Major vascular injury is a relatively infrequent complication during lumbar disc surgery with the incidence of 2.4% of lumbar laminectomies and the mortality rates ranging from 40 to 100% [1]. High mortality rates are attributed to rapid blood loss into the retroperitoneal space and difficulties in recognizing the cause of deterioration. Since such cases always require emergency treatment, it is essential for anaesthesiologists to be aware of this potential complication.

We present a case of a 25-year-old woman who sustained iliac artery injury during lumbar microdiscectomy that was diagnosed by computed tomography and treated by laparotomy.

CASE REPORT

A 25-year-old woman (52 kg, 160 cm) with symptoms of low back pain radiating to the left lower limb, was admitted for L4-L5 microdiscectomy. Her medical history was significant only for an allergy to fur and varicose veins of lower limbs. Haemoglobin concentration was 8.6 mmol L-1. The patient was premedicated with oral midazolam 0.3 mg kg-1 40 min before the induction of anaesthesia. Routine monitoring consisted of electrocardiogram, pulse oximetry, end-tidal CO2, non-invasive blood pressure; neuromuscular block was initiated on arrival to the operating room.

After preoxygenation, anaesthesia was induced with propofol 1.5 mg kg-1 iv, fentanyl 2 µg kg-1 iv Moreover, vecuronium 0.12 mg kg-1 iv was administered to facilitate endotracheal intubation. Anaesthesia was maintained with desflurane (2 – 2.2 %) administered in 35% oxygen and 65% N2O with a fresh gas flow of 2 L min-1 and supplemented with additional doses of fentanyl and vecuronium. The patient was placed in the kneeling position; the procedure was uneventful until its final stage. After the disc had been almost completely removed, a sudden drop in SAP/DAP from 110/70 mm Hg to 70/50 mmHg and an increase in HR from 60 min-1 to 120 min-1 were observed.

No significant bleeding was visible in the operating field and end-tidal CO2 remained stable.

Fluid replacement with Ringer’s solution and hydroxyethyl starch 130/0.4 was initiated and 25 mg of ephedrine was administered. During the next ten minutes arterial blood pressure and heart rate stabilized at 120/70 mm Hg and 90 min-1, respectively. At the end of surgery while turning the patient to the supine position, a left-hand palpable abdominal mass was noted. Sedated with the infusion of propofol 50 mg h-1, the patient was transferred for emergency angioCT that revealed a large retroperitoneal haematoma resulting from the injury to the left iliac artery (Fig. 1, 2).

The patient was immediately transferred to the vascular operation theatre. A right internal jugular venous catheter and Foley catheter were placed. Anaesthesia was continued with continuous infusion of propofol 4.8 mg kg-1 h-1 and supplementary doses of fentanyl and vecuronium. The lungs were ventilated with the mixture of oxygen:air (1:1). Urgent laparotomy was performed; a large retroperitoneal haematoma was found and evacuated. A 10-cm tear of the left common iliac artery was identified and repaired.

At the beginning of the vascular procedure, the haemoglobin concentration was 2.1 mmol L-1. During the laparotomy, the patient received 1286 mL of packed red blood cells, 500 mL of fresh-frozen plasma, 1000 mL of Ringer’s solution and 1500 mL of 0.9% NaCl.

During and after the surgery the patient remained haemodynamically stable and the haemoglobin concentration was restored to 5.5 mmol L-1. The patient was discharged from hospital 10 days later after the uneventful postoperative period.

DISCUSSION

This case report describes severe damage to the left common iliac artery during lumbar microdiscectomy, diagnosed on the basis of  cardiovascular instability and the presence of a palpable abdominal mass.

Lumbar disc surgery is a common procedure in neurosurgical departments. The estimated incidence of serious vascular damage, e.g. vascular fistulae, lacerations and pseudoaneurysms during lumbar disc surgery is 1-5 per 10000 [2]. The mortality rate ranges from 25% to 61% depending on the time to diagnosis and length of the subsequent procedure [3]. Surprisingly, the incidence has not been reduced over the past 50 years [4].

Vascular injury most often results from damage caused by instruments such as a pituitary rongeur or forceps [2]. The operative level is closely related to the vessel most commonly damaged. Vascular damage may involve the left and right common iliac artery, the aorta, the inferior vena cava, iliac veins and can lead to the formation of arteriovenous fistulae [5]. Therefore, this kind of injury can manifest itself in various ways, e.g. a fall in blood pressure, an increase in heart rate or decrease in end-tidal CO2 [5, 6, 7]. The intraabdominal injuries observed in the course of lumbar discectomy also include visceral and ureteral trauma [5]. Surgeries at the L4-L5 and L5-S1 levels are predominantly associated with the injuries to the right and left common iliac arteries [2, 5], as in our case.

Many studies have shown that only 60% of patients with major vascular injuries develop bleedings into the operative field [2]. The prone position in which a patient is operated on may confer a degree of vascular compression during surgery, and as such, may temporarily tamponade any vascular tears [1]. Moreover, the small surgical field, especially in microdiscectomy performed with the use of an operating microscope, may hinder the detection of bleeding. It is unclear whether the use of an operative microscope in lumbar discectomy decreases the risk of vascular injury [5].

Early detection of major vascular damage is essential. If vascular damage is suspected, angioCT is a first-line examination to asses the extent of bleeding and to localize it [1, 2]. Moreover, it becomes clear whether active bleeding is still present.

The unexpected occurrence of temporary intraoperative cardiovascular instability should suggest some iatrogenic vascular injury. In the presented case, a palpable abdominal mass was additionally observed. It is a relatively rare finding and can be detectable in a slim patient. The risk factors for such damage include previous disc operations, intraabdominal interventions, or vertebral anomalies [5]. It seems that in our case the aggressive technique of disc removal may have led to the complication.

The previous studies demonstrated that surgical exploration allowed to control bleeding from a traumatized vessel and to evacuate haematoma [2, 5, 6]. There are many techniques of vascular damage repair. Depending on the character of injury, primary suturing, interposition grafting, excision with end-to-end anastomosis, suturing from within the vessel, patch angioplasty and ligation are recommended [5].

Recent advances in endovascular techniques open up new possibilities of less invasive management. In several cases, emergency endovascular coil occlusion of an injured vessel has been successfully applied [1]. In pseudoaneurysms and arteriovenous fistulae, stenting, with or without coil embolization, has also been performed [8, 9].

In conclusion, vascular damage that occurs during lumbar disc surgery should be immediately recognized and treated. The present study indicates that early detection and repair of the injury can result in an excellent outcome.

..............................................................................................................................................................

REFERENCES

1.    Skippage P, Raja J, McFarland R, Belli AM: Endovascular repair of iliac artery injury complicating lumbar disc surgery. Eur Spine J 2008; 17 (Suppl. 2): 228-231.

2.    Papadopoulos S, Konstatinou D, Kourea HP, Kritikos N, Haftouras N, Tsolakis JA: Vascular injury complicating lumbar disc surgery: a systematic review. Eur J Vasc Endovasc Surg 2002; 24: 189-195.

3.    Birkeland IW, Taylor TK: Major vascular injures in lumbar disc surgery. J Bone Joint Surg 1969; 51: 4-19.

4.    Inamusu J, Guiot BH: Vascular injury and complication in neurosurgical spine surgery. Acta Neurochir (Wien) 2006; 148: 375-387.

5.    Erkut B, Ünlü Y, Kaygun MA, Colak A, Erdem AF: Iatrogenic vascular injury during  lumbar disc surgery. Acta Neurochir (Wien) 2007; 149: 511-516.

6.    Sadhasivan S, Kaynar AM: Iatrogenic arteriovenous fistula during lumbar microdiscectomy. Anesth Analg 2004, 99: 1815-1817.

7.    Hönemann CW, Brodner G, Van Ayken H, Ruta U, Duriex ME, Möllhoff T: Aortic perforation during lumbar laminectomy. Anesth Analg 1998, 86: 493-495.

8.    Kwon TW, Sung KB, Cho JP, Kim DK, Ko GY, Yoon HK: Large vessel injury following operation for a herniated lumbar disc. Ann Vasc Surg 2003; 17: 438-444.

9.    Zhou W, Bush RL, Terramani TT, Lin PH, Lumsden AB: Treatment options of iatrogenic pelvic vein injures: conventional operative versus endovascular approach - case reports. Vasc Endovascular Surg 2004; 38: 569-573. 

..............................................................................................................................................................

adres/address:

*Zbigniew Karwacki
Zakład Neuroanestezjologii
Uniwersytetu Medycznego w Gdańsku
ul. Dębinki 7, 80-211 Gdańsk
tel.: 0-58 349 24 06
e-mail: zkarw@gumed.edu.pl

otrzymano/received: 21.06.2009
zaakceptowano/accepted: 19.08.2009