Antibody response to a T-cell-independent antigen is preserved after splenic artery embolization for trauma

Optimizing distal and proximal splenic artery embolization with patient-specific computational fluid dynamics

Splenic artery embolization (SAE) has become a favored alternative to splenectomy, offering a less invasive intervention for injured spleens while preserving spleen function. However, our understanding of the role that hemodynamics plays during embolization remains limited. In this study, we utilized patient-specific computational fluid dynamics (CFD) simulations to study distal and proximal embolization strategies commonly used in SAE. Detailed 3D computer models were constructed considering the descending aorta, various major visceral arteries, and the iliac arteries. Subsequently, the blood flow and pressure associated with different coil placement locations in proximal embolization were studied considering the collateral vessels. Coil induced variations in pressure fields were quantified and compared to baseline. The coil induced flow stagnation was also quantified with particle residence time. Distal embolization was modeled with Lagrangian particle tracking and the effect of particle size, release location, and timing on embolization outcome was studied. Our findings highlight the crucial role of collateral vessels in maintaining blood supply to the spleen following proximal embolization. It was demonstrated that coil location can affect distal pressure and that strategic coil placement guided by patient-specific CFD simulations can further reduce this pressure as desired. Additionally, the results point to the critical roles that particle size, release timing, and location play in distal embolization. Our study provides an early attempt to use patient-specific computer modeling for optimizing embolization strategies and ultimately improving patient outcomes during SAE procedures.

Standardizing quality utilization of interventional radiology treatments of blunt splenic injury: SQUIRTS study

OBJECTIVES

Nonoperative management (NOM) of blunt splenic injury (BSI) is well accepted in appropriate patients. Splenic artery embolization (SAE) in higher-grade injuries likely plays an important role in increasing the success of NOM. We previously implemented a protocol requiring referral of all BSI grades III-V undergoing NOM for SAE. It is unknown the risk of complications as well as longitudinal outcomes. We aimed to examine the splenic salvage rate and safety profile of the protocol. We hypothesized the splenic salvage rate would be high and complications would be low.

METHODS

A retrospective study was performed at our Level 1 trauma center over a 9-year period. Injury characteristics and outcomes in patients sustaining BSI grades III-V were collected. Outcomes were compared for NOM on protocol (SAE) and off protocol (no angiography or angiography but no embolization). Complications for angiographies were examined.

RESULTS

Between January 2010 and February 2019, 570 patients had grade III-V BSI. NOM was attempted in 359 (63 %) with overall salvage rate of 91 % (328). Of these, 305 were on protocol while 54 were off protocol (41 no angiography and 13 angiography but no SAE). During the study period, for every grade of injury a pattern was seen of a higher salvage rate in the on-protocol group when compared to the off-protocol group (Grade III, 97 %(181/187) vs. 89 %(32/36), Grade IV, 91 %(98/108) vs. 69 %(9/13) and Grade V, 80 %(8/10 vs. 0 %(0/5). The overall salvage rate was 94 %(287) on protocol vs. 76 %(41) off protocol (p < 0.001, Cochran-Mantel-Haenszel test). Complications occurred in only 8 of the 318 who underwent angiography (2 %). These included 5 access complications and 3 abscesses.

CONCLUSION

The use of a protocol requiring routine splenic artery embolization for all high-grade spleen injuries slated for non-operative management is safe with a very low complication rate. NOM with splenic angioembolization failure rate is improved as compared to non-SAE patients' at all higher grades of injury. Thus, SAE for all hemodynamically stable patients of all high-grade types should be considered as a primary form of therapy for such injuries.

Non-operative management of high-grade splenic injury: a systematic review protocol

OBJECTIVE

The objective of this review is to establish whether embolization is more effective than clinical observation for adult patients with grade III-V splenic injuries. The findings will be used to guide future practice and, if necessary, inform future research design and conduct.

INTRODUCTION

The spleen is one of the most frequently injured intra-abdominal organs, with a reported adult mortality of 7% to 18% following trauma. Non-operative management has become a standard of care for hemodynamically stable patients. In clinical practice, the decision whether to prophylactically embolize or manage high-grade injuries with observation alone remains controversial.

INCLUSION CRITERIA

Sources including adult patients with grade III-V splenic injuries secondary to blunt trauma will be included in this review. Eligible studies must include comparisons between 2 cohorts of patients undergoing either prophylactic embolization or clinical observation only. Outcomes will include mortality rate, failure of treatment, intensive care unit admission, length of hospital stay, blood transfusion requirements, and patient satisfaction.

METHODS

A systematic review with meta-analysis will be conducted. PubMed, Embase, and CINAHL will be searched for eligible studies, as will trial registries and sources of gray literature. Study selection, quality appraisal, and data extraction of outcomes will be performed in duplicate. Methodological quality will be evaluated using JBI critical appraisal tools. Studies will, where possible, be pooled in statistical meta-analysis. A random effects model will be used and statistical analysis will be performed. The certainty of the findings will be assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

REVIEW REGISTRATION

PROSPERO CRD42023420220.

Long-Term Effects of Proximal Splenic Artery Embolization on Splenic Volume and Platelet Count

BACKGROUND

The spleen is the most commonly injured visceral organ in blunt abdominal trauma. Post-splenectomy infection risk has led to the shift toward spleen preserving procedures and splenic artery embolization (SAE) is now the treatment of choice for hemodynamically stable patients with splenic injury. This study aims to assess the long-term effect of SAE on splenic volume and platelet count.

MATERIALS AND METHODS

Using CPT codes, 66 patients who underwent SAE were identified, and 14 of those who had the necessary imaging and laboratory follow-up were included in the study. Indications for SAE were portal hypertension in 8 patients, bleeding in 4 patients, and thrombocytopenia in 1, and one patient had a separate indication. Splenic volume was calculated by automated volumetric software (Aquarius, TeraRecon, Inc.). Paired t-tests were performed to compare splenic volume and platelets before and after SAE.

RESULTS

Fourteen patients (7 males, 7 females) with a mean age of 51 ± 11.95 years underwent SAE and were followed by a repeat computed tomography scan at an average of 733.57 days. Nine SAEs were performed using vascular plugs, 3 using micro coils, and 2 out of that were with Gelfoam slurry, and 2 using coils only. All embolizations were technically successful with complete cessation of flow. Mean splenic volumes pre- and post-SAE were 903.5 ± 523.73 cm³ and 746.5 ± 511.95 cm³, respectively, representing a mean decrease of 8.31% compared to baseline [P = 0.346]. Minimum platelet counts (x10³) pre-SAE (within 3 months) and post-SAE (2 weeks to 3 months after the procedure) were 55.79 ± 57.11 and 116 ± 145.40, respectively. The minimum platelet count showed a statistically significant mean increase of 134.92% (P = 0.033).

CONCLUSIONS

The splenic volume is not altered significantly by SAE in the long term. Similarly, the platelet count is also not significantly altered at 3 months follow-up. This study, although small, suggests that SAE is a safe intervention that can preserve splenic volume and function in the long term.

Vaccination after spleen embolization: A practice management guideline from the Eastern Association for the Surgery of Trauma

BACKGROUND

Angioembolization is an important adjunct in the non-operative management of adult trauma patients with splenic injury. Multiple studies have shown that angioembolization may increase the non-operative splenic salvage rate for patients with high-grade splenic injuries. We performed a systematic review and developed evidence-based recommendations regarding the need for post-splenectomy vaccinations after splenic embolization in trauma patients.

METHODS

A systematic review and meta-analysis of currently available evidence were performed utilizing the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

RESULTS

Nine studies were identified and analyzed. A total of 240 embolization patients were compared to 443 control patients who neither underwent splenectomy nor were embolized. There was no statistical difference between the splenic immune function of embolized and control patients. In addition, a total of 3974 splenectomy patients was compared with 686 embolization patients. Embolization patients had fewer infectious complications and a greater degree of preserved splenic immune function.

CONCLUSION

In adult trauma patients who have undergone splenic angioembolization, we conditionally recommend against routine post-splenectomy vaccinations.

STUDY TYPE

systematic review/meta-analysis Level of evidence: level III.

Follow-up strategies for patients with splenic trauma managed non-operatively: the 2022 World Society of Emergency Surgery consensus document

Background

In 2017, the World Society of Emergency Surgery published its guidelines for the management of adult and pediatric patients with splenic trauma. Several issues regarding the follow-up of patients with splenic injuries treated with NOM remained unsolved.

Methods

Using a modified Delphi method, we sought to explore ongoing areas of controversy in the NOM of splenic trauma and reach a consensus among a group of 48 international experts from five continents (Africa, Europe, Asia, Oceania, America) concerning optimal follow-up strategies in patients with splenic injuries treated with NOM.

Results

Consensus was reached on eleven clinical research questions and 28 recommendations with an agreement rate ≥ 80%. Mobilization after 24 h in low-grade splenic trauma patients (WSES Class I, AAST Grades I–II) was suggested, while in patients with high-grade splenic injuries (WSES Classes II–III, AAST Grades III–V), if no other contraindications to early mobilization exist, safe mobilization of the patient when three successive hemoglobins 8 h apart after the first are within 10% of each other was considered safe according to the panel. The panel suggests adult patients to be admitted to hospital for 1 day (for low-grade splenic injuries—WSES Class I, AAST Grades I–II) to 3 days (for high-grade splenic injuries—WSES Classes II–III, AAST Grades III–V), with those with high-grade injuries requiring admission to a monitored setting. In the absence of specific complications, the panel suggests DVT and VTE prophylaxis with LMWH to be started within 48–72 h from hospital admission. The panel suggests splenic artery embolization (SAE) as the first-line intervention in patients with hemodynamic stability and arterial blush on CT scan, irrespective of injury grade. Regarding patients with WSES Class II blunt splenic injuries (AAST Grade III) without contrast extravasation, a low threshold for SAE has been suggested in the presence of risk factors for NOM failure. The panel also suggested angiography and eventual SAE in all hemodynamically stable adult patients with WSES Class III injuries (AAST Grades IV–V), even in the absence of CT blush, especially when concomitant surgery that requires change of position is needed. Follow-up imaging with contrast-enhanced ultrasound/CT scan in 48–72 h post-admission of trauma in splenic injuries WSES Class II (AAST Grade III) or higher treated with NOM was considered the best strategy for timely detection of vascular complications.

Conclusion

This consensus document could help guide future prospective studies aiming at validating the suggested strategies through the implementation of prospective trauma databases and the subsequent production of internationally endorsed guidelines on the issue.

Immune Function After Splenic Artery Embolization for Blunt Trauma: Long-Term Assessment of CD27+ IgM B-Cell Levels

Splenic artery embolization (SAE) plays a critical role in the treatment of high-grade splenic injury not requiring emergent laparotomy. SAE preserves splenic tissue, and growing evidence demonstrates preserved short-term splenic immune function after SAE. However, long-term function is less studied. Patients who underwent SAE for blunt abdominal trauma over a 10-year period were contacted for long-term follow-up. Sixteen participants (sex: women, 10, and men, 6; age: median, 34 years, and range, 18-67 years) were followed up at a median of 7.7 years (range, 4.7-12.8 years) after embolization. Splenic lacerations were of American Association for the Surgery of Trauma grades III to V, and 14 procedures involved proximal embolization. All individuals had measurable levels of IgM memory B cells (median, 14.30 as %B cells), splenic tissue present on ultrasound (median, 122 mL), and no history of severe infection since SAE. In conclusion, this study quantitatively demonstrated that long-term immune function remains after SAE for blunt abdominal trauma based on the IgM memory B cell levels.

Immune function and the role of vaccination after splenic artery embolization for blunt splenic injury

The spleen is the most commonly injured solid organ following blunt abdominal trauma. Over recent decades, splenic artery embolization (SAE) has become the mainstay treatment for haemodynamically stable patients with high-grade blunt splenic trauma, with splenectomy the mainstay of treatment for unstable patients. Splenic function is complex but the spleen has an important role in immune function, particularly in protection against encapsulated bacteria. Established evidence suggests that following splenectomy immune function is impaired resulting in increased susceptibility to overwhelming post-splenectomy infection, however, immune function may be preserved following SAE. This review will discuss the current state of the literature on immune function following different treatments of blunt splenic injury, and the controversies surrounding what constitutes a quantitative test of splenic immune function.

Splenic trauma: endovascular treatment approach

The spleen is a commonly injured organ in blunt abdominal trauma. Splenic preservation, however, is important for immune function and prevention of overwhelming infection from encapsulated organisms. Splenic artery embolization (SAE) for high-grade splenic injury has, therefore, increasingly become an important component of non-operative management (NOM). SAE decreases the blood pressure to the spleen to allow healing, but preserves splenic perfusion via robust collateral pathways. SAE can be performed proximally in the main splenic artery, more distally in specific injured branches, or a combination of both proximal and distal embolization. No definitive evidence from available data supports benefits of one strategy over the other. Particles, coils and vascular plugs are the major embolic agents used. Incorporation of SAE in the management of blunt splenic trauma has significantly improved success rates of NOM and spleen salvage. Failure rates generally increase with higher injury severity grades; however, current management results in overall spleen salvage rates of over 85%. Complication rates are low, and primarily consist of rebleeding, parenchymal infarction or abscess. Splenic immune function is felt to be preserved after embolization with no guidelines for prophylactic vaccination against encapsulated bacteria; however, a complete understanding of post-embolization immune changes remains an area in need of further investigation. This review describes the history of SAE from its inception to its current role and indications in the management of splenic trauma. The endovascular approach, technical details, and outcomes are described with relevant examples. SAE is has become an important part of a multidisciplinary strategy for management of complex trauma patients.

Splenic Artery Embolization for Patients with High-Grade Splenic Trauma: Indications, Techniques, and Clinical Outcomes

The spleen is the most commonly injured organ in blunt abdominal trauma. Patients who are hemodynamically unstable due to splenic trauma undergo definitive operative management. Interventional radiology plays an important role in the multidisciplinary management of the hemodynamically stable trauma patient with splenic injury. Hemodynamically stable patients selected for nonoperative management have improved clinical outcomes when splenic artery embolization is utilized. The purpose of this article is to review the indications, technical aspects, and clinical outcomes of splenic artery embolization for patients with high-grade splenic injuries.

Immunization coverage among asplenic patients and strategies to increase vaccination compliance: a systematic review and meta-analysis

BACKGROUND

Asplenic or splenectomized patients have a higher risk (ranging from 10 to 50-fold) than the general population of developing an overwhelming post-splenectomy infection (OPSI). Thus, they should receive specific vaccinations to prevent bacterial infections and influenza. The aim of this meta-analysis was to estimate vaccination coverage (VC) with the recommended vaccines among splenectomized patients; strategies recommended in those studies to improve VC worldwide are considered as well.

RESEARCH DESIGN AND METHODS

Scopus, MEDLINE/PubMed, Google Scholar and ISI Web of Knowledge databases were searched. Research papers, short reports, reviews, and meta-analyses published between January 1, 2010 and July 18, 2020 were included; no geographic restrictions were included. Twenty-four studies were included in the meta-analysis.

RESULTS

For anti-pneumococcal vaccination, coverage was 55.1% (95%CI = 41.0-69.2%), for anti-Hib 48.3% (95%CI = 34.3-52.3%), for anti-meningococcal C/ACYW135 33.7% (95%CI = 23.6-43.9%), for anti-meningococcal B 13.3% (95%CI = 7.0-19.5%) and for anti-influenza 53.2% (95%CI = 22.0-84.4%). Most studies determined a lack of adherence to international guidelines by healthcare workers and suggested the need to better educate health professionals in the management of post-splenectomy patients.

CONCLUSIONS

The meta-analysis showed the suboptimal immunization coverage for the vaccines recommended for asplenic patients. Greater efforts must be made by public health professionals to increase VC in this group of patients at risk. Introducing specific prophylaxis protocols in the clinical routine seems to guarantee better immunization compliance in those patients.

Splenic artery embolisation in trauma: A five-year single-centre experience at a UK major trauma centre

Introduction

Since the introduction of major trauma centres and regional trauma networks in 2012, management of splenic injury has shifted, with non-operative management now favoured. For those requiring intervention, splenic artery embolisation is well established as a first-line treatment in all but the most severely injured. Follow-up is variable, with few guidelines, highlighting the paucity of data addressing the need for further imaging and antimicrobial prophylaxis. This review was undertaken to assess practice and outcomes at our centre in the context of the contemporary literature.

Methods

This retrospective study captured splenic embolisations over five years (January 2012–December 2016). CRIS interventional radiology codes were used to retrieve embolisation cases and Trauma Audit and Research Network and hospital event statistics data were used to identify all cases of traumatic splenic injury and to identify splenectomy and non-operative management patients. Outcomes were compared with available standards from different sources.

Results

Over the study period 176 splenic injuries were identified, of which 122 underwent non-operative management, 28 were laparotomy first, and 26 undergoing embolisation with an increased trend to an ‘embolisation-first’ approach over this time. In the embolisation group, the age range was 16–79 yr (mean 41), 18 were male and the median time to intervention was 2 h 9 min (range 1.1–171 h), with eight following failed non-operative management. The proportion of proximal versus selective embolisation versus both was 10:14:1 and the predominant mechanism was coiling. One patient was not embolised due to absence of contrast extravasation on initial angiogram and two proceeded to splenectomy due to failure of splenic artery embolisation. There were complications in six patients: five ongoing left upper quadrant pain, one infected haematoma requiring drainage, two chest infections with pleural effusions, one of which required drainage. There were two deaths from other injuries. Fifteen of the 25 patients who underwent splenic artery embolisation had follow-up imaging, seven did not and three were excluded due to splenectomy and/or death; five patients were vaccinated according to the hospital splenectomy protocol, and six received prophylactic antibiotics.

Conclusion

Our data show that non-operative management is the mainstay of treatment for the majority of splenic injury patients. Serious complications are not common but variation does exist in follow-up. The changing management trends are in line with national data. These findings will help to further implement and develop local protocols but more work is required to address splenic function after embolisation and the requirement for antimicrobial prophylaxis.

Outcomes Following Blunt Traumatic Splenic Injury Treated with Conservative or Operative Management

INTRODUCTION

Laparotomy, embolization, and observation are described for blunt splenic injury management. This study evaluated outcomes of blunt splenic injury management based on baseline factors, splenic injury severity, and associated injuries.

METHODS

A nine-year retrospective review was conducted of adult patients with blunt splenic injury. Collected data included demographics, injury characteristics, treatment modality, complications, and outcomes (mechanical ventilation, days on mechanical ventilation, intensive care unit [ICU] admission and length of stay, hospital length of stay, and in-hospital mortality). Categorical and continuous variables were analyzed using χ² analysis and one-way analysis of variance for normally distributed variables and a non-parametric test of medians for variables that did not meet the assumption of normality, respectively.

RESULTS

Splenic injury grade was similar between operative and embolization groups, but severe hemoperitoneum was more common in the operative group. Complications and mortality were highest in the operative group (50.7% and 26.3%, respectively) and lowest in the embolization group (5.3% and 2.6%, respectively). Operative patients required more advanced interventions (ICU admission, mechanical ventilation). There were no differences between those treated with proximal versus distal embolization. Observation carried a failure rate of 11.2%, with no failures of embolization.

CONCLUSIONS

Embolization patients had the lowest rates of complications and mortality, with comparable splenic injury grades to those treated operatively. Further prospective research is warranted to identify patients that may benefit from early embolization and avoidance of major abdominal surgery.

Non-operative management of blunt hepatic and splenic injury: a time-trend and outcome analysis over a period of 17 years

Background

A widespread shift to non-operative management (NOM) for blunt hepatic and splenic injuries has been observed in most centers worldwide. Furthermore, many countries introduced safety measures to systematically reduce severe traffic and leisure sports injuries. This study aims to evaluate the effect of these nationwide implementations on individual patient characteristics and outcomes through a time-trend analysis over 17 years in an Austrian high-volume trauma center.

Methods

A retrospective review of all emergency trauma patients admitted to the Medical University of Innsbruck from 2000 to 2016. Injury severity, clinical data on admission, operative and non-operative treatment parameters, complications, and in-hospital mortality were evaluated.

Results

In total, 731 patients were treated with blunt hepatic and/or splenic injuries. Among these, 368 had a liver injury, 280 splenic injury, and 83 combined hepatic/splenic injury. Initial NOM was performed in 82.6% of all patients (93.5% in hepatic and 71.8% in splenic injuries) with a success rate of 96.7%. The secondary failure rate of NOM was 3.3% and remained consistent over 17 years (p = 0.515). In terms of injury severity, we observed a reduction over time, resulting in an overall mortality rate of 4.8% and 3.5% in the NOM group (decreasing from 7.5 to 1.9% and from 5.6 to 1.3%, respectively). These outcomes confirmed an improved utilization of the NOM approach.

Conclusion

Our cohort represents one of the largest Central European single-center experiences available in the literature. NOM is the standard of care for blunt hepatic and splenic injuries and successful in > 96% of all patients. This rate was quite constant over 17 years (p = 0.515). Overall, national and regional safety measures resulted in a significantly decreased severity of observed injury patterns and deaths due to blunt hepatic or splenic trauma. Although surgery is nowadays only applied in about one third of splenic injury patients in our center, these numbers might further decrease by intensified application of interventional radiology and modern coagulation management.

Electronic supplementary material

The online version of this article (10.1186/s13017-019-0249-y) contains supplementary material, which is available to authorized users.

Review of proximal splenic artery embolization in blunt abdominal trauma

The spleen is the most commonly injured organ in blunt abdominal trauma. Unstable patients undergo laparotomy and splenectomy. Stable patients with lower grade injuries are treated conservatively; those stable patients with moderate to severe splenic injuries (grade III-V) benefit from endovascular splenic artery embolization. Two widely used embolization approaches are proximal and distal splenic artery embolization. Proximal splenic artery embolization decreases the perfusion pressure in the spleen but allows for viability of the spleen to be maintained via collateral pathways. Distal embolization can be used in cases of focal injury. In this article we review relevant literature on splenic embolization indication, and technique, comparing and contrasting proximal and distal embolization. Additionally, we review relevant anatomy and discuss collateral perfusion pathways following proximal embolization. Finally, we review potential complications of splenic artery embolization.

Non-operative management of blunt hepatic and splenic injuries-practical aspects and value of radiological scoring systems

Background

Non-operative management (NOM) of blunt hepatic and splenic injuries has become popular in haemodynamically stable adult patients, despite uncertainty about efficacy, patient selection, and details of management. Up-to-date strategies and practical recommendations are presented.

Methods

A selective literature search was conducted in PubMed and the Cochrane Library (1989–2016).

Results

No randomized clinical trial was found. Non-randomized controlled trials and large retrospective and prospective series dominate. Few systematic reviews and meta-analyses are available. NOM of selected patients with blunt liver and spleen injuries is associated with low morbidity and mortality. Only data of limited evidence are available on intensity and duration of patient monitoring, repeat imaging, antithrombotic prophylaxis and return to normal activity. There is high-level evidence on early mobilisation and post-splenectomy vaccination.

Conclusion

NOM of blunt liver or spleen injuries is a worldwide trend, but the literature does not provide high-grade evidence for this strategy.

Divergent humoral responses to 23-valent pneumococcal polysaccharide vaccine in critically-ill burn and neurosurgical patients

INTRODUCTION

Critically ill hospitalized patients are at increased risk of infection so we assessed the immunogenicity of 23-valent pneumococcal polysaccharide vaccine (PPSV23) administered within six days of injury.

METHODS

This prospective observational study compared the immunogenicity of PPSV23 among critically ill burn and neurosurgical patients at a tertiary, academic medical center. Patients received PPSV23 vaccination within six days of ICU admission per standard of care. Consent was obtained to measure concentrations of vaccine-specific IgG to 14 of 23 serotype capsule-specific IgG in serum prior to and 14-35 days following PPSV23. A successful immunologic response was defined as both a ≥2-fold rise in capsule-specific IgG from baseline and concentrations of >1 mcg/mL to 10 of 14 measured vaccine serotypes. Immunologic response was compared between burn and neurosurgical patients. Multiple variable regression methods were used to explore associations of clinical and laboratory parameters to immunologic responses.

RESULTS

Among the 16 burn and 27 neurosurgical patients enrolled, 87.5% and 40.7% generated a successful response to the vaccine, respectively (p = 0.004). Both median post-PPSV23 IgG concentrations (7.79 [4.56-18.1] versus 2.93 [1.49-8.01] mcg/mL; p = 0.006) and fold rises (10.66 [7.44-14.56] versus 3.48 [1.13-6.59]; p<0.001) were significantly greater in burn compared with neurosurgical patients. Presence of burn injury was directly and days from injury to immunization were inversely correlated with successful immunologic response (both p<0.03). Burn injury was associated with both increased median antibody levels post-PPSV23 and fold rise to 14 vaccine serotypes (p<0.03), whereas absolute lymphocyte count was inversely correlated with median antibody concentrations (p = 0.034).

CONCLUSION

Critically ill burn patients can generate successful responses to PPSV23 during acute injury whereas responses among neurosurgical patients is comparatively blunted. Further study is needed to elucidate the mechanisms of differential antigen responsiveness in these populations, including the role of acute stress responses, as well as the durability of these antibody responses.

Partial Splenic Artery Embolization to Treat Hypersplenism Secondary to Hepatic Cirrhosis: A Meta-Analysis

This meta-analysis aimed to explore the effectiveness of partial spleen arterial embolization (PSAE) in the treatment of hypersplenism secondary to hepatic cirrhosis. PubMed, Embase, Cochrane Library, Wan Fang, CNKI, Vip, and CBM databases were searched for randomized controlled trials, cohort studies, and case–control studies that compared PSAE with splenectomy in the treatment of hypersplenism secondary to hepatic cirrhosis from their inception to July 25, 2015. Statistical analysis was conducted in Cochrane Network RevMan v5.3. Primary outcomes included the pre- and postoperative platelet and leukocyte counts and hemoglobin levels. Secondary outcomes were operative time, intraoperative volume of bleeding, and length of hospital stay. Mean and standard deviation were obtained from each study and then pooled using fixed- or random-effects models to calculate the mean difference. Ten original studies investigating 737 patients were included. Both the PSAE group and the splenectomy group yielded higher postoperative platelet and leukocyte counts and hemoglobin levels than the preoperative. The difference of platelet and leukocyte counts and hemoglobin levels between postoperative and preoperative levels in the PSAE group was smaller than that in the splenectomy group. Besides, compared with the splenectomy group, the PSAE group exhibited shorter operative time, less intraoperative bleeding, and shorter length of stay. PSAE is a mini-invasive therapy, which can be applied to treat hypersplenism secondary to hepatic cirrhosis effectively, particularly for patients with a poor overall condition. However, further high-quality studies should be conducted because this meta-analysis is limited by the quality of studies and the large statistical heterogeneity.

Evidence-Based Management and Controversies in Blunt Splenic Trauma

PURPOSE OF REVIEW

The study aims to describe the evidence-based management and controversies in blunt splenic trauma.

RECENT FINDINGS

A shift from operative management to non-operative management (NOM) has occurred over the past decades where NOM has now become the standard of care in haemodynamically stable patients with blunt splenic injury. Splenic artery embolisation (SAE) is generally believed to increase the success rate of NOM. Not all the available evidence is that optimistic about SAE however. A morbidity specifically related to SAE of up to 47% has been reported. Although high-grade splenic injury is a prognostic factor for failure of NOM, an American research group has published a study in which NOM is performed in over half of haemodynamically stable patients with grade IV or V splenic injury without leading to an increased morbidity (in terms of complications) or mortality. Another area of current investigation in the literature is the exact indication for SAE. Although the generally accepted indication is the presence of vascular injury, a topic of current investigation is whether there might be a role for pre-emptive embolisation in patients with high-grade splenic injury. On the other hand, evidence is also emerging that not all blushes require an intervention (small blushes <1 or 1.5 cm do not). Lastly, the available evidence shows that splenic function is preserved after embolisation, and therefore, the routine administration of vaccinations seems not to be necessary. There might be a difference between proximal and distal embolisations; however, with regard to splenic function, in favour of distal embolisation.

SUMMARY

Nowadays, NOM is the standard of care in haemodynamically stable patients with blunt splenic injury. The available evidence (although with a relatively small number of patients) shows that splenic function is preserved after NOM, a major advantage compared to splenectomy. SAE is used as an adjunct to observation in order to increase the success rate of NOM. Operative management should be applied in case of haemodynamic instability or if associated intra-abdominal injuries requiring surgical treatment are present. Patient selection (which patient can be safely treated non-operatively, does every blush needs to be embolised?, which patients might be better off with direct operative intervention given the patient and injury characteristics) is an ongoing subject of further research. Future studies should also focus on long-term outcomes of patients treated with embolisation (e.g. total number of lifetime infectious episodes requiring antibiotic treatment or hospital admission, quality of life).

Splenic function after angioembolization for splenic trauma in children and adults: A systematic review

PURPOSE

Splenic artery embolization (SAE), proximal or distal, is becoming the standard of care for traumatic splenic injury. Theoretically the immunological function of the spleen may be preserved, but this has not yet been proven. A parameter for measuring the remaining splenic function must therefore be determined in order to decide whether or not vaccinations and/or antibiotic prophylaxis are necessary to prevent an overwhelming post-splenectomy infection (OPSI).

METHODS

A systematic review of the literature was performed July 2015 by searching the Embase and Medline databases. Articles were eligible if they described at least two trauma patients and the subject was splenic function. Description of procedure and/or success rate of SAE was not necessary for inclusion. Two reviewers independently assessed the eligibility and the quality of the articles and performed the data extraction.

RESULTS

Twelve studies were included, eleven with adult patients and one focusing on children. All studies used different parameters to assess splenic function. None of them reported a OPSI after splenic embolization. Eleven studies found a preserved splenic function after SAE, in both adults and children.

CONCLUSION

All but one studies on the long term effects of SAE indicate a preserved splenic function. However, there is still no single parameter or test available which can demonstrate that unequivocally.

Splenic Arterial Embolization in the Treatment of Severe Portal Hypertension Due to Pancreatic Diseases: The Primary Experience in 14 Patients

Objective

This retrospective study reports our experience using splenic arterial particle embolization and coil embolization for the treatment of sinistral portal hypertension (SPH) in patients with and without gastric bleeding.

Methods

From August 2009 to May 2012, 14 patients with SPH due to pancreatic disease were diagnosed and treated with splenic arterial embolization. Two different embolization strategies were applied; either combined distal splenic bed particle embolization and proximal splenic artery coil embolization in the same procedure for acute hemorrhage (1-step) or interval staged distal embolization and proximal embolization in the stable patient (2-step). The patients were clinically followed.

Results

In 14 patients, splenic arterial embolization was successful. The one-step method was performed in three patients suffering from massive gastric bleeding, and the bleeding was relieved after embolization. The two-step method was used in 11 patients, who had chronic gastric variceal bleeding or gastric varices only. The gastric varices disappeared in the enhanced CT scan and the patients had no gastric bleeding during follow-up.

Conclusions

Splenic arterial embolization, particularly the two-step method, proved feasible and effective for the treatment of SPH patients with gastric varices or gastric variceal bleeding.