Case Nº1 - FJM

A 60-year-old man presented to the emergency department for evaluation of rectal

bleeding, syncope, and pain in the right leg. Five days earlier, diffuse abdominal pain

that worsened with movement had developed in association with nausea, anorexia,

and malaise. He had not traveled recently or ingested any unusual foods, and he had

no history of fever, weight loss, or change in bowel habits. Approximately six hours

before admission, he had a single episode of gross hematochezia and hematuria followed by syncope. Soon after, he began to have intense pain in his right leg, and he

sought medical care.

The patient had a two-year history of chronic diarrhea, without bleeding. One year

before his presentation he had undergone a colonoscopy, which showed diverticulosis

and two polyps. The polyps were excised and proved to be benign. The results of

an upper gastrointestinal series with small-bowel follow-through and endoscopy

performed at that time were normal. Empirical treatment with metronidazole for

possible giardiasis and hyoscyamine for possible irritable bowel syndrome were minimally effective in controlling the symptoms.

The patient also had a history of hypertension, hyperlipidemia, and gout. His medications included atenolol (50 mg daily), atorvastatin (20 mg daily), allopurinol (300 mg daily), and aspirin (81 mg daily). His father had died of colon cancer at an advanced age. The patient had a remote history of alcohol abuse, but he reported no alcohol intake for the past 20 years. He had a 100 pack-year smoking history but had recently quit.

On physical examination, the patient appeared alert but in moderate distress. He appeared obese; he weighed 108.4 kg, was 175 cm tall, and had a body-mass index (the weight in kilograms divided by the square of the height in meters) of 35.4. He was afebrile; the blood pressure was 74/40 mm Hg, and the heart rate 72 beats per minute. The oxygen saturation level was 98 percent while the patient was breathing ambient air. He was edentulous, wore dentures, and had dry mucosa. Cardiac examination revealed a regular rate and rhythm, without murmur or gallop. There was no jugular venous distention, and no bruits were present. The abdomen was diffusely tender, but there was no guarding, pulsatile mass, or rebound tenderness. The bowel sounds were normal. The rectal examination revealed normal sphincter tone and gross blood, but no tenderness or mass. The legs were nontender; both legs were considered to be warm, but the right leg had diminished pulses as compared with the left. The neurologic examination revealed no focal deficits.

The white-cell count was 16,100 per cubic millimeter, with 87 percent neutrophils and 7 percent band forms. The hemoglobin level was 12.7 g per deciliter, with a normal mean corpuscular volume. The platelet count was 85,000 per cubic millimeter. The serum creatinine level was 1.4 mg per deciliter (123.8 μmol per liter), and the level of urea nitrogen was 34 mg per deciliter (12.1 mmol per liter). The electrolyte levels were normal, and the bicarbonate level was 27 mmol per liter. The prothrombin time was prolonged, at 16.2 seconds (international normalized ratio, 1.8), and the partial- thromboplastin time was normal (31 seconds). The erythrocyte sedimentation rate was 57 mm per hour. Amylase and lipase levels were normal, and the results of liver-function studies were normal, except for an albumin level of 2.6 g per deciliter. No blood smear was obtained. Urinalysis demonstrated the presence of blood (3+), with 2 to 4 red cells, 2 to 4 white cells, and 1+ granular casts per high-power field.

A radiograph of the chest showed no acute disease, and abdominal radiographs demonstrated no obstruction, free air, or stones. The electrocardiogram was normal. Computed tomography (CT) of the abdomen and pelvis revealed an area of sigmoid diverticulosis, thickening of the wall of the sigmoid colon, and a peripherally calcified right iliac artery with infiltration of the surrounding fat.

Blood cultures were obtained, and empirical antibiotic therapy with levofloxacin, metronidazole, and gentamicin was begun, as was vigorous intravenous administration of fluids. Initially, there was transient hemodynamic improvement, but the patient then had another episode of hematochezia followed by syncope, with a fall in blood pressure

to 69/41 mm Hg. A second complete blood count obtained within several hours after the initial assessment revealed that the hemoglobin level had fallen to 7.6 g per deciliter and the platelet count had declined to 55,000 per cubic millimeter. The pain in the patient’s right leg worsened, and his right foot was cooler than the left. Specialists from both general and vascular surgery were consulted.

Packed red cells, fresh-frozen plasma, and platelets were administered. The blood pressure increased to 134/80 mm Hg, but the prothrombin time remained elevated. Duplex ultrasonography revealed no flow in the right common femoral artery and absent systolic pressures in the right ankle. Technetium-99m scintigraphy demonstrated active bleeding in the rectosigmoid colon.

¿What diagnostic test is the most appropiate?¿What is the diagnosis?

The patient was taken to the operating room. Laparotomy revealed diverticulosis and extensive calcification of the aorta and iliac vessels. Further exploration revealed a thin, solid foreign body perforating the rectosigmoid junction into the right

external iliac artery, producing extensive hemorrhage and thrombus in the colon and vessel. Arteriotomy and thromboembolectomy were performed, but stool contamination of the field prevented graft placement during the arterial repair. The iliac laceration was closed; intraoperative Doppler study showed a slight signal distal to the repair, suggesting only minimal improvement in vascular flow. Sigmoid colectomy with colostomy formation was performed without complications. Blood cultures grew Clostridium ramosum and C. cadaveris. Pathological examination revealed

colonic inflammatory changes, diverticulosis with a perforated diverticulum, and a wooden toothpick, 5.8 by 0.3 cm. The postoperative course was complicated by persistent pain and ischemia in the right leg. Additional revascularization procedures were avoided because of the possibility of infection and irreversible ischemic damage. The development of gangrene resulted in a below-theknee amputation on the sixth postoperative day, which required revision to an above-the-knee amputation 20 days later because of poor wound healing. The patient returned home one week after this surgery, without further complications. The patient did not recall ever chewing or ingesting a toothpick

Perforations of the gastrointestinal tract by ingested toothpicks are rare, with an annual rate of 0.2 per 100,000 persons.1 Of foreign-body ingestions, however, toothpicks have been reported to have the highest rate of impaction and perforation

(9 percent).2 These small, thin, and indigestible foreign bodies have at least one sharply pointed end, and their length makes it difficult for them to traverse the tortuous intestinal lumen.3 Perforations have occurred throughout the gastrointestinal

tract, including the duodenum, jejunum, cecum, sigmoid colon, appendix, and a Meckel’s diverticulum,4 with complications including abscess formation, sepsis, hemorrhage, and perforations of major vessels resulting in death.5-9 This patient had a major arterial perforation complicated by sepsis and limb gangrene that eventually necessitated amputation. The timely

identification and treatment of toothpick perforations are warranted; however, the diagnosis remains challenging, since patients may be unable to recall ingesting a toothpick, the symptoms of the condition may mimic those of other disorders,

and a toothpick is difficult to identify radiographically. This patient had no recollection of chewing or swallowing a toothpick, and such a response is not uncommon. Among a series of patients found to have toothpick ingestion, only 12 percent

were aware that it had occurred.10 Many affected patients have altered oral sensation or awareness owing to dentures, the use of alcohol, or underlying psychiatric illness.1 Accidental ingestion has also been reported in competent adults, especially

in those who habitually chew toothpicks, although this patient denied this practice.9 His use of dentures was his only risk factor. The symptoms and signs associated with toothpick perforation are similar to those of several intraabdominal diseases, including diverticulitis, appendicitis, renal colic, and inflammatory bowel disease.10-12 Because of this patient’s history of

diverticular disease and symptoms of anorexia, malaise, and nausea, his physicians initially suspected diverticulitis. The addition of ischemia of the right leg and rectal bleeding to the abdomi-nal pain was key in diagnosing the arterioenteric

fistula, since this provided a single unifying explanation for this patient’s unusual presentation. Although the operative note did not clearly identify the cause of hematuria, it may have been related to associated ureteral inflammation.

Because of their radiolucency, toothpicks are difficult to image. In a series of 57 patients who ingested toothpicks, these foreign bodies were visualized by ultrasonography, CT, and radiography in only 14 percent.10 The definitive diagnosis

of toothpick perforation was most commonly made by laparotomy (53 percent) or by endoscopy (19 percent).10

In the case under discussion, the brisk bleeding and other factors contraindicated colonoscopy. Although the sensitivity and specificity of nuclear scintigraphy are generally suboptimal (85 percent and 70 percent, respectively),13 the technique

in this case successfully identified the bleeding site, allowing for prompt and definitive surgical intervention. Laparotomy confirmed the perforation of the sigmoid colon by the toothpick, with penetration of the right external iliac artery.

Diverticulosis has been noted to be a predisposing factor for perforation.14 Given the evidence of diverticular perforation on pathological examination, it is likely that this patient’s toothpick lodged in a sigmoid diverticulum and was forced by peristalsis to make a sharp right turn, resulting in penetration of the mucosa and the right external iliac artery and, ultimately, an arterial

fistula. The unfortunate combination of preexisting peripheral vascular disease with trauma, hemorrhage, and subsequent infection resulted in unsalvageable ischemic changes that eventuated in gangrene and amputation.