scotland, 1985-2001. BMJ 2004;329(7478):1315-1316. 2. Baum M. Publishing surgery. Lancet 2000;355(9213):1466. 3. Magos A, Cumbis A, Katsetos C. Bias against publication of surgical papers. Lancet 2000;355(9201):413. 4. Smith R. Publishing surgery. Lancet 2000;355(9206):849. Competing interests: None declared
Are mesh repairs causing infertility and other urogenital disorders? 5 December 2004
Richard G Fiddian-Green, FRCS, FACS c/o Sanders, Temple Gdns, Moor Park Send response to journal: Re: Are mesh repairs causing infertility and other urogenital disorders?	I did almost no inguinal herniorrhaphies after being appointed to the staff of an academic medical center in the US. I left the few that came my way to the chief resident to deal with as he/she saw fit largely because they had been trained to do the McVay, which I had not, and that was firmly held to be the standard of care in the region. My practice differed from that of many professors of surgery in the US who seem to regard "taking an intern though" their first hernia a right of passage and one of the more important responsibilities of being a professor of surgery. Some even appeared to elevate the first operation in their "watch one, do one, teach one" teaching format to a spiritual or mystical level. I hate doing inguinal hernias largely because I have found them very unsatisfactory operations, with the exception of a herniotomy in a infant, which were seriously limited by the uncertainties imposed by the anatomical constraints of the inguinal canal in a male. The most accomplished and apparently effective operations I have witnessed have been a darn done with braided silk by John Gasson at Groote Schuur, the Shouldice repair done by Nick Barwell at the Royal Devon in Truro, and latterly the laparoscopic repair done by Professor Bailey at the Royal Surrey in Guildford. My mentor, Professor Jannie Louw at Groote Schuur, condemned the use of braided silk ad non-absorbable meshes because of their propensity to become irreversibly infected and did a Bassini using monfilament nylon with unaudited results. What I have done in my paediatic surgical rotation is be party to operations for a few varicoceles and brought a fair number of undescended testes back into the scrotum. These were illuminating exercises principally because they demonstrated the vulnerability of the testis to vascular compromise and its potentially irreversible consequences, infertility and even testicular atrophy. I found it hard to do a repair that was restricted to fascia that held sutures well and was not under excessive tension, regarding the Tanner slide and other anatomically distorting relaxing procedures dubious exercises. The hardest part of doing an inguinal herniorrhaphy was knowing just how tight to make the internal ring especially in a relaxed patient there being a trade-off between risk of recurrence at the internal ring and risk of infertility or even testicular atrophy. The common practice of leaving just enough room to fit the tip of a little finger, for example, is clearly a function of the degree of muscle relaxation if any present at the time. One of the risks in doing a herniorrhaphy is causing infertility by obstructing the vas deferens. The incidence of obstruction, which may be reversible, is reported to be as high as 26.7% in subfertile patients with a history of childhood herniorrhaphy (1). Furthermore "immunoglobulin (Ig)G and IgA class antisperm antibodies, which contribute to infertility, have been found to be positive in 55% and 18% of those patients with a vasal obstruction caused by inguinal herniorrhaphy and in 60% and 20% of vasectomized patients respectively; whereas these antibodies were positive in 13% and 0% of those patients with an epididymal obstruction of unknown etiology and in 8% and 3% of those patients with congenital bilateral absence of the vas deferens"(2). In looking at the problem from a different perspective "10 infertile men found to have sperm-agglutinating antibodies in serum and a history of inguinal herniorrhaphy the site of the previous operation was explored. Five of the men had an occlusion of the vas deferens and in three others spermatoceles were noted in the epididymis. The occlusion of the vas deferens was in the area of the previous herniorrhaphy"(3). If obstruction of the hard-walled vas can occur so commonly what of arterial and especially venous obstruction? Is it not likely to be far more common even if not manifest as a varicocele? In two thirds of couples failing to conceive the male partner is partially or entirely responsible (4). In addition to an assessment of the number, motility, and morphology of spermatozoids, investigation of the subfertile male should include "a spermocytogram, tests of anti- spermatozoid immunity, and a bacteriological analysis. The biological study of the seminal plasma is also of considerable value. Electron microscopy of sperm is valuable in asthenospermic men. A genetic and hormonal investigation is, nowadays, almost mandatory in all cases. Testicular biopsy with cryopreservation of testicular tissue and demonstration of a possible varicocele can also, in selected cases, be of great help". What of an inguinal herniorrhaphy and especially a bilateral herniorrhaphy and the risk of vas obstruction? As in Scotland (5) the open and laparoscopic mesh-based techniques dominates the inguinal hernia repair marketplace in the US today (6). The Lichtenstein tension-free mesh onlay repair is the most frequently performed inguinal hernia operation, with a recurrence rate of less than 1%. These reports evoke a déjà vu, the common but myopic use of recurrence rates alone in evaluating the earlier results of surgery for duodenal ulceration. It was not until Goligher's landmark Leeds/York study (7) and its aftermath (8) that the deficiencies in this practice were fully appreciated. Hence the evolution of Visick grading rather than recurrence rates for assessing the results of surgery. I was disparagingly critical of Kingsnorth's review of this subject claiming that his, "choice of a simpler operation [Lichtenstein mesh repair]... a poor solution to the poor standard of [general] surgery" in the UK (8). A concern I raised was the risk of late and avoidable problems, secondary infection and alteration in pattern of spread of pelvic malignant diseases, that might be induced by the presence of a non- absorbable mesh. What I had not considered was the possibility of increased risks of infertility in males and even of painful ejaculation and ascending infections in their urogential tracts and conceivably even dyspareunia in women. I am not able to find any relevant data on the subject in Pubmed other than the references I have already cited. Is the reduction in recurrences achieved with the Lichtenstein mesh repair accompanied by an increase risk in infertility and other urogenitial problems? Might the risks be greatest in males in whom a plug of mesh has been inserted into the canal or in whom the mesh has been placed directly over the extraperitoneal intra-abdominal portion of the vas deferens in the course of a laparoscopic repair? If so might an adaptation of Visick grading be preferrable to recurrence rates in assessing outcomes for inguinal herniorrhaphies? One of the guiding principles in my surgical treatment of duodenal uleration that emerged from the Leeds/York trial and its aftermath was being prepared to take successive bites at the cherry to avoid subjecting my patients to incapacitating postvagotomy/gastrectomy syndromes. In adopting the proximal gastric vagotomy before the advent of H2 receptor antagonists, for example, I accepted the higher recurrence rate in the knowledge that I could always add an antrectomy in the minority who might develop a recurrence and need it. Should a similar approach be adopted in the management of inguinal hernias, the first operation being restricted to a herniotomy and a Lytle's repair of the internal ring (9,10?. This involves sewing transversalis fascia, the layer upon which the strength of a Shouldice repair would appear from my observations to primarily depend. The beauty of the herniotomy and Lytle's repair is that they are confined to the anatomical abnormalities and do not impose new ones by distorting normal anatomy. In conclusion the evidence-base supporting the use of the Lichtenstein mesh repair has serious deficiencies. In advocating this repair for the majority in the interests of cost-effectiveness the interests of the individual could be sacrificed. In the case of disadvantaged patients who drink and have pain caused by chronic pancreatitis this is a large cohort(11). With 80 000 inguinal herniorrhaphies being performed each year in the UK alone the cohort of patients with infertility and other urogenital disorders that have been caused by the operations could be very significant. 1. Matsuda T. Diagnosis and treatment of post-herniorrhaphy vas deferens obstruction. Int J Urol. 2000 May;7 Suppl:S35-8. 2. Yamamoto M, Hibi H, Miyake K. The incidence of antisperm antibodies in patients with seminal tract obstructions. Nagoya J Med Sci. 1996 Mar;59(1-2):25-9. 3. Friberg J, Fritjofsson A. Inguinal herniorrhaphy and sperm- agglutinating antibodies in infertile men. Arch Androl. 1979 Jun;2(4):317-22. 4. Demoulin A. Male infertility. Rev Med Liege. 2003 Jul-Aug;58(7-8):456-60. 5. H D E Atkinson, S G Nicol, S Purkayastha, and S Paterson-Brown Surgical management of inguinal hernia: retrospective cohort study in southeastern Scotland, 1985-2001 BMJ 2004; 329: 1315-1316 6. Nathan JD, Pappas TN. Inguinal hernia: an old condition with new solutions. Ann Surg. 2003 Dec;238(6 Suppl):S148-57. 7. Alexander-Williams, John, and Cox, Alan G. After vagotomy. Butterworth, June 1969. 8. Goligher JC, Pulvertaft CN, De Dombal FT, Conyers JH, Duthie HL, Feather DB, Latchmore AJ, Shoesmith JH, Smiddy FG, Willson-Pepper J Five to eight-year results of Leeds-York controlled trial of elective surgery for duodenal ulcer. Br Med J. 1968 Jun 29;2(608):781-7. 9. Poor solutions for poor surgery. Richard G Fiddian-Green bmj.com, 10 Jan 2004 eLetter re: Andrew Kingsnorth Treating inguinal hernias BMJ 2004; 328: 59-60 9. LYTLE WJ. Anatomy and function in hernia repair. Proc R Soc Med. 1961 Nov;54:967-70. 10. Lytle WJ. The deep inguinal ring, development, function and repair. Br J Surg. 1970 Jul;57(7):531-6. 11. Should an excision biopsy have been performed four years earlier? Richard G Fiddian-Green (26 November 2004) eLetter re: Victor Meneghetti, Charles Lee, Thomas L. Perry, and Gordon Andrews An unusual structure near the porta hepatis: What's your diagnosis? CMAJ 2004; 171: 1048-1049 Competing interests: Objections to editorial selection and bias