Although the estimate for the mortality rate of pelvic fractures is less than 20%,1,2 the estimate for the mortality rate of hemodynamically unstable pelvic fractures is as high as 40% to 60%.2–4 The cause of death in these cases is exsanguination. Venous lacerations, fractured bone surfaces, and arterial lacerations are the major bleeding sites associated with pelvic fractures. Treatments for pelvic fractures comprise a combination of mechanical stabilization and arterial embolization for the control of bleeding from the fractured bone surface and the lacerated artery. However, it has been reported that venous hemorrhage accounts for most bleeding (approximately 85%) in patients with pelvic fracture.5
The basic strategy of pelvic packing for the control of venous bleeding was first described in 2001 in a report from Europe and involved a transabdominal method.6 In 2005, application of retroperitoneal pelvic packing was first reported in the United States.7 Subsequently, several facilities have reported on the effectiveness of a multimodality treatment involving angioembolization, pelvic packing, and external fixation.8–12 Moreover, the Eastern Association for the Surgery of Trauma guideline established in 2011 stated that retroperitoneal pelvic packing is effective for controlling hemorrhage when used as part of a multidisciplinary clinical pathway that includes angiographic embolization and the use of a pelvic orthotic device/C-clamp.13 The 2016 European guideline on management of major bleeding and coagulopathy following trauma also recommends that hemodynamically unstable patients receive pelvic packing even after adequate pelvic ring stabilization.14
Nevertheless, it remains unclear whether retroperitoneal pelvic packing itself is effective for hemorrhage control in patients with pelvic fracture trauma. Indeed, the report of the American Association for the Surgery of Trauma (AAST) regarding a multi-institutional trial mentioned that retroperitoneal pelvic packing is used relatively rarely.15 To clarify this aspect, retroperitoneal pelvic packing would need to be directly compared with angiography and external fixation in terms of the control of pelvic hemorrhage. However, such a study would be difficult due to ethical considerations preventing the application of treatment that has not been confirmed as effective.
Using a cadaver model, the authors aimed to assess whether retroperitoneal pelvic packing generates pressure that exceeds the central venous pressure and to verify how many sponges would be required to achieve this pressure, as up to 3 surgical sponges were mentioned in the original report on pelvic packing.7 The authors expected to find that pelvic packing would create pressure on the pelvic walls in the pelvic cavity that exceeded venous pressure, providing evidence for the effectiveness of pelvic packing alone for the control of pelvic hemorrhage.
Materials and Methods
Study Design Overview
Pelvic pressure was assessed after the placement of 1 to 3 sponges in 5 cadaveric specimens. Because the cable of the pressure gauge crosses over the soft tissue during a bilateral measurement, measurement was performed only on one side. Specifically, the pressure was measured on the right side with packing, after having packed the left side without measuring pressure.
Five fresh, unembalmed male Japanese cadaveric specimens were used. All donors had agreed to dissection of their body for research purposes and died between April 2013 and March 2015. Average specimen age was 88 years (range, 79–95 years), which was high because life expectancy among Japanese donors is high in general. The specimens were refrigerated before the study for an average of 5 days. None of the specimens had a history of pelvic disease or injury to the pelvic bone.
All experiments were performed based on the Japanese guidelines for cadaver dissection, established in 2012 by the Japan Surgical Society and the Japanese Association of Anatomists. The experiments were also approved by the ethics committee of the authors' university.
The authors used a portable interface pressure sensor as a pressure gauge (PalmQ; CAPE Co, Ltd, Kanagawa, Japan), which is routinely used for measuring pressure on the buttocks for bedsore prevention. This 169 cm2 can measure pressure levels from 0 to 200 mm Hg (±3 mm Hg), and has 5 sensors (2.5 cm in diameter) that can simultaneously measure the pressure at 5 points.
Retroperitoneal Pelvic Packing Procedure
With the specimen in a supine position, a midline incision was made from the umbilicus to the symphysis pubis. The sub-cutaneous tissue and the anterior fascia of the rectus abdominis muscle were incised in the midline. The bladder was retracted to one side and the pelvic brim was palpated from the symphysis in a posterior direction toward the sacroiliac joint on the other side.
At first, the pressure gauge was placed against the pelvic cavity wall, and calibration was performed. Then, the first 900 cm2 surgical sponge (Opeze X; Hakujuji Co, Ltd, Tokyo, Japan) was folded in fourths and placed posterior, just below the sacroiliac joint. The second sponge was folded in fourths and placed anterior to the first sponge, in the middle of the pelvic brim. The third sponge was also folded in fourths and placed just lateral to the bladder (Figure 1). This procedure was based on the original retroperitoneal pelvic packing procedure, which is described in detail elsewhere.7
Scheme depicting the pressure gauge and surgical procedure. Pressure gauge installation (A). After creating space for the retroperitoneal pelvic packing procedure, the pressure gauge was placed along the pelvic wall so that the sensor line overlapped diagonally with the pelvic brim. One sensor was placed along the abdominal wall, outside the pelvic cavity. Surgical sponges were inserted from posterior to anterior (B).
The pressure gauge was placed in the space of the pelvic cavity so that the posterior sensor was attached to the pelvic floor and the middle 3 sensors were attached to the pelvic brim (Figure 1). The pressure value of the anterior sensor was excluded from the analysis because it was placed outside of the pelvic cavity. Before pressure measurement, the authors checked that the default pressure was zero at all sampling points. The first surgical sponge was placed and pressures were measured, with the skin closed via sutures. The second sponge was placed and pressures were again measured. Finally, the third sponge was placed and pressures were measured. The authors analyzed the values of the individual sensors and the mean value across the 4 sensors placed inside the pelvic cavity.
Comparisons among the average pressures for the 4 sensor points in each specimen were performed using the Kruskal–Wallis one-way analysis of variance. For each sensor point, the average pressure generated by inserting a given number of sponges (1, 2, or 3 sponges) was compared using the Friedman test for paired samples. Statistical analysis was performed using the SPSS software package for Macintosh, version 22 (SPSS, Chicago, Illinois). P<.05 was considered statistically significant.
Average pressure in the pelvic cavity across all specimens was 7.17 mm Hg for 1 sponge, 11.38 mm Hg for 2 sponges, and 12.28 mm Hg for 3 sponges. Pressure increased significantly with the number of sponges (Friedman test for paired samples: P=.041; Figure 2). A quadratic curve approximation showed that the pressure peaked when 3 surgical sponges were inserted.
Bar graph showing the average pressure across all 4 sites, for each specimen and each number of packing sponges. Symbols indicate specimen number: specimen 1, ■; specimen 2, ♦; specimen 3, ▲; specimen 4, ×; and specimen 5, +. The mean pressure across all 5 specimens (○) is also shown, with error bars indicating standard deviation.
Average pressure on the pelvic floor was 9.18 mm Hg for 1 sponge, 16.22 mm Hg for 2 sponges, and 17.6 mm Hg for 3 sponges. Average pressure on the pelvic posterior brim was 2.44 mm Hg for 1 sponge, 15.06 mm Hg for 2 sponges, and 12.56 mm Hg for 3 sponges. The pressure on the pelvic floor and pelvic posterior brim increased significantly with the insertion of each additional surgical sponge (Friedman test for paired samples: P=.016 and P=.015, respectively; Figures 3A–B). Although inserting additional surgical sponges increased the pressure on the anterior and middle pelvic brim, the increase was not statistically significant (P=1.000 and P=.223, respectively; Figures 3C–D).
Bar graph showing the relationship between the number of packed sponges and the pressure recorded at each sensor location for each of 5 specimens. Pelvic floor pressure (A). Posterior pelvic brim pressure (B). Anterior pelvic brim pressure (C). Middle pelvic brim pressure (D). Symbols indicate specimen number: specimen 1, ■; specimen 2, ♦; specimen 3, ▲; specimen 4, ×; and specimen 5, +. The mean pressure across all 5 specimens (○) is also shown, with error bars indicating standard deviation.
In all specimens, positive pressure was noted after all sponges were inserted (Figure 4). The positive pressure ranged from 8 to 19.5 mm Hg, with a mean of 12.28 mm Hg. Comparisons between the specimens were performed using a Kruskal–Wallis one-way analysis of variance for unpaired samples. There were no significant differences in the average pressure among the 5 specimens (P=.235).
Bar graph showing the average pressure recorded at each pelvic site. For each specimen, the average pressure (regardless of the number of sponges) is shown for each of the 4 pelvic sensors, which measured pelvic floor pressure (♦), anterior pelvic brim pressure (■), middle pelvic brim pressure (▲), and posterior pelvic brim pressure (×). The mean pressure across all sensors (○) is also shown, with error bars indicating standard deviation.
This study investigated whether retroperitoneal pelvic packing provided enough pressure to control venous bleeding. The results show that the peak pressure generated when 3 sponges were packed, according to the original method described for pelvic packing, was greater than the central venous pressure.16 Moreover, the authors noted that the addition of each sponge induced an increase in the packing pressures at the sacroiliac joint and pelvic floor.
Previous studies have described the pressure-volume characteristics of the retroperitoneal space.17,18 However, the characteristics in the context of packing pressure were not reported in these studies. In addition, no clinical studies have reported on pelvic packing pressure because it is difficult to measure this pressure in medical practice. Several single-center clinical studies have reported that a therapeutic strategy comprising a combination of retroperitoneal pelvic packing, angiography, and external fixation is effective for the control of massive bleeding in pelvic fractures.8–12 Because the current authors performed a cadaveric study, not a clinical study, they were able to evaluate the effect of retroperitoneal pelvic packing alone.
The results showed that retroperitoneal pelvic packing for anatomically intact structures generated at least 6 mm Hg (8 cm H2O), which is almost the same as the central venous pressure.16 The current authors studied the effect of inserting up to 3 sponges because, in the original method, 3 surgical pads were packed into 1 side of the pelvic space,7 and the authors' preliminary assessment (data not shown) had suggested that inserting 4 sponges did not achieve higher pressure. Furthermore, the authors noted that packing pressures were more significant at the pelvic floor and posterior pelvic brim, which, compared with the other 2 points investigated (the anterior and middle pelvic brim), are more common bleeding points in pelvic fractures due to the proximity to the venous plexus. The authors found that the pressure at the anterior pelvic brim increased with the addition of just 1 sponge, possibly because the pressure of the soft tissue itself against the pelvic wall may have been induced with the insertion of the first sponge in the back. Overall, the authors' results showed that inserting 3 surgical sponges creates the optimal condition of packing pressure.
The current study had several limitations. First, cadaver specimens lack a cardiovascular reaction and muscle tone. The second limitation is the absence of pelvic fractures and bleeding in the authors' specimens; however, it should be noted that bleeding is expected to support the effect of pelvic packing with increasing retroperitoneal pressure. A previous study has demonstrated that saline infusion into the retroperitoneal pelvic space of the intact cadaveric pelvis increases pelvic pressure.18 It is expected that the bleeding-induced increase in hydrostatic pressure in the retroperitoneal space leads to more positive pressure on the pelvic wall and injured site. Therefore, the authors' conclusion that pelvic packing alone can overcome venous pressure would only be emphasized by including the aspect of bleeding because bleeding in a closed space reinforces the packing pressure rather than counteracting it. On the other hand, it was also demonstrated that retroperitoneal pelvic pressure significantly decreases after pelvic ring disruption.17,18 The current study did not clarify the effect of pelvic packing in the presence of pelvic ring disruption. A third limitation is related to the fact that all data were collected using a limited sample, consisting of 5 Japanese cadavers. The final limitation refers to the pressure measurement. Specifically, there were gaps between the sensors, thus not all pressure created by the surgical sponges could be accounted for, which is likely related to the variation observed in the values recorded by each sensor.
The latest report from the proponents of retroperitoneal pelvic packing provides important insight regarding the usefulness of pelvic packing in the clinical setting. Specifically, in analyzing the outcomes of the combination of pelvic packing and external fixation in 128 (6%) of 2293 patients with pelvic fracture treated during the course of 11 years, mortality was reported at 21%,19 which is lower than the mortality rate mentioned in the AAST report (32%)15 and other previous studies (40% to 60%).2–4 In the 128 patients reviewed by the proponents of pelvic packing, the major cause of death was not exsanguination or infection, but rather traumatic brain injury (33%), although the infection rate was especially high in patients requiring the repacking (45% vs 12% overall).19 The AAST trial indicated that, of the 178 patients with pelvic bone fracture and hemorrhagic shock, 10 (8.5%) patients were treated using retroperitoneal pelvic packing, 6 (5.1%) of whom were treated using pelvic packing alone.15
Based on the results of the latest clinical studies, it was estimated that less than 10% of patients with hemodynamically unstable pelvic fracture require retroperitoneal pelvic packing. The indication for pelvic packing depends strongly on the specific situation of each facility, which affects the availability of the interventional radiology team, interventional radiology room, orthopedic surgeon, trauma surgeon, and operating room. For this reason, the ideal clinical setting is not clearly defined, as has been noted in previous studies.11,12
At minimum, peritoneal pelvic packing with external fixation has been proven to be effective in reducing bleeding-related mortality in patients treated at facilities that do not provide 24-hour interventional radiology services.12 In fact, compared with angioembolization, peritoneal pelvic packing did not improve mortality rates significantly, although it should be noted that the time necessary for completing retroperitoneal pelvic packing is shorter than that required for performing angioembolization.9,20,21 Overall, angioembolization and external fixation are well-established strategies and should be considered preferentially in the management of hemodynamically unstable patients with pelvic fracture. However, if such treatments are not available or if hemodynamic instability persists after these treatments have been applied, retroperitoneal pelvic packing should be considered. This strategy is also consistent with the most recent guidelines proposed for the management of pelvic trauma.22 Indeed, the results the current authors obtained in the current cadaveric study suggest that retroperitoneal pelvic packing is a procedure worth implementing as a life-saving strategy if hemorrhagic shock cannot be controlled in patients with pelvic bone fracture.
The authors measured the pressure achieved by retroperitoneal pelvic packing in a cadaver model and found that 3 surgical sponges were needed to exceed central venous pressure (6 mm Hg), suggesting that retroperitoneal pelvic packing alone can be effective in the control of venous hemorrhage in pelvic fractures.
- Sathy AK, Starr AJ, Smith WR, et al. The effect of pelvic fracture on mortality after trauma: an analysis of 63,000 trauma patients. J Bone Joint Surg Am. 2009; 91(12):2803–2810. doi:10.2106/JBJS.H.00598 [CrossRef]
- Demetriades D, Karaiskakis M, Toutouzas K, Alo K, Velmahos G, Chan L. Pelvic fractures: epidemiology and predictors of associated abdominal injuries and outcomes. J Am Coll Surg. 2002; 195(1):1–10. doi:10.1016/S1072-7515(02)01197-3 [CrossRef]
- Parreira JG, Coimbra R, Rasslan S, Oliveira A, Fregoneze M, Mercadante M. The role of associated injuries on outcome of blunt trauma patients sustaining pelvic fractures. Injury. 2000; 31(9):677–682. doi:10.1016/S0020-1383(00)00074-7 [CrossRef]
- Starr AJ, Griffin DR, Reinert CM, et al. Pelvic ring disruptions: prediction of associated injuries, transfusion requirement, pelvic arteriography, complications, and mortality. J Orthop Trauma. 2002; 16(8):553–561. doi:10.1097/00005131-200209000-00003 [CrossRef]
- Huittinen VM, Slatis P. Postmortem angiography and dissection of the hypogastric artery in pelvic fractures. Surgery. 1973; 73(3):454–462.
- Ertel W, Keel M, Eid K, Platz A, Trentz O. Control of severe hemorrhage using C-clamp and pelvic packing in multiply injured patients with pelvic ring disruption. J Orthop Trauma. 2001; 15(7):468–474. doi:10.1097/00005131-200109000-00002 [CrossRef]
- Smith WR, Moore EE, Osborn P, et al. Retroperitoneal packing as a resuscitation technique for hemodynamically unstable patients with pelvic fractures: report of two representative cases and a description of technique. J Trauma. 2005; 59(6):1510–1514. doi:10.1097/01.ta.0000197330.81352.94 [CrossRef]
- Cothren CC, Osborn PM, Moore EE, Morgan SJ, Johnson JL, Smith WR. Preperitoneal pelvic packing for hemodynamically unstable pelvic fractures: a paradigm shift. J Trauma. 2007; 62(4):834–842. doi:10.1097/TA.0b013e31803c7632 [CrossRef]
- Osborn PM, Smith WR, Moore EE, et al. Direct retroperitoneal pelvic packing versus pelvic angiography: a comparison of two management protocols for haemodynamically unstable pelvic fractures. Injury. 2009; 40:54–60. doi:10.1016/j.injury.2008.08.038 [CrossRef]
- Hauschild O, Strohm PC, Culemann U, et al. Mortality in patients with pelvic fractures: results from the German pelvic injury register. J Trauma. 2008; 64(2):449–455. doi:10.1097/TA.0b013e31815982b1 [CrossRef]
- Tosounidis TI, Giannoudis PV. Pelvic fractures presenting with haemodynamic instability: treatment options and outcomes. Surgeon. 2013; 11(6):344–351. doi:10.1016/j.surge.2013.07.004 [CrossRef]
- Burlew CC, Moore EE, Smith WR, et al. Preperitoneal pelvic packing/external fixation with secondary angioembolization: optimal care for life-threatening hemorrhage from unstable pelvic fractures. J Am Coll Surg. 2011; 212(4):628–635. doi:10.1016/j.jamcollsurg.2010.12.020 [CrossRef]
- Cullinane DC, Schiller HJ, Zielinski MD, et al. Eastern Association for the Surgery of Trauma practice management guidelines for hemorrhage in pelvic fracture: update and systematic review. J Trauma. 2011; 71(6):1850–1868.
- Rossaint R, Bouillon B, Cerny V, et al. The European guideline on management of major bleeding and coagulopathy following trauma: fourth edition. Crit Care. 2016; 12:20–100.
- Costantini TW, Coimbra R, Holcomb JB, et al. Current management of hemorrhage from severe pelvic fractures: results of an American Association for the Surgery of Trauma multi-institutional trial. J Trauma Acute Care Surg. 2016; 80(5):717–723. doi:10.1097/TA.0000000000001034 [CrossRef]
- Debrunner F, Bühler F. “Normal central venous pressure”: significance of reference point and normal range. Br Med J. 1969; 3(5663):148–150. doi:10.1136/bmj.3.5663.148 [CrossRef]
- Grimm MR, Vrahas MS, Thomas KA. Pressure-volume characteristics of the intact and disrupted pelvic retroperitoneum. J Trauma. 1998; 44(3):454–459. doi:10.1097/00005373-199803000-00006 [CrossRef]
- Kohler D, Sellei RM, Sop A, et al. Effects of pelvic volume changes on retroperitoneal and intra-abdominal pressure in the injured pelvic ring: a cadaveric model. J Trauma. 2011; 71(3):585–590. doi:10.1097/TA.0b013e318224cd62 [CrossRef]
- Burlew CC, Moore EE, Stahel PF, et al. Preperitoneal pelvic packing reduces mortality in patients with life-threatening hemorrhage due to unstable pelvic fractures. J Trauma Acute Care Surg. 2017; 82(2):233–242. doi:10.1097/TA.0000000000001324 [CrossRef]
- Li Q, Dong J, Yang Y, et al. Retroperitoneal packing or angioembolization for haemorrhage control of pelvic fractures: quasi-randomized clinical trial of 56 haemodynamically unstable patients with Injury Severity Score ≥33. Injury. 2016; 47:395–401. doi:10.1016/j.injury.2015.10.008 [CrossRef]
- Jang JY, Shim H, Jung PY, Kim S, Bae KS. Preperitoneal pelvic packing in patients with hemodynamic instability due to severe pelvic fracture: early experience in a Korean trauma center. Scand J Trauma Resusc Emerg Med. 2016; 24:3. doi:10.1186/s13049-016-0196-5 [CrossRef]
- Coccolini F, Stahel PF, Montori G, et al. Pelvic trauma: WSES classification and guidelines. World J Emerg Surg. 2017; 12:5. doi:10.1186/s13017-017-0117-6 [CrossRef]