Presentation
Undergoing open-heart surgery for mitral valve replacement. During instrument count at the end of surgery, a small metallic nozzle of the suction apparatus is not found.
Patient Data
Peroperative X-Ray, A/P Supine
The left-behind metallic nozzle is indeed identified within the chest, superimposed over the heart shadow and left pulmonary hilar region, several centimeters above the level of the prosthetic mitral valve. The surgical team actually had to place another nozzle over the chest wall to act as a reference to help identify the lost nozzle. Without the reference, it may be quite difficult to identify the lost device among so many other devices and tubes.
Tip of the nasogastric tube is located a few centimeters above the level of the diaphragm. A Swan-Ganz catheter is placed to measure intra-atrial pressure as well as for infusions.
2nd post-operative day
The lost nozzle seems to have migrated vertically downwards, without any lateral displacement. The supine lateral xray shows that it is near the posterior or dependent part of the thorax and far away from the prosthetic mitral valve.
Despite the beam-hardening artefacts created by the metallic nozzle and the mitral prosthesis, the lost nozzle is still identifiable as located in the dependent within the chamber of the left atrium, and not within or outside the pericardial space.
There is no leakage of contrast beyond the cardiac chambers, and there is only minimal pericardial effusion, which excludes the possibility that the metallic nozzle could perforate through the heart walls or pericardium.
The left atrium itself is hugely enlarged, due to the dysfunctional mitral valve, which has now been replaced by the prosthesis.
The chest and heart had to be reopened in a repeat surgery under general anesthesia, and the lost nozzle was recovered from the chamber of the left atrium.
Case Discussion
The per-operative xray revealed that the missing nozzle of the suction tube was indeed within the chest cavity, but xrays obviously cannot reveal the exact location of the item, i.e. within or outside the cardiac chambers v/s within or outside the pericardial space v/s whether it was impacted or perforated through any tissue. In this situation, and since the heart and pericardium had already been sutured closed, the surgical team decided to postpone the recovery of the nozzle until identifying its exact location by further imaging. This situation is known as a "retained surgical foreign body", where the recovery of a missing surgical item is postponed or abandoned in favor of a repeat procedure later on 1,2.
The post-operative supine A/P and lateral xrays did not provide much additional information, other than that the nozzle far away from the mitral prosthesis. Contrast-enhanced CT provided the complete anatomical location of the nozzle, i.e. within the chamber of the left atrium and without any impaction or perforation, and then it was recovered in a subsequent repeat surgery involving reopening of the sternotomy, pericardiotomy and myocardiotomy sutures.
Retained surgical foreign body (RSFB) is classified as an "almost never event", which means that such an occurrence should "almost never" happen if already known and available precautions are properly followed 1,3.