Successful Revascularization with Intraoperative Venous Drainage of Ischemic Limbs Through Hemodialysis in Severe Acute Saddle Aortic Embolism
Article Outline
Abstract
We report a successful treatment in a patient with acute saddle aortic embolism by the intraoperative venous drainage of severely ischemic lower limbs through hemodialysis during the surgical embolectomy. The procedure provided the stability of hemodynamic status, the effective equilibration of metabolic disturbance and the minimal organ dysfunction in the management of this lethal problem.
Keywords: Aortic embolism, Acute limb ischemia, Intraoperative venous drainage, Intraoperative hemodialysis, Reperfusion injury
Revascularization of acute aortic embolism with immediately threatened ischemia is associated with high rates of morbidity and mortality related to massive reperfusion of toxic metabolic products.1Washing out venous blood of the ischemic limb during the process of revascularization may prevent the reperfusion injury in the animal model.2 We firstly reported a successful treatment in a patient with acute saddle aortic embolism and severely ischemic lower limbs by the intraoperative drainage of venous blood through hemodialysis during the surgical embolectomy.
2. Case report
A 60-year-old lady presented with the first episode of suddenly severe pain on both legs for 22 h prior to the referral to our vascular surgery unit. The significant physical findings were cold, mottled and cyanotic skin of her both legs and the complete paralysis of leg muscles together with the absence of bilateral femoral pulses. The electrocardiography demonstrated atrial fibrillation with rapid ventricular rate. The persistent hyperkalemia (serum potassium = 7.0 mmol/L) and severe acidosis (pH = 7.1 and serum bicarbonate = 13 mmol/L) could not be corrected by multiple infusions of calcium gluconate, sodium bicarbonate and glucose with insulin. In the emergency room, she was intubated and underwent respiratory support due to severe hypoxia. Five thousand units of unfractionated heparin were intravenously injected at this stage.
She was immediately transferred to the operating theatre with arterial pressure stabilized by inotropic agents. After the patient being anesthetized and undergoing double lumen catheterization into the right internal jugular vein, hemodialysis was taken place to improve the metabolic state. Femoral arteries and veins were isolated bilaterally through the groin incisions. Surgical embolectomies were immediately performed, obtaining extensive blood clot from proximal and distal arteries of the ischemic limbs. After the closure of arteriotomies, vascular clamps were still left on those arteries. For the set up of the venous drainage system of the ischemic limbs, bilateral common femoral veins were cannulated distally with the No. 22Fr venous cannulae (Medtronic) which were further connected to a Y-shaped tube and a standard hemodialysis tube respectively. These tubes were finally connected to the hemodialysis system and the double lumen catheter (Fig. 1). As soon as the revascularization commenced with releasing the vascular clamps from the femoral arteries, the drainage of venous outflow blood containing anaerobic metabolic substances from the ischemic limbs was established through common femoral veins and hemodialysis system with flow rate 300 mL/min. Low-flux dialyser with the surface area of 1.9 square meters (SF 190E, Nipro) and dialysate containing sodium 140 mmol/L, potassium 2 mmol/L, calcium 1.5 mmol/L and bicarbonate 35 mmol/L were used in the hemodialysis system. The dialysed blood was reinfused into the patient through the double lumen catheter.
Figure 1
The intraoperative venous drainage system of the severely ischemic limbs through hemodialysis during the surgical embolectomies in this patient with acute saddle aortic embolism.
During the process of revascularization, the hemodynamic status was stable except for the persistent tachycardia and atrial fibrillation. Intractable hyperkalemia and severe acidosis in the systemic circulation prior to surgery were partially and temporarily corrected by the initial hemodialysis. However, extremely high serum potassium (8.4 mmol/L) and severe acidosis (pH = 7.0) persisted in the venous circulation of the ischemic limbs for 45 and 120 min respectively while those in the systemic circulation were within normal range during the intraoperative venous drainage (Fig. 2). The hemodialysis was discontinued after the system had run for 150 min with the stabilized metabolic disturbance. The fasciotomies were performed on both legs due to the compartment syndrome after revascularization.
Figure 2
The level of serum potassium (A) and pH (B) in systemic circulation and venous outflow blood of ischemic limbs before, during and after the surgical embolectomies.
In the intensive care unit, the arterial pressure remained stable with small doses of inotropic agents. These medications were tapered off and respiratory support was discontinued on the postoperative day 1. The patient was oliguric requiring continuous renal replacement therapy for 3 days and another hemodialysis on day 5 after the revascularization. Following these treatments, urine output was normal with optimal renal function. Anticoagulants and antibiotics were administered as the routine regimen of the treatment of the peripheral arterial embolism. Postoperatively, peripheral ankle pulses were palpable on both legs. However, the compartment syndrome further detected on the left thigh was treated by the fasciotomies on postoperative day 1. Muscle power of the lower extremities was gradually improved. She has been walking at sixth month and remains well with twelve month follow-up period.
3. Discussion
The subsequent ischemic process in acute saddle aortic embolism becomes rapidly and progressively worse due to the massive accumulation of the anaerobic metabolites, released into the circulation. The extremely high level of potassium, acid metabolites and oxygen derived free radicals from the ischemic tissue can damage vital organs and interrupt their functions resulting in the disturbance of hemodynamic status and multiorgan failure.3 Revascularization of this disease with immediately threatened ischemia rapidly introduces the perfusion of these substances into the systemic circulation.4 Particularly in this patient, the clinical status was critical with impending limb gangrene and severe metabolic disturbance. Due to the absence of muscle rigidity, limb preservation was still attempted. However, severe cardiac arrhythmia and sudden cardiovascular collapses were expected immediately after revascularization.5Intraoperative venous drainage of the ischemic limb into the hemodialysis system could effectively divert blood containing these toxic substances from the ischemic tissue. The effectiveness was demonstrated through the stability of vital signs and electrocardiography during the release of vascular clamps and the ongoing process of revascularization. Hemodialysis in this system could adequately equilibrate the level of potassium and acid-base balance from venous blood of distal ischemic limbs before entering into the systemic circulation. This was confirmed by the significantly different level of potassium and pH in the venous outflow blood of the ischemic limbs compared with those optimized normally in the systemic circulation (Fig. 2 A and B). Furthermore, only temporary and minimal deterioration of renal function also supported the efficiency of this procedure. With the extremely high level of potassium and low pH level in venous blood of distal ischemic limbs, intraoperative systemic hemodialysis without the drainage of venous outflow from the ischemic limbs may not be able to effectively prevent reperfusion injury during the process of revascularization in this patient.6 The persistency of severe hyperkalemia and acidosis in venous blood of the lower extremities for 45 and 120 min respectively during the intraoperative venous drainage also supported this opinion. The requirement of thigh and calf fasciotomies for the compartment syndrome in those areas confirmed the extensive ischemic process in the lower extremities. The strategy of this procedure to prevent reperfusion injury through venous system was different from that of controlled limb reperfusion approaching the problem through arterial system.7, 8 The latter modality provided the optimal temperature and pressure of arterial inflow during the revascularization and the appropriate composition of reperfusate for the intraarterial infusion into ischemic limb.9 The comparison of the effectiveness between the two modalities using different strategies may require the information from the study in experimental models. Compared with the technique of extracorporeal circulation of the lower extremities using heart–lung machine, membrane oxygenator and hemofiltration process,10 this treatment was comparably effective but more simple and cheaper.
In conclusion, intraoperative venous drainage of ischemic limbs through hemodialysis may be the effective adjunct procedure of surgical embolectomies to provide the successful treatment of severe acute saddle aortic embolism.
Conflict of Interest/Funding
None.
Acknowledgments
The authors deeply appreciate the advice of Associate Professor P. Vessakosol(Ph.D) and Miss S. Tunpornpituk in the preparation of this manuscript.
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PII: S1533-3167(09)00031-4
doi:10.1016/j.ejvsextra.2009.09.003
Crown Copyright © 2009. Published by Elsevier Inc. All rights reserved.
Refers to article:
- Successful Revascularization with Intraoperative Venous Drainage of Ischemic Limbs Through Hemodialysis in Severe Acute Saddle Aortic Embolism , 30 October 2009
