139 CT Diagnosis of Occult Incisional Hernias Gary G. Ghahremani1 Miguel A. Jimenez Mark Rosenfeld David Rochester Received July 10, 1 986; accepted after revision August 21 , 1986. Presented at the annual meeting of the American Roentgen Ray Society, Washington DC, April 1986. I All authors: Department of Diagnostic Radiol- ogy, Evanston Hospital-Northwestern University McGaw Medical Center, 2650 Ridge Ave., Evans- ton, IL 60201 . Address reprint requests to G. G. Ghahremani. AJR 148:139-142, January 1987 0361-803X/87/1481-0139 C American Roentgen Ray Society CT of the abdomen was performed on 14 adult patients 2-25 months after laparotomy in order to evaluate intraabdominal processes. Clinically unsuspected incisional hernias were detected in all cases. These herniations were not disclosed by previous physical examination because of the patients’ obesity, abdominal pain, distension, or various other factors. However, CT scans showed the exact size, location, and content of each incisional hernia. The evaluation of postsurgical abdomen by CT should include a careful assessment of previous laparotomy sites in search of occult incisional hernias that may be the source of the patient’s abdominal symptoms. Incisional hernias are delayed complications of abdominal surgery and occur in 0.5-1 3.9% of patients according to various reported series [1 -3]. The average frequency is currently about 4%, but these iatrogenic hernias constitute a significant problem, given that almost 2 million abdominal operations are performed in the United States each year [4, 5]. Most incisional hernias are easily recognized by careful inspection and palpation. However, there are several situations whereby an accurate clinical diagnosis may be difficult or impossible. In obese patients, for example, the abundant subcuta- neous fat can prevent the palpation of a deeply seated peritoneal defect and the protruding intestinal loop or greater omentum. The detection of an incisional hernia by physical examination alone may also be difficult in patients with abdominal pain and distension or in the presence of keloid or thick panniculus. Furthermore, the herniated segments occasionally dissect and hide between muscular, aponeurotic, and fascial layers of the abdominal wall. These interpanetal or interstitial hernias often present with localized swelling and tenderness adjacent to the surgical scar, but their actual content and internal orifice are seldom palpable [6]. Under these circumstances, evaluation of the abdominal wall by sonography or CT can provide the correct diagnosis as illustrated in a few case reports [5, 7-1 0]. This article describes our experience with 14 adult patients whose postoperative CT of the abdomen showed clinically occult incisional hernias of various size, location, and content. Materials and Methods This series includes four men and 1 0 women, ranging in age from 25 to 86 years (average, 57 years). They were evaluated at our institution over a 7Y2-year period between August 1978 and February 1 986. All had nonpalpable incisional hernias that were first recognized on postoperative CT of the abdomen and pelvis. These scans were obtained primarily for follow- up of gynecologic malignancies (five cases) or colon carcinoma (three cases). Six others were examined because of abdominal symptoms after laparotomy for ulcerative colitis, lymphoma, diverticulitis of the colon, cholecystitis, aortic aneurysm, and internal injuries due to numerous stab wounds (one case of each). Two of our patients had undergone surgery twice and one had had three laparotomies. Downloaded from www.ajronline.org by 52.73.204.196 on 05/16/22 from IP address 52.73.204.196. Copyright ARRS. For personal use only; all rights reserved