Ultrasound-guided Removal of Retained Soft Tissue Foreign Body with Late Presentation.

Foreign body (FB) removal represents a large part of the work in surgical practice.[1] However, FB removal may often be a surgical challenge because of the nonpalpated and close anatomical relationship of the FB to vital structures or due to patients with cicatricial diathesis.[2] Retained FBs may result in infection, chronic pain, structural injury, granuloma, and psychological distress, especially with late presentation (more than 1 week from the time of injury).[13]

Between December 2011 and February 2016, 12 consecutive patients with retained FBs were examined at our department. They were 8 men and 4 women, aged 10–68 years (mean age, 42.7 years). Indications for ultrasound-guided FB removal were as follows: FB was retained in the soft tissue for various reasons; the FB was visible on ultrasound with an apparent safe-guided access;[2] the FB was located in the subcutaneous soft tissue a distance of <30 mm from the skin; and the patient did not want the FB to be surgically removed or patient was with cicatricial diathesis.

The FBs included one cactus needle, one jujube thorn, a metal fragment, and one shard of glass, and the remaining eight were all wooden splinters. Small FBs were retained in the various areas of the body, including four fingers, two feet, two calves, one palm, one forearm, one back, and one ankle. The pretherapeutic duration was from 2 weeks to 1.5 years. Two patients underwent surgical exploration without the use of ultrasound examination to detect the FB before, and the outcome turned to be a failure. The remaining ten patients presented to our department complaining of a persistent FB sensation without previous treatment. The distance between the FBs and the skin was 8.8 mm (range: 3–23 mm). The largest diameter of FB was 11.9 mm (range: 4–25 mm).

All FB removal procedures were performed under real-time ultrasound guidance by one radiologist with >10 years of experience in interventional radiology. The technique described below was used for all patients in the outpatient clinic. The area around the wound was sterilized and the probe was sheathed or sterilized. After careful ultrasound examination, the size of the FB and its exact location, depth, three-dimensional orientation, and relationship to other structures were recorded, and the skin was marked accordingly. A small incision (usually 2–3 mm) was made at the point of nearest long axis of the FB (skin marking). Through the incision, ophthalmologic forceps arrived at the tip of the FB in the same plane (long-axis view). Then, the probe turned to the short-axis view to show the relationship between the forceps and FB [Figure 1]. The arms of the forceps were then opened to grasp the FB and remove it. All the procedures were performed freehand by the same radiologist.

Figure 1

A 10-year-old boy fell into a ditch 2 weeks before presenting at our hospital. Initially after the wooden splinter was removed, the wound healed. However, the patient still felt discomfort and received an ultrasound examination. (a) Transverse sonogram showing a foreign body (arrows) with posterior acoustic shadowing in the subcutaneous soft tissue layer. (b) After confirmation, the foreign body was removed under ultrasound guidance. The surgical forceps were inserted through the incision (crocodile forceps) and reached the foreign body in-plane.

In 11/12 patients, the FBs were successfully removed under ultrasound guidance, and the procedure took from 15 to 30 min (mean, 21.6 min). There was only one failure to remove the FB, which was in a male with a wood thorn that had penetrated into the thenar muscles. The distance between the FB and the skin was 23 mm, which was deeper than those successful cases (mean: 7.5 mm, range: 3–16 mm). The patient was then referred to a surgeon and surgical exploration was successful. All patients were discharged on the same day of the procedure. The FB removal procedure was well tolerated by all patients. No procedural-related complications occurred. After a mean follow-up of 22.4 months (9–39 months), no patients had discomfort at the site where the FB was removed.

In conclusion, the ultrasound-guided soft tissue FB removal is a safe and minimally invasive technique. It is worthwhile to promote the use of ultrasound-guided FB removal, even with late presentation.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

This work was supported by a grant from the Hospital Clinical Key Project of Peking University Third Hospital (No. 75502-02).

Conflicts of interest

There are no conflicts of interest.