ESTUDO COMPARATIVO DA NECESSIDADE DE TRANSFUSÃO SANGÜÍNEA EM PACIENTES SUBMETIDOS A ESPLENECTOMIA POR PÚRPURA TROMBOCITOPÊNICA IDIOPÁTICA, COM E SEM EMBOLIZAÇÃO PRÉ-OPERATÓRIA DA ARTÉRIA ESPLÊNICA

PREOPERATI= VE EMBOLIZATION OF THE SPLENIC ARTERY IN PATIENTS THAT UNDERWENT SPLENECTOMY F= OR IMMUNE THROMBOCYTOPENIC PURPURA

Baú, PlínioCarlos¹.Cavazolla, Sílvio Adriano². Souza, Hami= lton Petry³ Garicochea, Bernardo⁴

1 Associate Professor, MD, PhD, Surgery Division, Schoo= l of Medicine, Pontifícia Universidade Católica do Rio Grande do S= ul (PUCRS), Porto Alegre, Brazil.

Abstract

Transfusion of platelets, red blood cells, or both is usually necessary immediately after splenic artery ligature in patients with immune thrombocytopenic purpura who undergo splenectomy. The purpose of this study was to investigate whether preoperat= ive embolization of the splenic artery reduced the need for transfusion of platelets, red blood cells, or both. Twenty- seven consecutive patients that underwent splenectomy for purpura between October 1999 and March 2006 perfo= rmed by the same surgical team were enrolled. The first 17 patients did not unde= rgo embolization and were compared with the next 10 patients, who composed the embolization group. The platelet count in the embolization group rose from a mean 7000 u/µl before to 75000 u/µl after the procedure. There = was no need for platelet or red blood cell transfusion in the embolization grou= p; in the group without preoperative embolization, 11 patients (p=3D0.001) req= uired platelet transfusion and 8 (p=3D0.01), red blood cell transfusion. Embolization of t= he splenic artery before splenectomy is a safe method to avoid blood transfusi= ons in patients with ITP.

Resumo

A transfusão de plaquetas e/ ou hemácias geralmente é realizada em pacientes submetidos a esplenectomia por Purpura Trombocitopênia Imune (PTI). O objetivo deste estudo é testar<= span style=3D'mso-spacerun:yes'> se a embolização pré-operatória da artéria esplênica é eficaz na redução da necessidade de transfusão de hemácias ou plaquetas. Vinte e s= ete pacientes foram submetidos a esplenectomia por PTI de Outubro de 1999 a Março de 2006 pela mesma equipe cirúrgica. Os primeiros 17 pacientes não foram submetidos a embolização e foram comparados com os outros 10 individuos&nbs= p; nos quais a embolização foi realizada. A contagem de plaquetas no grupo em que a embolização foi realizada subiu de uma média de 7000u/µl antes do procedimento, para 75000 u/µl após. N&at= ilde;o foi necessário transfundir plaquetas ou glóbulos vermelhos no grupo submetido a embolização comparado com 11 pacientes com transfusão de plaquetas (p=3D0,001) e 8 pacientes com transfus&atild= e;o de hemácias (p=3D0,01) no grupo sem embolização pré-operatória .Concluímos, neste estudo, que a emboli= zação pré-operatória da artéria esplênica é um método seguro e eficaz para evitar o uso de transfusões em esplenectomias por PTI.

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Introduction<= /o:p>

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The major complication of splenectomy is significant blood loss, whi= ch is explained by the peculiar blood supply and parenchymal fragility of the = spleen. Studies of preoperative splenic artery embolization (PAE) in the early 1990s suggested that this procedure might reduce the risk of hemorrhage [1,2]. The effect of PAE on blood loss seems to be independent of the surgical techniq= ue used or of whether the procedure is performed by laparoscopy or laparotomy = [3]. PAE seems especially promising for patients with immune thrombocytopenic purpura (ITP) because many have low platelet counts at the time when splenectomy is indicated. The use of PAE before splenectomy for patients wi= th ITP may reduce the need for pre- and transoperative platelet transfusions, which still are standard practices [4]. We investigated whether the use of = PAE before splenectomy was associated with a reduced need of platelet or red bl= ood transfusion in a series of patients with ITP compared with a historical gro= up of patients that underwent splenectomy without PAE.

Patients and metho= ds

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This controlled study enrolled a historical cohort of patients that underwent splenectomy for immune thrombocytopenic purpura between October 1999 and Ma= rch 2006 in our institution.. The study group comprised 10 patients that underw= ent preoperative splenic artery embolization (PAE) and whose mean age was 29 ye= ars (range 16 to 78). The control group consisted of a historical series of 17 patients that underwent splenectomy without PAE. The demographic characteristics of the two groups are shown in Table 1. Splenectomy was performed using laparoscopy in 6 patients of the study group (60%) and 13 of the control group (76%), and using laparotomy in the other patients of both groups. This study was approved b= y the Committee on Research Ethics of the hospital where it was conducted. Written informed consent was obtained from all participants.

Embolization technique

PAE was performed 6 to 12 hours before surgery. The technique [5]co= nsisted of puncture of the femoral artery with catheterization of the splenic arter= y by fluoroscopy and infusion of a vial of PVA particles 300-355 = m in diameter (Contour Emboli, Boston Scientific Cork Ltd, Irel= and) added to 30 ml of iodinated contrast. The quantity of PVA particles used in= the procedure varied according to spleen volume. The procedure was classified as satisfactory whenever 60–70% of the parenchyma volume was embolized. = The choice of laparoscopy or laparotomy was made according to spleen volume: laparotomy was used for spleens larger than 1000 ml, as evaluated by ultrasound.

The need of preoperative transfusion of blood and blood products was defined according = to the practical guidelines of the American Society of Anesthesiologists [6]. = Red blood cells were transfused when hemoglobin level was below 6 g/dl. At leve= ls between 6 and 10 g/dl, transfusion was indicated only in case of bleeding or when the patient was at risk of complications due to inadequate oxygen supp= ly (low cardiopulmonary reserve or high oxygen consumption). Platelet transfus= ion was indicated when platelet count was below 50 X 10⁹/L or when bleeding occurred.

Baseline clinical and laboratory data = that might determine different postoperative outcomes were compared between the = two groups. The Student t test was used to compare quantitative, normally distributed data. In case of asymmetry, the non-parametric Mann-Whitney test was used. Categorical variables were compared using chi-square and the Fish= er exact tests because of the small sample size. The level of significance was= set at a<= /span>=3D0.05, and data were analyzed u= sing the SPSS 12.0 software.

Results

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= Clinical data and transfusion needs of the study and control groups = are shown in Table 1. Demographic variables were similar in the two groups. No differences were found between laparoscopy or laparotomy and the need of transfusion (p=3D0.17). The embolization group did not receive any red bloo= d cell or platelet transfusions; in the group without PAE, 8 patients received pac= ked red blood cells (p=3D0.01) and 11, platelets (p=3D0.001) (graph 1). Patient= s that needed transfusion received a mean 3.2 U red blood cells and a mean 9.2 U platelets. Platelet counts increased significantly in the embolization group (figure 1). No deaths were observed in either group.

Discussion

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The rates of mortality and morbidity associated with splenectomy have declined = in the last two decades partly because of technical advances in surgical procedures. Videolaparoscopy and embolization of the splenic artery are two= of the most relevant developments in this area. However, splenectomy is still regarded as a risk procedure, especially because of the usually critical clinical conditions that lead to it. The technical evolution of splenectomy= was well established in a comprehensive metanalysis with almost 3000 patients, = in which a significantly greater number of general complications was found in = the open splenectomy (OS) group than in laparoscopic splenectomy (LS) group (26% vs. 16%) [3]. Despite such encouraging results, the separate analysis of hemorrhagic complications showed that there were no differences between the= two surgical procedures. Studies with small series of patients with ITP who underwent splenectomy using LS or who received PAE reported conflicting res= ults [1,2].Several patients required conversion from LS to OS in one study [2] despite the use of PAE, which raises the question of whether PAE = and LS should be reserved exclusively for a subgroup of patients with smaller spleens and better clinical conditions.

Blood transfusions carry t= he risk of triggering immune responses, particularly due to immunosuppression = and proinflammatory effects, which may lead to acute lung injury, as well as the risk of infections, such as HIV, hepatitis and syphilis.<= /span>

= In this study, all patients underwent splenectomy because of clinica= lly refractory ITP, and all had, as expected, normal-sized or slightly enlarged spleens. In the group in which PAE was not performed, hemorrhagic complicat= ions were severe enough to require transfusions of platelets in 65% and of red b= lood cells in 47% of the cases. In the group that underwent PAE, blood transfusi= ons were not necessary.

The PAE technique has been offered to almost all o= ur patients since it became available in our institution in 1999. In this stud= y, there was no selection of patients according to clinical data or platelet counts, and our results are even more compelling because the study patients= had thrombocytopenia. Previous PAE studies enrolled splenectomized patients with hematological and non-hematological disorders, and reported that PAE seemed= to be the most important factor in avoiding transfusion. Moreover= , PAE, which precludes the use of blood products, was beneficial to both OS and LS patients.

Our review of the literature did not yield any studies with a sample of patient= s as large as the one in our series. Our study compared study and control groups= in an attempt to reach a definitive conclusion about the advantages of PAE. The studies published so far, such as the one conducted by Poulin et al. [2], enrolled patients that underwent splenectomy due to several pathologies, and not due to a specific disease such as ITP. Other studies were case reports = of selected patients (4) .

&nb= sp; One of = the limitations of our study was the relatively small number of patients in the study group, as ITP is a rare pathology usually treated clinically in our institution. This also explains why a historical series was used to compose= the control group.

Conclusion

Our results seem to confirm the advantages of preoperative embolization of the splenic artery for patients that undergo s= plenectomy for ITP when compared with patients without PAE.

This embolization technique is safe and not associated with postoperative morbid= ity because of advances in radiological procedures. The use of PAE seems to be a great advance in the surgical treatment of ITP as it prevents blood transfusions regardless of which surgical technique is used.

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References

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1. Totte E, Van Hee R, Kloec= k I, Hendrickx L, Zachee P, Bracke P, Hermans P. Laparoscopic splenectomy after arterial embolization. Hepato-Gastroenterology 1998;45:773-776

2. Poulin E, Thibault C, Mam= azza J, Girotti M, Côté G, Renaud A. Laparoscopic splenectomy: clin= ical experience of preoperative splenic artery embolization. Surgical Laparoscopy & Endoscopy 1993;3(6):445-450

3. Winslow ER, Brunt MB. Per= ioperative outcomes of laparoscopic versus open splenectomy: A meta-analysis with an emphasis on complications. Surgery 2003;134(4):647-655.

4. Bahini, A, Hannoun, L, Pa= rc, R. Embolisation Pré-Opératoire de L’Artère Splénique. Annales de Chirurgie,1986; V 40 –3, 201-204<= /p>

5. Spigos CL, Boxt LM, Bettm= an MA. Partial splenic embolization in treatment of hypersplenism. AJR Am J Roentegenol 1979; 132: 777-782.

6. Practice guidelines for perioperative blood transfusion and adjuvant therapies. Anesthesiology 2006;105:198-208

7. Cordera F, Long = KH, Nagorney DM, McMurtry EK, Schleck C, Ilstrup D, Donohue JH. Open versus laparoscopic splenectomy for idiopathic thrombocytopenic purpura: clinical = and economic analysis. Surgery 2003;134(1):45-52.

Correspondence: = &nb= sp; = &nb= sp; = &nb= sp; =

Plínio Carlos Baú

Av Ipiranga,6690/506

90610-000 Porto Alegre, RS, Brazil

pliniobau@via-rs.net

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Table 1 – Characteristics of patients that underwent splenectomy for immune thrombocytopenic purpura (ITP) with or without preoperative embolization of the splenic artery (PAE).

	Study group (PAE)=	Control group (no= PAE)	=
Characteristics	n =3D 10	n =3D 17	P
Age, y= ears	29 (16 to78)	32 (11 to 52)	0.71
	=	=	=
Female= , N (%)	4 (40)	12 (71)	0.22
	=	=	=
Platel= ets (U/ μl) x 1000	=	=	=
Baseline	6 (4 to 17)	6 (1 to 20)	0.99
Surgery	75 (9 to 231)	6 (1 to 20)	<0.001
Immediately after operation	133 (109 to 345)	125 (19 to 477)	0.29
7th postoperative day	345 (151 to 500)	215 (120 to 673)	0.26
	=	=	=
Surgic= al technique, N (%)	=	=	0.17
Laparotomy	4 (40)	4 (24)	=
Laparoscopy	6 (60)	13 (76)	=
	=	=	=
Need of transfusion, N (%)	=	=	=
RBCU	0 (0)	8 (47)	0.01
Platelets	0 (0)	11 (65)	0.001

Data are described as median (minimum to maximum) or frequency (percentage).

RBCU: packed adult red blood cells.

Gra= ph 1: Platelet counts

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