Shouldice Is Superior to Bassini Inguinal Herniorrhaphy

Matthias Kux, MD, Norbert Fuchsj~iger, MD, Michael Schemper, PhD, Vienna, Austria

The original Bassini and Shouldiee methods for inguinal he rn io r rhaphy were tested against each o the r and against thei r respect ive variants that avoid pe rma ne n t suturing o f the internal oblique muscle. Seven hundred fifty inguinal hernia re- pairs were prospect ively al located to 1 o f 4 groups: group A: Bassini with absorbable sutures (polyglycolie acid); g roup B: Bassini with nonab- sorbable sutures (polyester); g roup C: Shouldice with four rows o f po lypropylene sutures; and group D: Shouldice with two rows of polypropy- lene sutures.

Ou tcome was cor re la ted to prospect ively de- fined types and risk factors such as d i rec t her- nia, repa i r fo r r e c u r r e n t hernia , hernial sac di- ame te r g rea te r than 8 cm, age g rea te r than 70 years , overweight, and chronic bronchitis . Actual (not actuarial) r e c u r r e n c e rates were de- t e rmined th rough clinical examinat ion by hospi- tal staff surgeons (not th rough informat ion by le t te r or phone) for 9 3 . 6 % of surviving patients.

Local complicat ions exclusive o f r e c u r r e n c e , but including the redoubtab le and litigious se- quelae o f testicular a t rophy and chronic ilioin- guinal pain, were significantly r educed f rom 6 . 3 % (group B and C) to 2 . 3 % by omitting pe r ma ne n t muscle sutures (groups A and D; P <0 .05) . However , the use of slowly absorbable suture mater ia l resulted in a d ispropor t ionate ly high r e c u r r e n c e ra te of 1 2 . 8 % in the modified Bassini g roup A. The original Bassini method , ie, division o f the transversalis fascia and repa i r with nonabsorbable sutures, as was used in group B, had an actual 2 -year r e c u r r e n c e ra te of 8 . 7 % , still a highly significant d i f ference com pa r e d with 3 . 6 % and 2 . 3 % for Shouldice groups C and D, respectively (P = 0 .012) . F o r repai r o f r e c u r r e n t hernia , the superior i ty o f the Shouldiee technique was not statistically significant: r e - r ecu r r ence ra te 7 . 6 % versus 1 3 . 5 % for the original Bassini g roup B. Repai r o f r e c u r r e n t hernia was the only patient- re la ted risk fac tor o f equal significance as the me thod o f repair .

From the Department of Surgery (MK, NF), St. Joseph Hospital and the Department of Medical Computer Sciences, Section of Clinical Biometrics (MS), University of Vienna, Vienna, Austria.

Requests for reprints should be addressed to Matthias Kux, MD, Department of Surgery, St. Joseph Hospital, Auhofstrasse 189, 1130 Vienna, Austria.

Manuscript submitted November 16, 1992, and accepted in revised form April 6, 1993.

The Shouldice technique is super ior to and more than mere ly a re invent ion o f Bassini's original method. The omission o f muscle sutures is physiologically sound and recommended for the Shouldice operat ion.

A t its centenary, the Bassini method of inguinal hemiorrhaphy was found to have long been corrupted

in North America by omission of its most important step, ie, division and repair of the transversalis fascia plane, t,2 In retracing the historical steps, Wantz ~ has speculated that the Shouldice technique was but the inadvertent North American reinvention of the authentic Bassini repair. Although it is true that the transversalis fascia repair is considered essential and the Bassini method is still the most widely used repair in Europe, recurrence rates are generally not as good as those reported for the Shouldice method in North America. 3.4 One might suspect that there is also a specific European corruption of the original Bassini, 5 widespread throughout Europe, which consists of the use of slowly absorbable suture material. 3 The prac- tice of avoiding nonabsorbable material for the Bassini stitches corresponds to the tacit modification of the origi- nal Shouldice method in which the third and fourth rows of sutures, ie, the muscle sutures, are omitted. 4 Without formal testing, it is believed instinctively that suturing the internal oblique muscle with nonabsorbable sutures may be responsible for such embarrassing and litigious com- plications as chronic ilioinguinal pain and testicular atro- phy. Basically, the whole concept of these sutures is at variance with modem knowledge of wound repair. 6

The present study was undertaken to subject the afore- mentioned hypotheses and assumptions to formal and comprehensive testing. The trial was begun after Euro- pean surveys on the practice of hernia repair became known 3 and before the U.S. discussion arose around the centenary of Bassini's technique, t,2 It will be shown that the Shouldice method is indeed superior to the Bassini inguinal hemiorrhaphy and that the reservations on the pristine form of both methods are entirely justified. Instinctively, surgeons fear that the original methods of both Bassini and Shouldice carry a high risk of local com- plications. In context with the momentary sprawling of methods, laparoscopic and others, the study serves to il- lustrate how much time may elapse before longstanding and worldwide attitudes and theories in hemiology can be evaluated scientifically.

PATIENTS AND M E T H O D S Seven hundred fifty inguinal hemiorrhaphies were

prospectively allocated to 1 of 4 groups: group A: Bassini with absorbable sutures (polyglycolic acid); group B: Bassini with nonabsorbable sutures (polyester); group C:

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TABLE I Distribution of Prognostic Factors and

Recurrence by Groups (%) Factor Group A Group B Group C Group D Male (vs female) 78 88 86 85 Age >70 years 30 26 26 24 Bronchitis/obesity 17 20 17 15 Direct hernia 38 36 32 39 Hernial sac 16 14 14 13

diameter >8 cm Recurrent repair 12 20 18 19 Recurrence 12.8 8.7 3.6 2.3

TABLE II Absolute Figures for Local Complications in Combined

Groups A" and D" and Groups Bt and C t Complication Groups A+D Groups B+C Abscess 3 5 Sinus 0 6 Neuralgia 2 5 Scrotal swelling 3 7 Testicular atrophy 0 2 Total 8/350* 25/400

"No permanent suture material at internal oblique muscle. tWith permanent sutures in oblique musculature. *P <0.05, when the results of groups A and D are compared with groups B and C.

TABLE III Overall Recurrence Rates for Bassini

and Shouldice Techniques Technique n Recurrence % Bassini 317 33 10.4 Shouldice 366 11 3.0

P <0.001 Relative risk of recurrence (odds ratio): 3:74

Shouldice with four rows of polypropylene sutures; and group D: Shouldice with two rows of polypropylene sutures.

The study was begun in 1985 as a randomized, con- trolled trial. After 2 years and enrollment of 150 cases in group A, recruitment for this group was closed because actuarial recurrence rates were unacceptably high. Consequently, the study design was modified: recruitment was prospective and consecutive for group B only until 200 cases were obtained. Likewise, 200 patients under- going hemiorrhaphy were recruited successively for both groups C and D. In total, three board certified surgeons and six residents were involved in the trial. In both the randomized and prospective parts, there was no element of surgeon selection or patient preference. Thus, prospec- tively defined risk factors, ie, male sex, age greater than 70 years, chronic bronchitis, obesity, direct hernia, her- nial sac diameter greater than 8 cm, and repair for recur- rent hernia, were evenly distributed among the treatment groups (Table I).

The dissection phase was identical for all groups: re- section of cremaster muscle to allow access and division

of the transversalis fascia as illustrated in the respective reference descriptions) -5 Indirect hernial sacs were freed and excised; direct sacs were freed and inverted behind the transversalis fascia. In the Bassini repair, the triple layer consisting of the divided transversalis fascia, the transversalis muscle, and the internal oblique muscle was appositioned to the inguinal ligament with interrupted su- tures, slowly absorbable or nonabsorbable according to groups A and B. In the Shouldice repair, the first contin- uous suture approximated the undersurface of the trans- verse aponeurotic arch to the iliopubic tract. At the deep inguinal ring, the first suture was returned upon itself, at- taching in a second layer the edge of the medial segment to the inguinal ligament. In the original Shouldice method (group C), a second continuous suture approximated also the flesh of the internal oblique muscle to the inguinal lig- ament in two additional rows. In the modified Shouldice method as performed in group D, the two superficial rows of muscle sutures were omitted. Braided uncoated polyester (Mersilene, Ethicon, Hamburg, Germany) was chosen for group B because, of all modem synthetic su- ture materials, it elicits the strongest fibroplastic response and most closely resembles silk, which was used by Bassini. 2,5 For the Shouldice groups, monofilament polypropylene (Prolene, Ethicon, Hamburg, Germany) was used as advocated by most surgeons outside the Shouldice Clinic. 4,6 In all groups, the external oblique aponeurosis was closed with an single continuous polyg- lycolic acid suture. Recurrence was determined through clinical examination by hospital staff surgeons for 683 hernias corresponding to a 93.6% follow-up of surviving patients. Data were coded and stored electronically in an IBM 3090 mainframe computer at the University of Vienna. For statistical analysis, programs FREQ and LO- GISTIC of SAS 7 were used. Associations of qualitative or dichotomized variables are described by contingency tables and accompanied by corresponding P values for chi-square tests. The independent prognostic importance of various single factors was studied by means of logis- tic regression analysis 8 and described as relative risk. This is estimated as the ratio of the odds of recurrence for the unfavorable versus the favorable level of a risk factor. Unadjusted, simple analyses are paralleled by results of adjusted analyses.

R E S U L T S When the hemiorrhaphy is performed under local anes-

thesia and the patient is asked to strain, it is immediately obvious that tension is more evenly distributed by the tech- nique used in the patients in group D than in any of the other techniques, which interfere grossly with the subtle muscle play protecting the inguinal floor from intra-ab- dominal pressure rise. Accordingly, postoperative wound edema and pain were much less and recovery was more prompt in patients in group D. In the other groups, some pain usually persisted for several weeks, about the time that slowly absorbable suture material takes to dissolve. The redoubtable sequelae of chronic ilioinguinal pain, in- fectious and testicular complications, were significantly re- duced in combined groups A and D, which avoided per- manent suture material in internal oblique muscle (Table

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II). However, more important than statistics is the fact that there were four cases of litigation and/or reoperation for neuralgia and two cases of litigation for testicular atrophy in groups B and C but none in groups A and D.

The combined Shouldice groups C and D had an over- all recurrence rate of 3.0%, a highly significant superior- ity over 10.4% for the combined Bassini technique of groups A and B (Table HI). Since distortions from ab- sorbable suture material and actuarial recurrence rates have been published as preliminary progress reports, 9,1° only nonabsorbable suture material (groups B, C, and D) and actual recurrence rates at the 2-year + 6 months cutoff point are referred to in the remainder of this report. Of 27 pa- tients found to have a recurrence at clinical examination, almost half were not aware of their recurrence. Had these conclusions been based on information by letter or phone, the results would not have shown significant differences, which, in fact, did exist between the authentic Bassini group B and the two Shouldice groups taken together or separately (Table IV). Overall differences were due to dif- ferences in repair for primary hernias (Table V). For re- pair of recurrent hernia, the superiority of the Shouldice technique was not statistically significant: re-recurrence rate of 7.6% (5 of 66) versus 13.5% (5 of 37) for Bassini. Logistic regression analysis demonstrated that repair of re- current hernia was the only patient-related risk factor of equal significance as method of repair. (Hernial sac di- ameter of greater than 8 cm was a significant risk factor in group A only.) When compared with the 2-row Shouldice technique, the risk of recurrence was increased fourfold for patients of group B, ie, Bassini with nonab- sorbable sutures (Table VI).

C O M M E N T S Slowly absorbable suture material has been used at our

institution and, according to surveys, 3,9 most other institu- tions on the European continent for almost 20 years with- out any "apparent" negative effect on recurrence. Within the setting of a randomized, controlled trial, it took only 2 years to detect a forbiddingly high recurrence rate associ- ated with the use of this material, which invalidates the original technique of Bassini. Moreover, 100 years of in- ternational clinical experience with the "authentic" Bassini method proved to be fallacious when subjected to a rela- tively short scientific investigation rather than to the test of time. From the present study, it is evident that the Shouldice technique is superior to and more than merely "the inadvertent reinvention of the authentic Bassini method".1 However, the additional findings conceming the technical variants are of no less importance.

Both the original Bassini and Shouldice techniques rely on tight permanent suturing of the internal oblique mus- cle onto the inguinal ligament. This is at variance with modem concepts of the physiologic muscular shutter mechanism.a.4.t 1-14 Also, these sutures add more to the dan- gers of necrosis, infection, nerve entrapment, and testicu- lar ischemia than to lasting strength. Many surgeons and patients are not, or do not want to be aware of, recurrences; however, patients and surgeons are regularly, all too often in the courtroom, reminded of the complications of chronic ilioinguinal pain and testicular atrophy. Absorbable

TABLE IV Overall Recurrence Rates for

Bassini and Shouldice Techniques With Permanent Suture Material (groups B, C, D)

Technique n Recurrences % Bassini (Mersilene) 184 16 8.7 Shouldice (4 rows) 194 7 3.6 Shouldice (2 rows) 172 4 2.3

P = 0.012

TABLE V Recurrence Rates of Primary Repairs

for Groups B, C, and D Technique n Recurrences % Bassini (Mersilene) 147 11 7.5 Shouldice (4 rows) 160 4 2.5 Shouldice (2 rows) 140 2 1.4

P = 0.015

TABLE VI Analysis of Prognostic Factors by Logistic Regression

Factor

Simple Regression Multiple Regression Relative Relative

Risk P Risk P Male (vs female) 1.49 0.43 2.17 0.15 Age >70 years 1.15 0.77 1.40 0.50 Bronchitis/obesity 1.36 0.47 1.21 0.69 Direct hernia 2.36 0.031 1.99 0.10 Hernial sac 1.07 0.90 1.24 0.69

diameter >8 cm Recurrent repair 2.72 0.016 2.97 0.013 Group B vs C 2.54 0.045 3.26 0.021 Group B vs D 4.00 0.015 4.60 0.010

Bassini stitches or avoidance of muscle sutures, as in the two-row modification of the original Shouldice technique, significantly reduced these embarrassing and litigious complications. Although the figures from this trial cor- roborate the precautions instinctively adopted by many sur- geons, they also raise the question of why the "original" methods gave better results in the hands of their inventors. Specialization in hernia surgery has been proposed to im- prove results and to organize controlled studies. 15 So far, neither specialized centers nor university departments have engaged in the task the former having too little interest in science, the latter too little interest in hemia surgery. With their local patient recruitment, district hospitals are better suited for close clinical follow-up and avoidance of selection bias.

In this regard, it is remarkable that the statistically sig- nificant differences in this trial are attributable to infor- mation obtained by physical examination of patients. Bassini's follow-up was also remarkable, but so was his patient population: more than one third of his patients were under the age of 20 years, and an additional 15% were children from 13 months to 14 years of age/Although this does not lessen his achievement, it serves to remind mod-

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era-day pioneers that in hemiology, as in any other field of surgery, reporting treatment results without a control group may be misleading. The good results from the Shouldice technique at the Shouldice Hospital may be due to the original Shouldice technique itself. However, they may also be due to the extreme specialization of the sur- geons at that institution; they may be due to patient selec- tion or any of the other factors peculiar to this institution. In other words, under these circumstances the surgeons might achieve equally good results with another technique than the Shouldice technique.

With regard to patients, methods, and results, we have no doubt that our data reflect the actual status of hernia re- pair more accurately and raise some questions that may seem redundant in light of the extremely good results of the original institutions of Bassini and Shouldice or other specialized hernia surgeons. 3'5'12.14 Is incision and repair of a strong inguinal floor mandatory, or, in other words, is any single method adequate for all types of hernia? From our experience, we agree with Nyhus et al t2 and Peacock 16 that both the original Bassini and the Shouldice methods must now be considered overtreatment for type I and con- genital hernias. Conversely, no suture technique, however elaborate, can confer structural integrity to intrinsically de- ficient inguinal floor tissues. The preperitoneal and/or prosthetic repairs must have their place for these often re- current and more complex defects. 3'4'12,~4,17A8

In the last 5 years, 30 to 40 new techniques for hernia repair have been published; several "conventional" repairs and many laparoscopic techniques. This multitude of tech- niques is probably very confusing to the average surgeon. For primary hernia repair, the two-row Shouldice modifi- cation can be recommended and has been shown to be safe and practicable to that purpose without undue strain on specialization and technology.

R E F E R E N C E S 1.Wantz GE. The operation of Bassini as described by Attilio Catterina. Surg Gynecol Obstet. 1989;168:67-80. 2. Read RC. The centenary of Bassini's contribution to inguinal herniorrhaphy. Am J Surg. 1987; 153:324-326. 3. Houdard C, Stoppa R. Le traitement chirurgical des hernies de l'aine. Pads: Masson; 1984:77-80. 4. Wantz, GE. Atlas of Hernia Surgery. New York: Raven Press; 1991:60-80. 5. Bassini E. Ueber die Behandlung des Leistenbruches. Arch Kiln Chir. 1890;40:429--476. 6. Peacock EE. Wound Repair. Philadelphia: WB Saunders; 1984:129-139. 7. SAS/STAT. User's Guide. Version 6. Cary, NC: SAS Institute Inc., 1990. 8. Cox DR, Shell EJ. Analysis of Binary Data. 2nd ed. London: Chapman and Hall; 1980:20-28. 9. Fuchsjtiger N, Feichter A, Hirbawi A, Kux M. Bassini-Operation mit Polyglykolstiure oder Polyester. Chirurg. 1989;60:273-276. 10. Kux M, Fuchsj~iger N. Inguinal hernia repair. Br J Surg. 1989;76:766. Letter. 11. Condon RE. The anatomy of the inguinal region and its rela- tion to groin hernia. In: Nyhus LM, Condon RE, eds. Hernia. 3rd ed. Philadelphia: Lippincott; 1989:18--450. 12. Nyhus LM, Klein MS, Roger FB. Inguinal hernia. In: Wells SA, ed. Current Problems in Surgery. Vol 28. Littleton, Massachusens: Mosby-Year Book; 1991: 403--450. 13. Lytle WJ. The deep inguinal ring, development, function and repair. Br J Surg. 1970;57:531-536. 14. Gilbert AI. Sutureless repair of inguinal hernia. Am J Surg. 1992; 163:331-335. 15. Deysine M, Soroff HS. Must we specialize herniorrhaphy for better results? Am J Surg. 1990;160:239-240. 16. Peacock EE. Here we are: behind again! Am J Surg. 1989; 157:187. Editorial. 17. Read RC. Bilaterality and the prosthetic repair of large recur- rent inguinal hernias. Am J Surg. 1979;138:788-793. 18. Lichtenstein IL, Shulman AG, Amid PK. The tension-free hernioplasty. Am J Surg. 1989;157:188-193.

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