Hidden Inferior Vena Cava Injury: A Case of Missed Diagnosis after Preoperative CT and Laparotomy

Introduction

Inferior vena cava (IVC) injury is a potentially fatal injury with a high mortality rate of 34–70% [1]. Generally, IVC injury can be easily diagnosed based on the presence of a massive retroperitoneal hematoma or extensive bleeding during emergency laparotomy [2]. In cases in which the patient’s condition is stable, diagnosis by computed tomography (CT) is the criterion standard [3]. Since the IVC is a vein, it is necessary to check for leakage of contrast medium in the late phase on CT angiography (CTA). Findings on CTA include retroperitoneal hematoma around the IVC, extravasation of contrast medium, and abnormal morphology of the IVC [3]. Here, we report the case of an IVC injury that could not be diagnosed by preoperative CTA examination and could not be immediately detected during laparotomy.

Case Report

A 73-year-old woman had cut her neck and stabbed her abdomen with a knife. The weapon used was a sashimi knife with a blade length of approximately 30 cm. Her family found her lying on her back and called for emergency help. She arrived at our hospital approximately 45 min later. She had a history of Parkinson’s disease and hypertension, but no history of depression. She was not taking any anticoagulants.

Her vital signs on admission were: Glasgow Coma Scale score of 8 (E2V2M4), body temperature 36.3°C, heart rate 112 beats/min, blood pressure 75/50 mmHg, and oxygen saturation 98% (10 L/min via O2 mask). There was a cut approximately 15 cm long on her neck. Although no air leak or pulsating mass was visible, there was persistent bleeding, which appeared to be due to venous injury. This bleeding could be stopped by compression. There was a puncture wound measuring approximately 5 cm long in the midline of the upper abdomen, and the omentum and transverse colon had prolapsed. There was no active bleeding from the abdomen. Her extremities were cold. There was an approximately 4-cm-long incision on her right forearm, but the subcutaneous tissue was not visible. Blood tests showed a hemoglobin level of 10.0 g/dL, indicating anemia. In addition, the lactate level was 3.7 mmol/L, confirming an increased lactate level. Focused Assessment with Sonography for Trauma (FAST) found no collection of intraperitoneal fluid. Emergency CTA (CANON MEDICAL SYSTEMS Corporation, Tochigi, Japan) showed that the contrast effect of the major blood vessels in the neck was maintained. Slight damage to the thyroid and larynx was noted (Figure 1). Abdominal contrast examination confirmed prolapse of the omentum and transverse colon out of the abdominal cavity in the midline of the lower abdomen. Irregularity in the stomach wall and free air in the abdominal cavity were apparent. A small amount of fluid was observed around the spleen and in the pouch of Douglas, but there was no obvious extravasation.

The IVC was round, with no obvious morphological abnormalities. There was no retroperitoneal hematoma (Figures 2, 3). Treatment course: On arrival at our hospital, the patient was in hemorrhagic shock, and massive blood transfusion was started using a massive transfusion protocol (MTP). Bleeding from the neck was suspected to be the cause of the shock because FAST was negative, CTA showed little fluid accumulation in the abdominal cavity, and there was no persistent bleeding from the abdominal puncture wound. We immediately consulted an otorhinolaryngologist, who performed hemostasis and irrigation drainage in the primary treatment room. Since no damage to the carotid artery and vein was observed, the bleeding from the neck wound was stopped by applying pressure with gauze. The wound was left open for daily washing. After treatment of the neck wound was completed, approximately 90 min after the patient had arrived at the hospital, laparotomy was performed for the abdominal puncture wound. The surgery was performed under general anesthesia. The left and right subdiaphragmatic areas, the left and right paracolic grooves, and the pouch of Douglas were checked. Only 50 mL of blood was observed in the abdominal cavity. No hepatic or splenic damage was observed. Food residue was found on the outside of the stomach, and examination showed a gastric injury, approximately 3 cm long from the anterior wall to the posterior wall. No retroperitoneal hematoma suggestive of pancreatic injury or bilateral renal injury was observed. After suturing and repairing the gastric injury, the entire gastrointestinal tract was re-examined to check for any additional organ injuries. An approximately 3-cm-long wound was observed in the avascular field of the transverse mesentery and was closed with sutures. At that time, the surrounding area was examined, but no obvious hematoma was observed. The intestine was moved aside to investigate the entry path of the knife, and an approximately 1-cm incision was found in the retroperitoneum at the mesenteric root, about 5 cm caudal to the ligament of Treitz. Suddenly, a large amount of bleeding was observed from the same site. The injury site in the retroperitoneum was confirmed while performing compression hemostasis. An injury to the IVC was observed caudal to the right renal vein inflow site (Figure 4). The bleeding likely occurred because moving the intestine removed the packing effect it had provided.

The IVC was controlled by manual hemostasis and by blocking the proximal and distal parts of the injury. The bleeding was successfully stopped by manual hemostasis. This allowed us to inform the anesthesiologist about the possibility of an IVC injury and make adequate preparations for blood transfusion and other interventions. Thereafter, the area around the IVC was sufficiently dissected and then side-clamped with vascular clamps. No significant drop in blood pressure was observed intraoperatively, and no obvious damage to the posterior wall of the IVC was observed. The injured area was sutured with 6-0 non-absorbable suture. There was slight stenosis in the IVC after repair. Because the patient had received a large blood transfusion due to hemorrhagic shock (26 units of red blood cells and 26 U of fresh-frozen plasma), open abdomen management was performed for the first surgery. Postoperatively, the patient’s vital signs, blood test data, and intra-abdominal pressure (IAP) showed no abnormalities, and her overall condition was assessed as good. The abdominal wound was closed on the 2nd day after her injuries because there was no rebleeding. The neck wound was closed on the 6th day after her injuries. Tracheostomy was performed because swallowing function had deteriorated due to the neck injury. Due to possible suicidal ideation before admission, we consulted a psychiatrist during the patient’s hospitalization, and she was diagnosed with depression. The patient was transferred to the psychiatry department on the 28th day after her injuries for evaluation and treatment for depression. She was discharged from our hospital on the 65th day after her injuries.

Discussion

IVC injuries are typically identified by CTA or become apparent during surgery, but an unusual IVC injury that did not fit either of these scenarios was presented [3]. Most IVC injuries, approximately 85–95%, are caused by penetrating injury [4]. Another report found that gunshot wounds accounted for 71% and stab wounds accounted for 29% of IVC injuries [5]. Computed tomography is useful for diagnosing IVC injuries [3]. In cases in which CT cannot be performed, the diagnosis may be easily made based on the presence of a massive retroperitoneal hematoma or extensive bleeding at the start of emergency laparotomy [2]. However, in the present case, the diagnosis could not be made from the preoperative CT examination, and the IVC injury could not be immediately identified during laparotomy. A possible reason for this could be that the central venous pressure had decreased significantly, and bleeding was controlled solely due to packing by the intestinal loops [6,7]. The absence of any bleeding during laparotomy may have been a result of the decrease in IVC pressure due to bleeding from the neck injury and the natural packing of the injury with intestinal loops. In addition, the IVC injury may not have been detected on CTA due to a similar mechanism.

Preoperative abdominal contrast-enhanced CT showed no obvious evidence of IVC injury, and it was only discovered when the entry path of the knife was re-examined during laparotomy. Computed tomography is generally a useful and reliable examination for identifying IVC injuries [3]. However, if there is an injury in the midline of the abdomen due to a stab wound, gunshot wound, or other injury mechanism that has a high risk of damaging the IVC, possible injury to the IVC should be kept in mind. If there is heavy bleeding from wounds to other parts of the body, such as the neck, as in the present case, the source of the bleeding from the IVC injury may not be immediately apparent.

It is important to search for the route of injury in abdominal stab wounds including IVC injury, even if there is no IVC injury visible on CTA, massive intraoperative intra-abdominal hemorrhage, or a huge retroperitoneal hematoma. The possibility of IVC injury should also be included in the differential diagnosis, especially in patients presenting with multiple penetrating injuries to the abdomen.

Conclusions

CTA is highly effective in diagnosing IVC injury, but IVC injury may be difficult to detect when patients have severe trauma causing hemorrhagic shock.