COMPARATIVE STUDY ON THE NEED FOR BLOOD TRANSFUSION IN PATIENTS SUBMITTED TO SPLENECTOMY FOR IMMUNE THROMBOCYTOPENIC PURPURA, WITH AND WITHOUT PREOPERATIVE EMBOLIZATION OF THE SPLENIC ARTERY

ESTUDO COMPARATIVO DA NECESSIDADE DE TRANSFUSÕES SANGUINEAS EM PACIENTES SUBMETIDOS A ESPLENECTOMIA POR PÚRPURA TROMBOCITOPÊNICA IMUNE COM E SEM EMBOLIZAÇÃO PRÉ-OPERATÓRIA DA ARTÉRIA ESPLÊNICA.

Baú,PlínioCarlos¹ ..Cavazolla,Sílvio Adriano². Souza,Hamilton Petry³ Garicochea, Bernardo⁴

1 Associate Professor, MD, PhD, at the Surgery Division of the Faculdade de Medicina PUCRS

2 Interventionist Radiologist at the Hospital São Lucas PUCRS

3 Associate Professor, PhD, Surgery Division of the Faculdade de Medicina PUCRS

4 Associate Professor, PhD, Oncology Division of the Faculdade de Medicina PUCRS

Abstract

Platelet and/or red blood cell transfusion is usually necessary immediately after the splenic artery ligature in patients with Immune Thrombocytopenic Purpura who are submitted to splenectomy .The purpose of this study is to test whether preoperative embolization of the splenic artery can reduce the need for transfusion of platelets and/or red blood cells. Twenty- seven consecutive patients submitted to splenectomy for purpura between October 1999 and March 2006 by the same surgical team were enrolled. The first 17 patients were not submitted to embolization and were compared to the next 10 patients in whom embolization was performed. The platelet count in the embolization group rose from an average of 7000 u/µl before the procedure to 75000 u/µl afterwards. There was no need for platelet and red blood cell transfusion in the group submitted to embolization compared to 11 patients (p=0.001) with platelet transfusion and 8 patients (p=0.01) with red blood cell transfusion in the group without preoperative embolization. We concluded that embolization of the splenic artery pre-splenectomy is a safe method to avoid blood transfusion in ITP patients.

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 se a embolização pré-operatória da artéria esplênica é eficaz na redução da necessidade de transfusão de hemácias ou plaquetas. Vinte e sete 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 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. Não foi necessário transfundir plaquetas ou glóbulos vermelhos no grupo submetido a embolização comparado com 11 pacientes com transfusão de plaquetas (p=0,001) e 8 pacientes com transfusão de hemácias (p=0,01) no grupo sem embolização pré-operatória .Concluímos, neste estudo, que a embolização pré-operatória da artéria esplênica é um método seguro e eficaz para evitar o uso de transfusões em esplenectomias por PTI.

Introduction

The principal complication of splenectomy is the significant blood loss associated to the procedure, due to the peculiar blood supply and parenchymal fragility of the organ. Experiments with preoperative splenic artery embolization (PAE) reported in the early ´90s suggested that this approach could reduce the risk of hemorrhage ^1,2.The effect of PAE on blood loss seems to be independent of the surgical technique used or whether the procedure is performed by laparoscopy or laparotomy³ PAE looks especially promising in cases of Immune Thrombocytopenic Purpura (ITP) since many of these patients have their splenectomy indicated while presenting very low platelet levels. The use of PAE before the splenectomy for ITP patients could even diminish the need for pre and transoperative platelet transfusions which are the standard practice for these cases⁴. We decided to verify if the use of PAE before splenectomy is associated to a reduced need of platelet and red blood units transfused in a series of ITP patients compared to a historical group that was treated with splenectomy without PAE.

Patients and methods

A controlled historical study was performed involving patients submitted to splenectomy for Immune Thrombocytopenic Purpura between October 1999 and March 2006 at São Lucas Hospital, PUCRS (Pontificia Universidade Católica do Rio Grande do Sul). The experimental group involved 10 patients with PAE submitted to splenectomy, with mean age of 29 years (range 16 to 78) while the control group consisted in 17 individuals splenectomized without PAE. The demographics characteristics of two groups are displayed in table 1. Six patients of the experimental group (60%) and 13 of the control group (76%)were submitted to laparoscopic splenectomy .The remaining, to laparotomic splenectomy.

PAE was performed 6 to 12 hours before surgery. The technique⁵consisted in a puncture of the femoral artery with catheterization of the splenic artery by fluoroscopy and infusion of a vial of PVA micro particles with a 300-355-m diameter (Contour Emboli, Boston Scientific Cork Ltd Ireland) added to 30 ml of iodinated contrast. The amount of PVA particles used in the procedure varied according to the spleen volume. The procedure was considered satisfactory whenever 60 –70% of the parenchyma volume was embolized. The option for laparoscopic or laparotomic technique was based on the spleen volume. Laparotomy was chosen for cases in which the spleen was larger than1000ml, as evaluated by ultrasound.

The criteria used to define the need for preoperative transfusion of blood and blood products were based on the practical guidelines of the American Society of Anesthesiologists⁶ Red blood cells were transfused when the hemoglobin levels were under 6 g/dl. At levels between 6 and 10 g/dl transfusion was indicated only in case of bleeding or when the patients were at risk of complications due to inadequate oxygen supply (low cardiopulmonary reserve or high oxygen consumption). Platelet transfusion was indicated when the levels were under 50 X 10⁹/l and/or bleeding occurred.

Initially, the two groups were compared concerning the baseline clinical and laboratory aspects that might determine a different outcome during the postoperative period. The Student t test was used to compare quantitative data, which followed the Normal distribution. In case of asymmetry, we used the non-parametric Mann-Whitney test. The categorical variables were compared using the chi-square tests and the Fisher exact test (due to the small sample). The level of significance adopted was (a=0,05) and data were analyzed using program SPSS version 12.0.

Results

The clinical data and the transfusion needs for the study and control group are shown in table 1. The two groups had similar demographic variables. Regardless of the splenectomy technique used, no difference was found between laparoscopy or laparotomy, and the need for transfusion (p=0.17). The embolized group did not receive any red blood cell or platelet transfusion, while in the non-embolized group, 8 patients received packed red blood cells (p=0.01) and 11 patients received platelets (p=0.001) (graph 1). The transfused group received a mean of 3.2 U of red blood cells and 9.2 U of platelets. The platelets levels increased significantly in the group submitted to preoperative embolization (figure 1). No deaths were observed in either group.

Table 1 – Characteristics of patients in the study on splenectomy for Immune Thrombocytopenic Purpura (ITP) submitted or not to preoperative embolization of the splenic artery.

	Study group (PAE)	Control group (no PAE)
Characteristics	n = 10	n = 17	P
Age, years	29 (16 to78)	32 (11 to 52)	0.71
Female, nº (%)	4 (40)	12 (71)	0.22
Platelets (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 postoperative	133 (109 to 345)	125 (19 to 477)	0.29
7th day postoperatively	345 (151 to 500)	215 (120 to 673)	0.26
Surgical technique, nº (%)			0.17
Laparotomy	4 (40)	4 (24)
Laparoscopy	6 (60)	13 (76)
Need for transfusion, nº (%)
RBCU	0 (0)	8 (47)	0.01
Platelets	0 (0)	11 (65)	0.001

The data are presented as median (minimum to maximum) or nr. (percentage).

RBCU: packed adult red blood cells.

Graph 1: Platelet count for the period

Discussion

Mortality and morbidity associated to splenectomy are declining in the last two decades in part due to technical advances in the surgical procedure. Among these technical advances, the video-laparoscopic approach and the embolization of the splenic artery can be mentioned as some of the most relevant developments. Even with the help of these new weapons, splenectomy is still regarded as a risk procedure, especially because the clinical conditions which lead to it are generally critical. The technical evolution in the surgical procedure of splenectomy was well established in a comprehensive metanalysis performed with almost 3000 patients in which general complications seen in open splenectomy were significantly higher than with laparoscopic splenectomy (26% vs 16%)³. Despite this stimulating result, when the hemorrhagic complications were analyzed separately, the authors concluded that there was no difference between the two surgical procedures. Small series of patients from the past in which ITP patients were splenectomized by LS or with the use of PAE yielded confusing results^{1,2 .} Conversion of LS to OS was reported in a considerable number of patients in one study ²,despite the use of PAE, arising the question if these procedures (PAE and LS) should not be reserved exclusively for a subgroup of individuals with smaller spleens and better clinical conditions.

In the present report, all individuals studied required splenectomy due to clinical refractory ITP. All of them, as expected, displayed spleens with normal or slightly elevated volume. In the group in which PAE was not performed, the hemorrhagic complications were severe enough to require platelet transfusions in 65% and red blood cells in 47% of cases. In the group submitted to PAE, blood transfusion was not required. As soon as the technique was available in our institution, by mid 1999, PAE was offered to almost all patients, so there was no selection of individuals based on clinical performance or platelet number count. These interesting results are even more compelling if we consider that the patients studied were thrombocytopenic. It is important to emphasize that previous studies with PAE enrolled splenectomized patients with hematological and non-hematological disorders, moreover, when the procedure is evaluated, PAE seemed to be the most important factor to determine the absence of transfusion, because both OS as LS patients were favored by the procedure avoiding blood products.

Conclusion

The results seem to confirm that the preoperative embolization of the splenic artery in splenectomy for ITP offers the same of advantages when compared with individuals without embolization. The embolization technique is safety and may be reproduced without morbidity, because of the advances in the radiological procedures. The use of PAE it seems to be a great advance on surgical treatment of ITP, preventing the needs of blood transfusion despite the surgical technique used.

References

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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:

Plínio Carlos Baú

Av Ipiranga,6690/506

90610-000 Porto Alegre-RS

pliniobau@via-rs.net