THE SURGICAL MANAGEMENT OF IBD Crohn ' s disease : The benefits of minimal surgery

JJ TJANDRA, VW FAZIO. Crohn's disease: The benefits of minimal surgery. CanJ Gastroenterol l 993;7(2):254-257. The extent of surgery for small bowel Crohn's disease has been controversial. Evidence supporting extensive surgery and minimal surgery ( including strictureplasty) is reviewed. Minimal surgery does not appear to be associated with increased morbidity or recurrence rates. The weight of evidence supports the practice of minimal surgery to minimize the risk of iatrogenically-induced short bowel syndrome.

lowing resection for C rohn's disease 1s the difference in the various dcfinitiom of 'recurrence'.This can range from a relapse of clinical symptoms with or without endoscopic or radiologic evidence of recurrence to the need for reoperation with or without histologic confirmation.Recurrence races are highesl when the symptomatic criteria alone arc used and lowest when the reoperation rate is used.Endoscopic evidence of Crohn's disease may be present without any sympwms.In a study ( 4), evidence of anastomotic 'recurrence' was recognized endoscopically in as many as 72% of patients within one year of ileocolic resection and anasto mosis.Rigid scenosis was uncommon in the early postoperative period but was present in close to half the patients examined more than three years later ( 4) .Duratton of follow-up also varies between reports.Actuarial analysis ( S) may be a more accu rate method of reporting when length of fo llow-up varies.

EXTENT OF RESECTION
In earlier times, radical resection was considered necessary (6,7).The diseased segment with a wide margin of normal bowel on either side and all of the enlarged lymph nodes were removed (6,7).A margin of 10 cm was considered necessary in some centres TABLE 1 (8).The literature itself has been confusing with proponent~ and opponents of rad ical resection.

Proponents of radical resection in Crohn's disease
All these sludies were retrospective (Table l) and, in some cases, the rcliabilny of analysis of the resection margins was questionable (9).Some studies (8,10) included patients who had residual overt disease in the nonradical grour.This would have exaggerated the 'recurrence' rate in the non-radical resection group.In the scu<ly by Bergman and Krause (8), recurrences not at the anastomosis were also included in the study; most importantly, the radical operations were performed at a different institution from the nonradical or control orerations.Differences in patient population and surgical teams further confuse the outcome.Another study ( 11) with a short follow-up (Table l) hased the diagnosis of 'recurrence' on radiologic changes alone and clinical symptoms were not ccms1dered.It is possible that asymptomatic, radiologic changes of Crohn's disease are more common 111 the nonradical resection group.Histologic criteria for a positive margin in these studies were not clear.
Several studies, on the contrary, have failed co find any association between the length of resection margin and recurrence ( l 2-14).Furthermore, to preserve smal l bowel length, the length of the resection margin tends to he inversely related to the length of active Crohn's disease resected, in rhat patients with long disease segments rend co have short resection margins.As one study showed ( 14), although a higher recurrence rate was noted with shorter resection margins, iL was not independent of the length of active disease resccted.Relationship to recurrence was not present when the length of the margin was analyzed independent of th e length of active disease in the specimen.Thus, reports claiming a poorer prognosis for shnrr resection margins may reflect a longer length of active disease in these patients.
A more conservative resection may abo he applied to patients with diffuse involvement of the small bowel.However, patients with diffu~e disease have •cumulative recurrence rate was reported been shown to have a higher incidence of recurrence than those with singlesite disease ( 15).This may further account for the higher recurrence rates with a short resection margin in some studies.

MICROSCOPIC DISEASE AT RESECTION MARGINS
The influence of microscopic disease at resection margins on the recurrence rates has been contentious.Many of the studies on resection margins have been criticized for inclusion of patients with Crohn's colitis ( 16-20) where the preferred surgical approach may not be segmental resection and the distinction between Crohn's disease and ulcerative colitis can be difficult.l n some cases, reoperativc cases were included (16,17).Histologic criteria for positive margins were variable (16, 18-20) and sometimes not given (21 ).
Some centres have advocated intraoperative frozen section examinations to ensure disease-free resection margins (16,21-23).However, microscopic changes are easily missed in frozen sections (24).In a study (24), 60 of 61 bowel margins examined hy frozen sections were reported as negative but 20 of 61 margins were actually involved by Crohn's disease when examined by permanent histologic sections.Wolff ct al ( 16) reported the importance of microscopic disease at the resection margin on the recurrence rate.Microscopic evidence of disease was defined as mucosa!inflammation or ulceration, specifically excluding nonspecific submucosal or mtramuscular mflammation.The cumulative recurrence rate for this group (n=39) was 90% at eight years, compared with 47% for other patients (n=658) undergoing resection for Crohn's disease.

Wide ma~
Narrow ma!9!_rl 32°/o 85% 29% 31 % 28%' 84% 83% 52°/o' However, patients with microscopic disease (n=39) were retrospectively identtfied from the original pathology report and the histological sections of all operated cases ( n = 710) were not reviewed with regard to the presence of disease at the resection margins.Furthermore, half of the patients with positive margins had skip areas of active macroscopic disease in the remaining bowel, which is known to be associated with a high recurrence rate (15,25).Thus the two groups of patients were not comparable.
Withm the past decade, many studies have shown that microscopic abnormalities at resection margins have little influence on anastomotic recurrence {13,17,18,20,21,26).However, in some of these studies (18,26), minor histologic changes were included as evidence of a positive margin.
To clarify some of these issues, a study of 100 patients having their first resection for small bowel or small and large bowel Crohn's disease was undertaken at the Cleveland Clinic (27).Diagnosis of recurrence was defined as the presence of symptoms with a demonstrable lesion at or near the anastomosis.Resection margins were categorized hy a single gastrointestinal pathologist as being histologically normal, showing changes of a nonspecific nature, showing changes suggestive of Crohn's disease and showing changes diagnostic of Crohn's disease.The histologic features evaluated for each resection margin arc shown in Table 2.
Recurrence at the anastomosis occurred in 50% of the patients at a mean follow-up of I l. 5 years.The cumulative recurrence races for rhe four margin categories were not stat1sucally different.Recurrence was also not associated with any specific clinical or  (27) hastologic feature.Furthermore, the cumulative recurrence rate of those patients in t he study who fu lfi lle<l the criteria of Wolff er a l ( 16) of a positive margin was not significantly different from the recurrence rates of any of the fo ur categories (2 7).
Whether or not frozen-section examination of resection margins in Crohn's disease affects the rate of anastomotic recurrence is not completely clear because a controll ed prospective trial has not yet been J one.A ll studies have been retrosrective.However, the body of evidence to date surpnrts a conservative attitude in intestinal resection, remov ing only overtly involved intestine.The ~afcty and efficacy of such an approach is further endorsed hy the fo llowing discussion on strictureplast y.

STRICTUREPLASTY
As an alte rnative L O extensive repeat resections, Lee from Oxford (28) pioneered the technique of stricrureplasty to relieve obstruction from shore fibrutic strictures of the small bowel.In subsequent studies (Tahle 3 ), it has been shown to be safe, effective and has the added advantage of bowel preservation.The principle and nomenclature of strictu replasty as similar to pyloroplasty.The surgical techniques have been described an detail elsewhere (34,35).A total of 452 stricrureplasttes have been rerformed in 116 patients at the Cleveland C lmic (33 ).The median number of str1crurepl<1st1es per patient was three (range.one to 15).Short strictures up to 10 cm are reconstructed transversely by Heinecke-Mikulicz and longer strictures up to 30 cm by Finney strictureplasty as in a side-to-side anastomosis.Synchronow, resections were undertaken in 71 (61%) patients.ln general, resections were performed for acute inflammatory phlegmon, overt perforation, fonalae, strictures longer than 30 cm and for mu luple st rictures within ::i short segment.

256
There was no operative morrnl1ty.The median duration between operation and discharge was nine days (range, six to 27 dr1ys).Major complications were uncommon despllc the inclusion of actively inflamed bowel in the suture line.Enterocutaneous fistulae with or without associated intraabdominal abscess developed in five ( 4%) patients.In two (2%) add itional patients, intra-abdominal abscess occurred without demonstrable fistula on contrast examination of the intestines.Reoperntaon for these septic complications was needed in two patients.The remainder were successfully managed with parenteral nutrinon, antibiotics, somatostmin fo r fistula and computer tomographic-guided drainage for intraabdominal abscess.
The median fo llow-up was three years (range six months to seven yea rs).Relief of obstructi ve symptoms, as assessed subjectively by the patient, was achieved in 115 (99°4>) patients.In the absence of frank sepsb, strictureplasty can also be performed 111 patients wtth active (16) and diffuse (3 7) small howel Crnhn's disease.Multiple (four or more) stnctureplastaes have been performed 111 patients with diffuse Crohn's disease of the small bowel (37).In this group of patients with a median number of seven strictureplast ics, the complacauon rate and outcome is no worse than fo r those who had undergone isolated ~tnctureplasties (28)(29)(30)(31)(32)(33)37).In another study (38), actuarial analys is has shown no difference 111 site-specific recurrence (hased on the need for reoperataon at that sate) between patients undergoing conventional resection and those undergomg strictureplast y.CONCLUSIONS lt appears from these studies that d iseased resection margins are of lmle significance with regard to recurrence rate.Conservative resection, removing only overt diseased segment, is theretore recommended.In selected cases of Crohn's disease with stricture, stric-Lureplasty can accomplish symptomatic re lief safely, min1m1ze the risk of short bowel syndrome and is a useful adj unct to resectinn.

TABLE 3 Major studies on strlctureplasty for Crohn's disease
Sternid use was 67% before and 23% ar six months after surgery.Symptomatic recurrence developed in 28 (24%) patients.Evidence o( d isease was