Pelvic packing was originally performed using a trans-abdominal approach after laparotomy but with poor results, due to that the disruption of intact peritoneum was attempting to affect tamponade of hemorrhage, leading to aggravation of bleeding [4, 14]. The technique had been changed by Pohlemann et al. [10] in 1994 to packing of retroperitoneum and then modified to ensure direct packing of the pelvic space through a preperitoneal approach [24]. The method is usually performed by making an infra-umbilical midline incision of about 6–8 cm. Skin, subcutaneous tissue and fascia are dissected without violating the peritoneal cavity. Three laparotomy pads are placed below the pelvic brim toward the iliac vessels on each side of bladder [25]. The revision of PP should be done within 48–72 h [26].
After the modification in 1994, PP has been widely used in European trauma centers as a salvage procedure in the management for hemodynamically unstable patients with pelvic fractures [11, 12, 27–29]. Frassini et al. described PP as a life-saving procedure which could be the first step of a multidisciplinary management of pelvic ring disruptions [12]. In the First Italian Consensus Conference, statement agreed the effectiveness of PP and proposed an algorithm in which PP was prior to angiography [30]. Aside from Europe, in the last decade, scholars from China and South Korea reported improved clinical outcomes since adopting PP in the in the initial treatment protocol [11, 15, 17, 18]. World Society of Emergency Surgery (WSES) guidelines in 2017, recommend that PP should always be considered for patients with pelvic fracture-related hemodynamic instability and maximized effectiveness could be achieved when combined with external fixation [26].
However, surgeons in North America seem to be more in favor of angiography and embolization [31]. In guidelines from both Eastern Association for the Surgery of Trauma (EAST) and Western Trauma Association in the Unites States, angiography remains the mainstay of therapy [32–34]. A multicenter, observational study conducted through the American Association for the Surgery of Trauma (AAST) in 2015, enrolling patients from 11 Level I trauma centers, demonstrated that angioembolization and external fixator placement were the most common method for pelvic hemorrhage [35]. The mortality rate was 32% in AAST series of pelvic fracture patients in shock [35]. Another modern series in the US revealed that the mortality rate was 27.8% in patients with hemorrhagic instability and undergoing angiography [31]. Yet in 2016, Burlew et al. in Denver, USA, reported a mortality rate of 21% in an 11-year single-center study with a modified protocol which considered PP as the first intervention for pelvic fracture hemorrhage [36]. Burlew’s group had been continuing sharing their results since adopting PP in treatment protocol in 2004 [13, 24, 36]. Their long-term observational study confirmed that PP reduces mortality compared with other series favoring angiography and embolization, recommending that PP should be used for pelvic fracture patients with unstable hemodynamics [36]. The updated algorithm by Western Trauma Association in 2016 also attached more importance to the use of PP [33].
Pelvic packing has the advantage of lowered mortality and reduced time to intervention [15, 17, 18, 36], but results varied in different researches [3, 6, 14]. Its role in the management of pelvic hemorrhage remains controversial and needs more studies with feasible comparison like angiography. This article includes all current comparative studies and to our knowledge, containing the largest number of patients. Only four of the included studies demonstrated that the implementation of PP in management protocol significantly improved survival [11, 12, 15, 17]. The previous relatively small cohorts may lead to results with low credibility. Death within the first 24 h after admission is commonly due to exsanguination, whereas, mortality after 24 h is usually from multiple organ failure [10, 37]. Different groups showed that the improvement through PP in mortality within 24 h or due to hemorrhage might be more marked than the improvement in overall mortality [11, 12, 15, 17]. Our quantitative synthesis confirmed this finding and we believe the early use of PP is a life-saving procedure in management for patients in hemorrhagic shock.
Delay in hemostatic procedures is associated with increased mortality in patients with pelvic hemorrhage [12]. Every 3 minutes of delay in the resuscitation room leads to a 1% mortality increase in a hemodynamically unstable patient with blunt abdominal trauma in the first 90 minutes [38]. Early hemostasis should be done as soon as possible.
Currently, angiography is still considered the first choice of hemorrhage control in most institutional algorithms [23]. However, the time required for transportation of patients, preparation of angiography suite and mobilization of trained interventional radiologists is excessive. In contrast, PP can be quickly accomplished either in operation or emergency room [11, 12]. Osborn et al. reported a mean time to PP of 44 minutes from the emergency department (ED) admission, compared to a mean of 130 minutes to the angiography suite [6]. Average time to operative packing reported from Tai et al. was 79 minutes compared with 140 minutes to angiography [14]. Similar results were shown by Jang et al, with time to intervention in PP group was 55 minutes compared to 194 minutes in Non-PP group [16]. Our previous results also reported that PP had shorter procedure duration than angiography [3]. Recently, a study from Italy demonstrated that the total hemostatic procedure time was sharply reduced for patients in PP group, with a mean time of 49 minutes compared to 156 minutes in the No-PP group [12]. Considering lots of studies have confirmed that PP has the advantage of immediacy and rapidity [3, 6, 12, 14, 16, 17, 23, 36], we didn’t perform a quantitative analysis for that.
Except for consuming time, the availability of angiography varies in hospitals. Low-level trauma centers, especially in remote or rural region, may be not equipped with qualified angiography suite. Meanwhile, interventional radiologists are not in-house at all times [3], and interventions are easily to be delayed during nights and weekends [39]. Metcalfe et al. reported that a 24 h formal interventional radiology service was only available at 18% of hospitals in Wales, UK [40]. PP is a fast and easy procedure with a low demand for equipment and short learning curve, deserving a more widespread use. Moreover, the high energy trauma causing pelvic fractures often lead to increased risk of associated injuries. Additionally, three or more procedures are required to address these injuries [36]. The rapid arrestment of hemorrhage by PP facilitates other emergent operative procedures to stabilize polytrauma patients [15].
Pathophysiologically, PRBCs may induce the adverse inflammatory responses by activating inflammatory genes in circulating leukocytes [41]. Wong et al. reported an increased mortality rate by 62% for every one PRBC unit per hour increase of transfusion rate [42]. Since the need of transfusion is associated with increased ICU length of stay, multiple organ failure and mortality, reducing transfusion is a compelling objective [13]. With PP included in protocol, though the total number of transfusions required in the first 24 h after admission wasn’t changed, the need of transfusion in ED was significantly reduced. We think the reduced time to intervention for PP is critical to the decreased need of pre-operative transfusion. Osborn et al. reported that packing significantly decreased blood transfusion over the 24 h post-intervention period whereas the angiography demonstrated no such change [6]. Burlew’s group also reported a significant reduction in transfusion requirement after PP [13, 36]. This decrease may be attributed to the concurrent management of associated injuries that could otherwise contribute to continuous bleeding [6]. However, our previous study as well as report from Tai et al. demonstrated post-intervention transfusion was similar in patients treated with PP or angiography [3, 14]. On account of inadequate data, we failed to perform a quantitative analysis. Further studies are needed to determine the role PP plays in blood transfusion requirement.
Though most pelvic hemorrhage originates from veins or fractured bones, a combined injury involving both intra-pelvic veins and arteries is not uncommon [28]. Also high rate of arterial injury was found in patients after PP [23]. Despite that the use of PP improves survival; it cannot completely replace angiography and embolization. During initial resuscitation of pelvic trauma, it is difficult to ascertain the accurate source of bleeding [14] so the optimal procedure may be hard to determine in short time. Since the primary source of pelvic bleeding is injured veins or fractured bone and angiography is time-consuming, PP should be considered as the first-line treatment for pelvic fracture patients with unstable hemodynamics. If patients sustained hemodynamically unstable after PP, arterial bleeding should be suspected and angiography is necessary. A complementary association of pelvic packing and endovascular procedures seems to be the best clinical practice based on guidelines from WSES and Western Trauma Association [12]. Suzuki et al. proposed PP as the primary procedure for patients with unstable hemodynamics, whereas angiography could be the first choice in stabilized patients [43]. Totterman et el. reported high rate of arterial injury observed on angiography after PP and suggested that PP should be supplemented with angiography once sufficient hemodynamic stability had been attained [28]. To some extent, PP could be a time-gaining ‘bridge technique’ to angiography and embolization [12]. It should be pointed out that, based on current evidence, it is unclear whether secondary angiography should be performed on all patients or just on those who still has a manifestation of continuous bleeding after PP.
In recent years, resuscitative endovascular balloon occlusion of the aorta (REBOA) has been proposed as an alternative for temporary bleeding control in hemodynamically unstable trauma patients [26]. REBOA has the advantage of a rapid and effective control of arterial hemorrhage with preservation of cerebral and myocardial perfusion [33]. Its usage in patients with pelvic trauma has been increasing especially in the USA. WSES guidelines and Western Trauma Association suggested that REBOA may act as an effective adjunct in the management of hemodynamically unstable pelvic ring injuries [26, 33]. However, the occlusion time is associated with ischemia-reperfusion injury and amputation. Currently, REBOA is mainly considered as a bridge from emergent hemostasis to secondary procedure [12] and more studies of high quality are needed.
This study has both strengths and limitations. The strength lies in the large member of enrolled patients. Several limitations are listed as following. First, only two of the included studies were prospective study and no randomized controlled trial was included. However, a randomized study was not reasonable in light of ethical and practical reasons. Second, there was limited data for accessing transfusion requirement. Third, Propensity Score Matching (PSM) Analysis was used to adjust the differences in the baseline characteristics between the two groups in two studies [11, 12] and we only enrolled patients after PSM. The neglected data may likely affect the strength of conclusions.