Ultrasound-guided removal of a splenic foreign body in a dog

Abstract

A 10-year-old spayed female bull terrier was brought to a veterinary referral center with abdominal pain. An abdominal ultrasound and CT scan identified a foreign body in the spleen. The object was removed via an ultrasound-guided procedure using Hartmann foreign-body forceps, avoiding the need for laparotomy. The procedure was uncomplicated. The animal was discharged after 24 h of inpatient monitoring and repeated ultrasound examinations. The dog was in good general condition 2 mo after the procedure, with no recurrence of clinical signs. To the best of the authors’ knowledge, this is the first reported case of ultrasound-guided removal of a splenic foreign body in a dog.

Key clinical message:

Ultrasound-guided removal is an alternative method to remove splenic foreign bodies in dogs that is quick to perform and minimally invasive.

Abdominal extra-digestive foreign bodies are uncommon in dogs (1–4). The soft-tissue foreign bodies most commonly described in the literature are of plant origin (5,6). Splenic foreign bodies are rare and can be associated with complications such as septic peritonitis (3,4,7). Ultrasonography is recognized as specific and sensitive for detecting foreign bodies in human soft tissues (8). In this case, we present the diagnosis and treatment of a dog with a splenic foreign body: a toothpick.

CASE DESCRIPTION

A 10-year-old spayed female bull terrier weighing 15 kg was referred because of acute abdominal pain and lethargy accompanied by a swelling of the left abdominal flank. The swelling had appeared ~1 mo earlier and was clinically and spontaneously resolved within 24 h. However, a recent recurrence had been observed, lasting for 4 d and prompting a referral. Clinical examination revealed hyperthermia (rectal temperature: 39.4°C) and acute pain on palpation of the abdomen. The rest of the examination was within normal limits.

Abdominal ultrasound examination revealed a linear, hyperechoic structure projecting an acoustic shadow distally (Figures 1, 2), 3.8 mm in diameter and 6 cm in length. This element crossed the body of the spleen over a length of ~3 cm and extended craniolaterally into the left abdominal muscular wall. In its caudal portion, it protruded from the splenic parenchyma into the peritoneal cavity. A hyperechogenicity of the peritoneal fat immediately adjacent to the foreign body was noted.

FIGURE 1.

Ultrasound image showing a linear, hyperechoic structure generating free shadow cones corresponding to the toothpick (T) perforating the splenic parenchyma (S) of a dog (longitudinal view). A swelling and hyperechogenicity of the peritoneal fat immediately adjacent to the foreign body are observed. Perisplenic and left cranial abdominal fat are diffusely hyperechoic, with no detectable fluid collection. The left abdominal muscle wall is locally swollen and hypoechoic.

FIGURE 2.

Ultrasound image showing a hyperechoic spot projecting an acoustic shadow distally, representing the toothpick (T) in the splenic parenchyma (S) of a dog (transverse view).

Perisplenic and left cranial abdominal fat were diffusely hyperechoic, with no detectable fluid collection. The left abdominal muscle wall adjacent to the spleen was locally hypoechoic. Ultrasound examination facilitated diagnosis of a foreign body of mixed localization (peritoneal, splenic, and left peritoneal wall) with signs of surrounding peritonitis and no collected abscess.

Removal of the foreign body using a minimally invasive, ultrasound-guided method was discussed with the owners. A minimally invasive approach was considered possible due to the proximity of the foreign body to the body wall and the lack of evidence to suggest septic peritonitis or local abscess formation. The owners were advised about the risks of failure and induced hemorrhage, implying the need for laparotomy.

In anticipation of these risks, coagulation times were measured and determined to be within the reference ranges [PT: 12 s (range: 15 to 22 s), apTT: 94 s (range: 65 to 119 s)]. In anticipation of anesthesia and CT scan, serum creatinine, total protein, and hematocrit were also evaluated and were normal [TP: 84 g/L (range: 65 to 75 g/L), creatinine: 9.2 mg/dL (reference: < 12 mg/dL), hematocrit: 40% (range: 35 to 55%)]. The dog was sedated with morphine hydrochloride (Morphine Cooper; Lavoisier, Melun, France) at a dose of 0.1 mg/kg body weight, IV. Anesthesia was then induced with a combination of alfaxalone (Alfaxan; Jurox, Rutherford, NSW, Australia) at a dose of 2 mg/kg body weight; and diazepam (Diazepam; TVM, Lempdes, France) at a dose of 0.25 mg/kg body weight, IV. Anesthesia was maintained using isoflurane after endotracheal intubation (Isoflo; Abbott Animal Health, Maidenhead, UK).

Parameters monitored during anesthesia included heart rate, respiratory rate, oxygen saturation, capnography, and electrocardiography. An IV infusion of Ringer’s lactate solution (Ringer’s Lactate; Bayer, Leverkusen, Germany) was administered at a rate of 5 mL/kg body weight per hour.

A thoracic and abdominal CT scan was used (Figure 3) to further assess the foreign body. It revealed a hyperattenuating linear structure through the splenic parenchyma, with peritoneal extension, relatively distant from the surrounding vessels. The CT scan showed no evidence of splenic inflammation, hematoma, or infarction. The muscular and subcutaneous tissues adjacent to the spleen showed thickening and hyperattenuation, but the foreign element was not visualized in this region, indicating its probable displacement between the ultrasound and CT scan. The CT scan confirmed the presence of an intrasplenic and peritoneal foreign body with signs of relatively moderate focal peritoneal, muscular, and subcutaneous inflammation (Figures 3, 4, 5).

FIGURE 3.

Computed tomographic reconstruction of the abdomen in the left parasagittal section shows a linear, hyperattenuating structure in the splenic (S) parenchyma of a dog, corresponding to the toothpick (T).

FIGURE 4.

Contrast-enhanced CT scan reconstruction of the abdomen in the coronal section shows the long splenic foreign body (arrow) passing through the spleen (S) and over the projection area of the left kidney (K) in a dog.

FIGURE 5.

Computed tomographic image of the abdomen in cross section shows a discreetly hyperattenuating element lateral to the body of the spleen (S) in a dog.

The optimal incision site was determined using the results of CT and ultrasonographic examination. The area was surgically prepared, and a skin incision of ~3 mm was made, using a No. 11 scalpel blade, in the left ventral craniolateral abdominal region.

Hartmann alligator forceps were then inserted and introduced intramuscularly into the abdomen. Ultrasound guidance was used to direct the forceps toward the foreign body. The foreign body was grasped at one end, with the forceps and foreign body parallel. Firm traction was applied, enabling the foreign body to be removed via the small skin excision. The foreign body was confirmed to be a toothpick. Following the removal, an ultrasound evaluation was made to assess for hemorrhage and was repeated 15 min later. These examinations revealed neither evidence of abdominal hemorrhage nor remnants of the foreign body. Cutaneous disinfection was then undertaken with chlorhexidine solution, followed by closure of the 3-millimeter incision with a staple. Mucosal color was monitored hourly for 6 h, and general condition was observed throughout the hospitalization period.

No intra- or postoperative incidents were observed. Antibiotic treatment was prescribed (amoxicillin, clavulanic acid) at a dosage of 20 mg/kg, PO, q12h immediately after surgery, and maintained for 7 d. Two months after the procedure, the dog was in good general condition, with no recurrence of clinical signs and no lesions identified on ultrasonography.

DISCUSSION

To the authors’ best knowledge, the presence of a toothpick perforating the spleen in a dog has only been described once in the literature (4). Dogs may accidentally ingest toothpicks embedded in food, so the digestive route is considered more likely than the transcutaneous route. The absence of skin lesions in the described case supported this hypothesis. Several studies have reported cases of abdominal foreign bodies accompanied by gastric perforation, which can subsequently lead to peritonitis (4,9–12). However, in our case, no lesions of the gastrointestinal tract were detected on ultrasound examination or CT scan. If a foreign body passes through the gastrointestinal tract, aerobic and anaerobic peritoneal bacterial contamination is possible (13). Several studies have suggested the need for splenectomies in cases of splenic foreign bodies, both in cats and humans (7,14,15). Two other studies in dogs demonstrated that surgical removal of a perforating foreign body can be achieved without the need for splenectomy, and that resolution of the associated peritonitis can be expected, as in our case (3,4). Yet, it is crucial that clinical decisions are based on the specific details of each individual case.

Intraoperative ultrasonography and laparoscopy are used to facilitate the surgical removal of foreign bodies (2,6,16,17). Surgical removal is an invasive procedure and can be technically complex, sometimes requiring a large skin and muscle incision. The procedure can fail or involve complications such as inadequate visualization of the foreign body, hemorrhage or laceration of splenic parenchyma, loss of the foreign body into the abdominal cavity, and presence of adhesions between organs over the area of interest (2).

The technique used in this case is minimally invasive and provides real-time guidance to locate and remove the foreign body precisely, minimizing the risk of bleeding and damage to surrounding structures. Moreover, a failure of ultrasound-guided removal does not preclude subsequent surgical management if necessary. However, it is important to note that the main limitation with this approach is the inability to explore the abdomen — particularly the gastrointestinal tract, which is presumably the foreign body’s original source. Even without evidence of peritonitis, a small perforation could still be missed.

Radiography and CT are effective in detecting radiopaque foreign bodies. In our case, CT was particularly useful, enabling more precise visualization of the foreign body and ensuring the absence of other abdominal lesions. According to a recent meta-analysis, ultrasonography has a specificity of 92% and a more moderate sensitivity of 72% for detecting foreign bodies in humans (8). However, from the same study, when ultrasound examination detects radiopaque or wooden foreign bodies, sensitivity increases considerably, reaching 96.7%. Specificity decreases moderately, to 84.2%. In human medicine, a decrease in the diagnostic sensitivity of ultrasonography was reported when foreign bodies were located at a depth > 2 cm (18,19).

In conclusion, to the authors’ best knowledge, this case report provides the first description of ultrasound-guided, percutaneous removal of an intrasplenic foreign body in a dog. This technique represents a new method for removing previously identified intrasplenic foreign bodies. It is minimally invasive and quick to perform. CVJ