How Conservatively Can Postoperative Small Bowel Obstruction Be Treated?

How Conservatively Can Postoperative Small Bowel Obstruction Be Treated? Dan Seror, MD, Elad Feigin, MD, Amir Szold, MD, Tanir M. Allweis, MD, Moshe Carmon, MD, Shemuel Nissan, MD, Herbert R. Freund, MD, Jerusalem, Israel Although postoperative adhesion ileus is the most common cause of small bowel obstruction in adults, its management remains controversial. We retrospectively studied 297 admissions of 227 patients over a period of 14 years to evaluate our conservative approach in managing adhesion ileus. We found that nonoperative therapy of up to 5 days' duration can be used safely for the majority of patients who present with postoperative intestinal obstruetion, including those with complete obstruction. In those patients who responded to conservative treatment, the obstruetion resolved within a mean of 22 hours and a maximum of 5 days. A trial of more than 5 days' duration proved ineffective. The conservative approach resulted in a 73% resolution of obstruction with no significant increase in mortality or in the rate of strangulated bowel. From the Department of Surgery, Hadassah University Hospital Mount Scopus, and the Hebrew University-Hadassah Medical School, Jerusalem, Israel. Requests for reprints should be addressed to Herbert R. Freund, MD, Department of Surgery, Hadassah University Hospital Mount Scopus, PO Box 24035, Jerusalem, Israel 91240. Presented at the 33rd Annual Meeting of the Society for Surgery of the Alimentary Tract, San Francisco, California, May 11-13, 1992. A dhesive intestinal obstruction, which was a rare postoperative complication in the early advent of modern surgery [1], is now the most common form of intestinal obstruction [2-4]. Nevertheless, considerable controversy still exists concerning the ideal therapy for adhesive intestinal obstruction and the indications for and the timing of surgery. The main problem is how to avoid strangulation or other forms of bowel damage and still minimize the use of unnecessary operations. The dictum that acute intestinal obstruction should be treated by early operation [5] is countered by the acceptance of conservative treatment in selected cases. The present study retrospectively reviewed a large series of patients with postoperative intestinal obstruction, in whom conservative therapy was attempted as long as there was no sign of compromised bowel, and attempted to set guidelines for the indications and timing of surgery. PATIENTS AND METHODS We retrospectively analyzed the records of 227 patients with the diagnosis of postoperative small bowel obstruction who were admitted to the Department of Surgery at Hadassah University Hospital Mount Scopus in Jerusalem from 1976 through i990. Patients with multiple admissions for the same diagnosis were studied and entered as individual cases for a total of 297 admissions. The patients ranged in age from 6 months to 100 years (median: 54 years). Cases of early postoperative obstruction were excluded. The diagnosis was based on the patient's history, clinical evaluation, and radiographic findings, and whether the patient underwent operation and the findings during operation. The clinical course for each patient was outlined, depending upon whether the patient underwent operation or was treated conservatively, with special attention to the outcome and complications. Pertinent data, such as the presence of inflammatory bowel disease (IBD) or malignancy, the type of previous operation or previous irradiation, and the length of time of nasogastric intubation, intravenous administration of fluids, and hospital stay, were recorded. The operative findings and procedures were reviewed and analyzed as well. Statistical analysis was performed for the entire study group and separately for groups of special interest to assess the homogeneity of the results. Separate analyses were performed for the adult and pediatric populations, for patients presenting with partial or complete obstruction, and for patients who were previously hospitalized or surgically treated for adhesion ileus. SPSS-X software was used with a DEC Microvax 3900 VMSV-5.3 (Digital Corp.) for data analy, sis. analysis and Fisher's exact test were used to evaluate qualitative data, and Student's t-test was used to THE AMERICAN JOURNAL OF SURGERY VOLUME 165 JANUARY 1993 121

SEROR ET AL TABLE I Previous Operations in 297 Admissions for Postoperative Adhesion Ileus Last All Previous Operation Operations No. of No. of Site Admissions % Admissions % Appendix 30 10 53 18 Gallbladaer 37 12 47 16 Stomach 44 15 81 27 Genitourinary 40 13 64 21 Bowel not in pelvis 52 17 66 22 Bowel in the pelvis 24 8 28 9 Spleen 11 4 13 4 Hernia repair 35 11 55 18 Other 26 9 analyze quantitative comparisons. Discriminant analysis was used in attempted classification. RESULTS Two hundred twenty-seven patients required 297 admissions for intestinal obstruction after abdominal surgery. All the reported results refer to the 297 admissions. One hundred one patients (44%) had undergone 2 previous abdominal operations, and 30 (13%) had undergone 3 or more previous operations. Sixty-three (28%) were previously hospitalized for adhesion ileus, of whom 32 (14%) underwent operation. The type of the original abdominal operation did not correlate significantly with the clinical or operative course (Table I). Thirty-two patients (14%) had abdominal malignancy, 9 (4%) had IBD, and 6 (3%) had previous radiotherapy to the abdominal region. One hundred seventeen (40%) had constipation, and 219 (74%) experienced at least 1 episode of vomiting. One hundred forty patients described their pain as colicky and 28 as continuous. The pain was localized in 79 patients and diffuse in 109. The duration of pre-admission symptoms ranged from 2 hours to 30 days (median: 1 day; mean: 2.2 days). A total of 80 patients (27%) required surgery to relieve their obstruction. The mortality rate in the whole series was 2% (5 of 297). The mean body temperatures on admission in patients who underwent surgery and those who did not were 37.20C and 37.0~ respectively (p <0.05). The white blood cell (WBC) count averaged 12,000/mm 3 in the surgically treated group and 10,200/ mm3 in the conservative therapy group (p <0.01). Those patients with strangulated bowel had a mean WBC count of 11,300/mm 3 on admission and 11,800/mm 3 before surgery (p = NS). There were no differences in pulse rate between conservatively treated patients and surgically treated patients. Various admission and hospital parametric results are listed in Tables II and IlL The results of the abdominal roentgenogram that was obtained on admission showed complete obstruction in 166 patients (57%), partial obstruction in 118 (41%), and a normal film in 5 (2%). Of the 80 patients who had surgery, 65 (81%) had adhesions, 7 (9%) had an internal hernia, 6 (7%) had a tumor or malignant spread, and 2 (3%) were found to have intussusception. Strangulated bowel was found in 33 (41%) of the surgically treated patients. Bowel resection was necessary in 19 (24%) patients, and, in an additional 14 patients (18%), some type of enterostomy was required. The period of conservative treatment prior to surgical treatment ranged from 12 hours to 25 days (median: 2 days). Nineteen patients (24%) had conservative therapy for 5 days or longer, and 10 patients (12%) had conservative treatment for 10 days or more. Nasogastric drainage was required in the conservatively treated patients foran average of 2.8 days and in the surgically treated patients for an average of 9.0 days (p <0.001). The surgically treated patients required the administration of intravenous fluids for a mean of 10.3 days, whereas the conservatively treated patients required intravenous fluids for 3.7 days (p <0.001). The mean hospital stay was 7.6 days in the conservatively treated group and 19.7 days in the surgically treated group (p <0.001). These variables are summarized in Tables II and III and are calculated separately for the total and adult groups. We found no differences in the rate of patieiats undergo, ing surgery, the rate of bowel strangulation, or the mortality rate between patients with partial or complete obstruction (Table IV). Expectant treatment for a period longer than 5 days did not result in a significant increase in mortality or morbidity as shown by the presence of strangulated bowel during surgery (Table V). This result remained valid even when the patients who presented with complete obstruction only were considered (Table IV). Those patients who did not require surgery responded to conservative treatment and were relieved of their symptoms within a mean of 22 hours (median: 24 hours) and a maximum of 5 days. No patient responded to expectant therapy of longer than 5 days (Figure 1). Discriminant analysis for maximal separation between patients with or without strangulated bowel using all preoperative clinical and laboratory data was successful in only 65% of patients. COMMEI~TS Although postoperative intraperitoneal adhesions are well recognized as the most common cause of small bowel obstruction in adults [2-4,6-8], considerable controversy still exists regarding their pathogenesis [9-11], the overall outcome and mortality (Table VI), and the recommended therapeutic strategy. It is also difficult to find a strong correlation between one or more of the classic signs of strangulated bowel, e.g., fever, leukocytosis, tachycardia, localized tenderness, or the presence of irreversible damage to the intestines [12-15]. Previous studies have attempted to devise a formula that would predict the presence of compromised bowel based on preoperative data, but they have failed to reach a sufficiently accurate classification or prediction [15-19]. The data from this current series also resulted in a less-than-optimal classification rate of only 65%. A traditional distinction is currently employed between patients with complete obstruction and those with partial intestinal obstruction. Whereas complete obstruction is generally defined by the 122 THE AMERICAN JOURNAL OF SURGERY VOLUME 165 JANUARY 1993

POSTOPERATIVE SMALL BOWEL OBSTRUCTION TABLE II Hospital Variables in 297 Admissions for Postoperative Adhesion Ileus: Operated Versus Conservatively Treated Patients Total Series Adults Only (Age _> 15) OP NOP p Value OP NOP p Value No. ol patients 80 217 73 204 Age (y) 53.3 50.2 NS 57,4 53.4 NS Duration of complaints before admission (d) 2.9 1.9 NS 3,0 1.9 NS Temperature on admission (~ 37.2 37.0 0.05 37,2 37.0 NS Pulse on admission (min) 89 87 NS 88 85 NS White blood cell count on admission (/mm 3) 12,000 10,200 0.01 11,700 10,000 0.05 Days with nasogastric tube 9.0 2.8 0.001 8.9 2.8 0.001 Days with intravenous line 10.3 3.7 0.001 10,2 3.7 0.001 Days in hospital 19.7 7.6 0.001 19,8 7.8 0.001 op = operated; NOP = not operated upon; NS = not significant. TABLE Ill Hospital Variables in 297 Admissions for Postoperative Adhesion Ileus: Strangulated Versus Viable Bowel (Operative Findings) Total Series Adults Only (Age ~ 15) Strangulated Viable p Value Strangulated Viable p Value No. of patients 33 Age (y) 57.2 Duration of complaints before admission (d) 3.0 Temperature on admission (~ 37.3 Pulse on admission (rain) 92 White blood cell count on admission (/mm 3) 11,500 Days with nasogastric tube 7.7 Days with intravenous line 9.1 Days in hospital 19.0 NS = not significant. 44 33 37 50.2 NS 57.2 61.0 NS 1.8 NS 3.0 1.8 NS 37.1 NS 37,3 37.0 NS 86 NS 92 85 0.05 11,300 NS 11,300 10,100 NS 6.0 NS 7.7 5.7 NS 7.0 NS 9.1 6.7 NS 14.0 NS 18.9 13.8 NS complete lack of passage of stool or flatus and no evidence of gas observed on the plain abdominal films distal to the site of obstruction, this definition is impractical, since air can be found in the colon during the early stage of complete obstruction, or it may be introduced into the rectum by digital examination or other manipulations [16]. Some authors recommend mandatory operation for any patient who presents with complete obstruction and advise the use of conservative management for patients with partial obstruction only [17-21], whereas others do not apply this distinction between the degrees of obstruction in their decision-making [2,4,22-24]. In our own series, the conservative approach was routinely utilized for both the complete as well as the partial obstruction groups. Our data show no significant difference between the complete or partial obstruction groups in terms of management and the resulting morbidity or mortality rates (Table IV). Our success rate of 73% with the conservative treatment of obstruction in our patients contrasts with the recently reported 20% to 62% rates of spontaneous resolution of obstruction (Table VI). When the role and legitimacy of the conservative treatment and careful observation of selected patients with postoperative intestinal obstruction are evaluated, a key issue remains, which is TABLE IV Management and Outcome of 297 Admissions for Complete or Partial Postoperative Adhesion Ileus Complete Partial p Obstruction Obstruction Value Operated 50 (30%) 30 (24%) NS Not operated 116 92 Strangulation 21 (43%) 12 (46%) NS No strangulation 28 14 Alive 163 116 NS Dead 3 (2%) 2 (2%) NS = not significant. the time limit that should be allowed for spontaneous resolution of the obstruction. Some authors accept a limited expectant period of 12 [18] or 24 hours [16] for patients with partial obstruction. However, recent reports suggest a longer time period of 48 to 72 hours [2-4,25,26]. In the present study, the mean period of conservative treatment before surgery was 2 days, with a range from 12 hours to 25 days. That period lasted 5 days or more in 25% of the patients and more than 10 days in THE AMERICAN JOURNAL OF SURGERY VOLUME 165 JANUARY 1993 123

SEROR ET AL TABLE V Effect of Early Versus Late* Operation on Mortality and Bowel Damage in 297 Admissions for Postoperative Adhesion Ileus P Early Late Value Total group (n = 80) Dead 2 (3%) 1 (5%) Live 59 18 N S Strangulated bowel 28 (47%) 5 (28%) Viable bowel 31 13 NS Patients with complete obstruction on admission (n = 50) Dead 2 0 Live 35 13 NS Strangulated bowel 16 (44%) 4 (33%) Viable bowel 20 8 NS NS = not significant. *Late is defined as 5 days or more. TABLE Vl Rates of Strangulation, Operative Intervention, and Mortality in Different Series of Patients With Small Bowel Obstruction Operated Strangulation Mortality References Year No. No. (%) (%) (%) [51 1952 412 297 (72) 22 12 [17] 1962 480 316 (66) 23 11 [22] 1978 238 112 (47) 11 5.5 [25] 1981 405 267 (66) 10 6.7 [18] 1981 52 31 (60) 8 1.9 [23] 1985 127 48 (38) 12 1.5 [16] 1987 311 163 (53) 9 7.7 [3] 1987 75 37 (49) 6.7 1.3 [2] 1987 321 194 (80) 14.3 1 [4] 1989 105 58 (55) 4.7 3.8 (Current) 297 80 (27) 11.1 1.7 12%. It is important to emphasize that a prolonged delay of surgical intervention in these patients did not result in an increased incidence of bowel strangulation or mortality (Table V). As previously mentioned, these findings and results are valid even when the data are analyzed separately for the complete and partial obstruction groups (Table IV). Conservative treatment extending beyond 5 days was never successful, and surgery was inevitable in all the patients whose obstruction did not resolve within 5 days (Figure 1). It should be noted that during the period studied, the socioeconomic and health care environment in Israel did not condemn prolonged hospitalization, and systemsbased cost containment was not part of the surgeons' considerations. We concluded that patients with complete or partial postoperative intestinal obstruction can be managed conservatively provided there are no obvious signs of intestinal strangulation. A conservative trial of up to 5 days' duration offers a safe and reasonable opportunity for spontaneous resolution of the obstruction, as occurred in Figure 1. The resolution of postoperative intestinal obstruction by conservative or operative therapy over the time axis. All patients whose disease responded to conservative therapy had resolution within the first 5 days of treatment. Beyond this point, no patient responded to conservative therapy, and all the remaining patients required surgery. 73% of the patients in our study. A longer period of expectant treatment is unjustified, since the possibility of spontaneous resolution is negligible after 5 days of conservative therapy. Although this conservative approach may seem unjustified in an era of cost containment, we believe that avoiding unnecessary surgery is of great value. REFERENCES 1. Battle WH. Intestinal obstruction coming on four years after the operation of ovariotomy. Lancet 1883; 1: 818-9. 2. Tanphiphat C, Chittmittrapap S, Prasopsunti K. Adhesive small bowel obstruction: a review of 321 cases in a Thai hospital. Am J Surg 1987; 154: 283-7. 3. MeEntee G, Pender D, Mulvin D, et al. Current spectrum of intestinal obstruction. Br J Surg 1987; 74: 976-80. 4. Asbun H J, Pempinello C, Halasz NA. Small bowel obstruction and its management. Int Surg 1989; 74: 23-7. 5. Beeker WF. Acute adhesive ileus. Surg Gynecol Obstet 1952; 95: 472-6. 6. Zadeh B J, David JM, Canizao PC. Small bowel obstruction in the elderly. Am Surg 1985; 51: 470-3. 7. Mucha P Jr. Small intestinal obstruction. Surg Clin North Am 1987; 67: 597-620. 8. Richards WO, William LF Jr. Obstruction of the large and small intestine. Surg Clin North Am 1988; 68: 355-76. 9. Ryan GB, Grobety J, Majno G. Postoperative peritoneal adhesions: a study of the mechanisms. Am J Pathol 1971; 55:117-48. 10. Ellis H. The cause and prevention of postoperative intraperitoheal adhesions. Surg Gynecol Obstet 1971; 133: 1-15. 11. Ellis H. Internal overhealing: the problem of intraperitoneal adhesions. World J Surg 1980; 4: 303-6. 12. Zollinger RM, Kinsey DL. Diagnosis and management of intestinal obstruction. Am Surg 1964; 30: 1-5. 13. Leffall LD, Syphax B. Clinical aids in strangulation intestinal obstruction. Am J Surg 1970; 120: 756-9. 14. Delany HM. Prognostic factors in infarction of the intestine. Surg Gynecol Obstet 1972; 135: 253-65. 15. Shatila All, Chamberlain BE, Webb WR. Current status of diagnosis and management of strangulation obstruction of the small bowel. Am J Surg 1976; 132: 299-303. 16. Brolin RE, Krasna M J, Mast BA. Use of tubes and radiographs in the management of small bowel obstruction. Ann Surg 1987; 124 THE AMERICAN JOURNAL OF SURGERY VOLUME 165 JANUARY 1993

POSTOPERATIVE SMALL BOWEL OBSTRUCTION 206: 126-33. 17. Silen W, Hein MF, Goldman L. Strangulation obstruction of the small intestine. Arch Surg 1962; 85: 137-45. 18. Hofstetter SR. Acute adhesive obstruction of the small intestine. Surg Gynecol Obstet 1981; 152: 141-4. 19. Sarr MG, Bulkley GB, Zuidema GD. Preoperative recognition of intestinal strangulation obstruction. Am J Surg 1983; 145: 176-82. 20. Brolin RE. Partial small bowel obstruction. Surgery 1984; 95: 145-9. 21. Deutsch AA, Eviatar E, Gutman H, Reiss R. Small bowel obstruction: a review of 264 cases and suggestions for management. Postgrad Med J 1989; 65: 463-7. 22. Stewardson RH, Bombeck CT, Nyhus LM. Critical operative management of small bowel obstruction. Ann Surg 1978; 187: 189-93. 23. Wolfson P J, Bauer J J, Gelernt IM, Kreel I, Aufses AH. Use of long tube in the management of patients with small intestinal obstruction due to adhesions. Arch Surg 1985; 120: 1001-6. 24. Cheadle WG, Garr EE, Richardson JD. The importance of early diagnosis of small bowel obstruction. Am Surg 1988; 54: 565-9. 25. Bizer LS, Liebling RW, Delany HM, Gliedman ML. Small bowel obstruction. Surgery 1981; 89: 407-13. 26. Ericksen AS, Krasna M J, Mast BA, Nosher JL, Brolin RE. Use of gastrointestinal contrast studies in obstruction of the small and large bowel. Dis Colon Rectum 1990; 33: 56-64. DISCUSSION Arthur H. Aufses (New York, NY): Were all of the deaths in patients with strangulated bowel, and how did you define strangulation, since there were approximately 30 patients with strangulated bowel, of whom only 19 required resection? Dan Seror: Nineteen of 33 patients required resection, whereas an additional 13 required an enterostomy. Of the patients with bowel obstruction, at least two died of diffuse carcinomatosis. Robert E. Brolin (New Brunswick, N J): The treatment protocol in this study is in great contrast to that followed by many physicians in the treatment of small bowel obstruction. I think it should be reiterated that the incidence of strangulation in the operative group was 40%, which is the highest rate that I've seen in any recently published series on this subject. Could you discuss the high rate of bowel strangulation as related to your conservative treatment of these patients? Were the primary indications for surgery in conservatively treated patients related to the lack of improvement in their condition or to clinical evidence of deterioration? Dan Seror: The total rate of strangulation was only 12% to 13%. The rate of strangulation in the operated group was high because we operated on fewer patients than is commonly accepted. As to the second question, in those patients without evidence of strangulated bowel who underwent operation, the surgeon in charge decided when to operate based on his or her usual policy. However, there was no time limit as to when to operate. Christopher C. Baker (Chapel Hill, NC): Since this is a retrospective study and you had a conservative bias with a nonoperative approach, there are a number of selffulfilling prophecies. Although your data on pulse rate, temperature, and white blood cell count reached statistical significance, the data as I interpreted it had no clinically significant differences. In addition, the data shown concerning the length of hospital stay may result in a self-fulfilling prophecy, since you were trying not to operate. Your data show that operation was inevitable after 5 days, and yet there was at least one patient in whom surgery was delayed 25 days. Have you altered the timing of surgical intervention in patients? Did you analyze the patients who had a nonoperative or operative approach in relation to whether they underwent more than one previous operation? In this country, previous surgery is often a reason not to operate. Finally, could you comment on the incidence of fistulas in your surgically treated patients? Dan Seror: We have no doubts that there is no reason to wait longer than 5 days for an adhesion ileus to resolve spontaneously. The patient in whom we waited 25 days had known diffuse carcinomatosis, and we assiduously tried to avoid surgery in that patient. In patients with recurrent obstruction, we compared the data of our 227 first admissions with the data of our total 297 admissions. The results were the same in both groups for all parameters studied, which led us to conclude that patients with first or recurrent obstructions have similar results. I believe that there were only a few intestinal fistulas. Gregory B. Bulkley (Baltimore, MD): Like the other discussants, I have a number of concerns about your conclusions. Although this was a prospective study, it wasn't really a controlled study, or at least it wasn't randomized. The major benefit of a prospective study results when two groups are created that are comparable. Your data clearly show that the two groups were quite different. For example, there were 28 cases of bowel strangulation in the early operative group and only 5 in the other. Second, your analysis of the various diagnostic tests attempts to determine whether there was a statistically significant difference between the two groups, which is inappropriate when evaluating a diagnostic test. There are alternative approaches: One should calculate sensitivity, specificity, and predictive values, because those are really the questions to be answered. Your data suggest to me that you have shown, as have many other studies, that it's not possible to reliably diagnose strangulation by any single clinical parameter, by any combination of parameters, or by any facile diagnostic test. The decision to conservatively treat a patient with bowel obstruction requires an assessment of the benefits versus the risk of not treating a case of bowel strangulation, and that risk is in the range of 30%. In other words, the predictive value of a nonstrangulated diagnosis has about a 30% chance of being wrong. My reaction to this study is that it shows that your patients are receiving excellent care. Your staff is making appropriate decisions and taking very good care of your patients. However, I regret to say I think that it represents very bad science. THE AMERICAN JOURNAL OF SURGERY VOLUME 165 JANUARY 1993 125

SEROR ET AL Dan Seror: I believe we were able to demonstrate that our conservative approach did not result in a higher rate of bowel strangulation. We had a 12% strangulation rate, which is similar to that found by other studies. I fully agree that the literature in the last 30 years regarding intestinal obstruction has/failed to identify any obvious clinical signs that predict strangulation, as is also the case with our own study. As to your last comment, this is a retrospective study, and I agree that we should be cautious with our conclusions. However, I still think that we have demonstrated convincingly that a very conservative approach, even in patients with complete bowel obstruction, does not result in a higher morbidity rate compared with those patients who undergo surgery within the first 24 hours. 126 THE AMERICAN JOURNAL OF SURGERY VOLUME 165 JANUARY 1993