The influence of blood on the efficacy of intraperitoneally applied phospholipids for prevention of adhesions
© Butz et al; licensee BioMed Central Ltd. 2007
Received: 24 February 2007
Accepted: 25 July 2007
Published: 25 July 2007
The formation of adhesions following abdominal surgery is a well known problem. In previous studies we demonstrated the efficacy and safety of intraperitoneally applied phospholipids in order to prevent adhesion formation. This study evaluates the influence of blood on the efficacy of intraperitoneally applied phospholipids for prevention of adhesions.
In 40 Chinchilla rabbits adhesions were induced by median laparotomy, standardized abrasion of the visceral and parietal peritoneum in defined areas of the ventral abdominal wall and the caecum. The animals were randomly divided into four groups. They received either phospholipids 3.0% or normal saline (NaCl 0,9%) (5 ml/kg body weight). In 50% of the rabbits we simulated intraperitoneal bleeding by administration of blood (1,5 ml/kg body weight). The other half served as control group. Ten days following the operation the animals were sacrificed and adhesion formation was assessed by computer aided planimetry and histopathologic examination.
The median adhesion surface area in the NaCl-group (n = 9) amounted to 68,72 mm2, in the NaCl+Blood-group (n = 10) 147,68 mm2. In the Phospholipid (PhL)-group (n = 9) the median adhesion surface area measured 9,35 mm2, in the PhL+Blood-group (n = 9) 11,95 mm2. The phospholipid groups had a significantly smaller adhesion surface area (p < 0.05).
Again these results confirm the efficacy of phospholipids in the prevention of adhesions in comparison to NaCl (p = 0,04). We also demonstrated the adhesion preventing effect of phospholipids in the presence of intraperitoneal blood.
Postoperative peritoneal adhesions are frequent and serious sequelae after abdominal surgery. They cause recurrent and chronic complaints and pain as well as female infertility, and they increase the duration and complication rate of reoperations[1, 2]. The incidence of postoperative peritoneal adhesions and their related complications are constantly rising parallel to increasing longevity and growing numbers of surgical procedures[3, 4]. Today they are the most frequent cause of intestinal obstruction, account for 3% of all hospital admissions in general surgery, and are responsible for about 30% of all cases of female infertility. Intestinal obstruction as the most life threatening adhesion-related disease is associated with mortality rates of up to 15%[5, 6]. Adhesions as almost inevitable sequel after abdominal procedures are generating a rising clinical workload and need for substantial health care expenditures [7–12].
Peritoneal lesions caused by abrasion, ischaemia, desiccation, infection, thermal injury, and foreign bodies are the origin of adhesions. Especially the presence of blood is an initiating causepoint of adhesions. Traumatization leads to a deposition of fibrin and fibrinous, potentially temporary, adhesions. Postoperatively, however, tissue plasminogen activator (t-PA) activity is reduced and inflammatory cytokines (tumor necrosis factor (TNF), Interleukin-1 (IL-1), Interleukin-6 (IL-6)) as well as plasminogen activator inhibitors (PAI-1, PAI-2) are elevated. Due to the hereby decreased fibrinolytic activity in the peritoneal cavity, the fibrin depositions are infiltrated by granulocytes, monocytes, and fibroblasts followed by ingrowth of capillaries, deposition of collagen, and fibrous permanent adhesions.
The clinical consequences call for adjuvant means for prevention and control of peritoneal adhesions. A plethora of attempts have been made at prevention and control of postoperative adhesion formation. All efforts directed at the reduction of the surgical trauma by using laparoscopic access and meticulous preparation however, could not solve this problem[14, 15]. With the pathogenesis in mind, the idea to enhance the fibrinolytic activity by e.g. urokinase or recombinant tissue plasminogen activator (rtPA) was striking. But in the clinical routine the result would be a possible disturbance of the delicate balance between coagulation and fibrinolysis causing a postoperative bleeding hazard.
Non-steroidal anti-inflammatory drugs and corticosteroids carry the risk of haemorrhage, ulcers with subsequent bleeding, immunosuppression, and healing disorders. Saline solutions are too rapidly absorbed and hydrofloatation by macromolecular solutions like dextran show significant adverse effects like fluid shifting, impairment of liver function, even rare cases of dissiminated intravascular coagulation, and anaphylactic shock[15, 17].
Phospholipids are a surfactant-like substance with excellent release and lubricating properties that adsorb as an oligolamellar lining to the mesothelium. They offer the possibility to cover the whole surface of the visceral and parietal peritoneum by a small amount of fluid during healing of the serosal defects. By acting as a liquid barrier separating opposite areas of the peritoneum by a very thin membrane-like film they proved to reduce adhesion formation and reformation in different settings including general peritonitis[19, 20].
During operative procedures some degree of bleeding is inevitable. This small amount of blood can induce adhesions. Special barriers for prevention of adhesions in form of patches are ineffective in the presence of blood [29–31]. In this study we evaluate the efficacy of phospholipids in a bleeding model.
Animals and Anaesthesia
A total of 40 Chinchilla rabbits (mean body weight 2.9 ± 0.6 kg) were included in this study. The animals were kept in single cages under standard laboratory conditions with unrestricted access to a balanced pellet diet and water. After adaptation, the rabbits were randomly assigned to four different groups of equal numbers. The surgical procedures were performed under sterile conditions and general anaesthesia by i.v. administration of ketamine (Ketamin®10%, Sanofi-Ceva, Düsseldorf, Germany) and xylazine (Xylazin 2%Bernburg, medistar, Germany). The protocol was approved by the local Animal Use and Care committee and the experiments were conducted in accordance with the animal protection laws.
Induction of Adhesions
Via a midline incision, the caecum was exposed. The parietal and visceral peritoneum of the ventral abdominal wall and the caecum, respectively, were abraded within a total area of 9 cm2. For this purpose a stamp calibrated to a pressure of 4 kPa with an emery paper (260 grains per cm2) mounted to a curved plate was used.
NaCl + Blood
PhL + Blood
In the bleeding groups the blood was taken from a mesenterial vene in a dosage of 1.5 ml per kg body weight. The blood was dispersed in the abdominal cavity near to the abraded areas (described above). Then the midline incision was closed by a running suture 3-0 polyglycolic acid.
Prior to the last stitch of abdominal closure 5 ml per kg body weight of phospholipids (Fresenius, Germany) or 0.9% saline solution (NaCl, control group) were instilled into the abdominal cavity. The lipid emulsion consisted of purified egg derived phospholipids, stabilized by glycerol, adjusted to physiological pH by sodium hydroxide, and water for injection to achieve a concentration of 3.0% (30 g phospholipids per 1000 g of emulsion). The final product was supplied in sterile and pyrogene-free condition. Evaluation of all parameters was carried out in a blinded fashion.
Assessment of Adhesions
After 10 days (n = 37) the animals were sacrificed by a lethal dose of pentobarbital sodium (Narcoren®, Rhône Merieux, Laupheim, Germany). The abdomen was opened via a full left para-median incision for complete exploration. Peritoneal adhesions were meticulously dissected and the intestine was opened along the mesenteric attachment for computed planimetry.
Adhesion carrying tissues (bowel, abdominal wall, omentum) were excised en-bloc and fixed in formaldehyde solution. Sections with a thickness of 5 μm were stained with haematoxylin and eosin (HE) for light microscopy to evaluate the structure of the connective tissue and the healing process.
All data are expressed as median. The Mann-Whitney U test for independent samples was used for statistical analysis. P < 0.05 was considered statistically significant.
Performance of the initial surgical procedure was uneventful in all animals. Postoperatively three animals of three different groups died of pneumonia. Therefore the following data are based on the final examination of 37 animals.
The median (in mm2) of the adhesion area in the NaCl group (n = 9) was 68,72 and in the NaCl+blood group 147,68.
The adhesion area in the NaCl group is significantly higher compared to the PhL group (p = 0,04). Between the blood groups again the one with added NaCl showed a significantly higher adhesion area compared to the one with added PhL (p = 0,017). Consequently the adhesion area in the NaCl+blood group compared to the PhL group is also significantly higher (p = 0,004).
No statistically significant difference was seen between the two PhL groups (p = 0,863). (see Figure 1)
Histological analysis of representative specimens of the injured sites revealed an inflammatory-reparative tissue response with non-specific granulation tissue infiltrated by mono- and polymorphonuclear cells. Activated mesothelial cells were found on the serosal surface as well as subserosal fibroblastic proliferations. No differences of the histological and cellular patterns were observed between the control and the test groups.
During visceral surgery damage to the mesothelial lining is inevitable due to desiccation, thermal injury and surgical trauma. These lesions lead to oozing out of a fibrinous exsudate, a reduction of fibrinolytic acivity and subsequent adhesion formation [23–25].
The refinement of surgical technique, minimizing the peritoneal injury and avoidance of tissue ischaemia markedly reduce postsurgical adhesions, but do not dissolve them completely.
Phospholipids, polar phosphoric acid di-esters are the natural constituents of abdominal cavity fluid and cell membranes. Human mesothelial cells were found to rapidly synthesize and secrete this surfactant-like substance. Phospholipids are zwitterions with a positive charged quaternary ammonium ion that is able to bind to negative charges of epithelial surfaces . This fact enables small amounts of phospholipids to cover the whole surface of the visceral and parietal peritoneum during the healing process of serosal defects in the surgical setting.
In our study we investigated the influence of peritoneal bleeding on adhesion formation in the presence of phospholipids. Few data exist with regard to the latter.
Bioresorbable membranes like Seprafilm® or Interceed® showed in one study a reduced effectiveness in the prevention of adhesions in the presence of blood in the abdominal cavity.[29, 30] In the case of Interceed barrier (oxidized regenerated cellulose) the presence of blood abolished its effect on the prevention of coecal adhesions and all in all the effectiveness was reduced except in neutralized Interceed (nTC7).
For the hyaluronan derivative gel (auto-cross-linked polysaccharide (ACP) gel) in different preparations (20,40,60 mg/ml) De Iaco et al. demonstrated the effectiveness in postsurgical adhesion prevention even in the presence of blood. There were no differences between the phospholipid groups.
Our results are in line with our previous studies and confirm the efficacy of phospholipids in adhesion prevention compared to a control group (p = 0,04).
The mean adhesion area counts to 9,35 mm2 in PhL and 11,95 mm2 in the PhL+blood group. In addition the effectiveness of PhL in adhesion prevention was not reduced by the presence of intraabdominal blood.
Again, these findings demonstrate the significant capability of phospholipids to reduce adhesion formation. The presence of intraabdominal blood does not interfere with its efficacy.
This work was supported by a grant from Fresenius AG, Bad Homburg, Germany.
We thank Michael Polivoda, MD who contributed to acquisition of data.
We thank Gabriele Boehm, MD for copyediting the paper.
- Beck DE, Opelka FG, Bailey HR, Rauh SM, Pashos CL: Incidence of small-bowel obstruction and adhesiolysis after open colorectal and general surgery. Dis Colon Rectum. 1999, 42 (5): 241-248. 10.1007/BF02237135.View ArticlePubMed
- Van der Krabben AA, Dijkstra FR, Nieuwenhuijzen M, Reijnen MM, Schaapveld M, van Goor H: Morbidity and mortality of inadvertent enterotomy during adhesiotomy. Br J Surg. 2000, 87: 467-471. 10.1046/j.1365-2168.2000.01394.x.View ArticlePubMed
- Ellis H, Moran BJ, Thompson JN, Parker MC, Wilson MS, Menzies D, McGuire A, Lower AM, Hawthorn RJ, O'Brien F, Buchan S, Crowe AM: Adhesion-related hospital readmissions after abdominal and pelvic sugery: a retrospective cohort study. Lancet. 1999, 353: 1476-1480. 10.1016/S0140-6736(98)09337-4.View ArticlePubMed
- Treutner KH, Schumpelick V: Prevention of adhesions. Wish and reality. Chirurg. 2000, 71: 510-517. 10.1007/s001040050848.View ArticlePubMed
- Milamed DR, Hedley-White J: Contributions of the surgical sciences to a reduction of the mortality rate in the United States for the period 1968 to 1988. Ann Surg. 1994, 219: 94-102. 10.1097/00000658-199401000-00015.PubMed CentralView ArticlePubMed
- Wilson MS, Ellis H, Menzies D, Moran BJ, Parker MC, Thompson JN: A review of the management of small bowel obstruction. Members of the Surgical and Clincal Adhesions Research Study (SCAR). Annals of the Royal College of Surgeons of England. 1999, 81: 320-328.PubMed CentralPubMed
- DeLange DCD, Jeekel J: Prevalence of adhesions and the associated costs in general surgery. Peritoneal Surgery: 2000; New York. Edited by: diZerega GS. 2000, New York: Springer, 307-320.View Article
- Ellis H: The magnitude of adhesion-related problems. Peritoneal Surgery: 2000; New York. Edited by: diZerega GS. 2000, New York: Springer, 297-306.View Article
- Ivarsson ML, Holmdahl L, Franzen G, Risberg B: Cost of bowel obstruction resulting from adhesions. Eur J Surg. 1997, 163: 679-684.PubMed
- Moscowitz I, Wexner SD: Contributions of adhesions to the cost of healthcare. Peritoneal Surgery: 2000; New York. Edited by: diZerega GS. 2000, New York: Springer, 335-342.View Article
- Ray NF, Denton WG, Thamer M, Henderson SC, Perry S: Abdominal adhesiolysis: inpatient care and expenditures in the United States in 1994. J Am Coll Surg. 1998, 186: 1-9. 10.1016/S1072-7515(97)00127-0.View ArticlePubMed
- Ray NF, Larsen JW, Stillman RJ, Jacobs RJ: Economic impact of hospitalizations for lower abdominal adhesiolysis in the United States in 1988. Surg Gynecol Obstet. 1993, 176: 271-276.PubMed
- Thompson J: Pathogenesis and prevention of adhesion formation. Dig Surg. 1998, 15: 153-157. 10.1159/000018610.View ArticlePubMed
- Kowalczyk CL, Diamond MP: The management of adhesive disease. Peritoneal Adhesions: 1997; Berlin, Heidelberg, New York. Edited by: Treutner KH, Schumpelick V. 1997, New York: Springer, 315-324.View Article
- Wiseman DM: Adhesion prevention: past and future. Peritoneal Surgery: 2000; New York. Edited by: Gere S, di Zerega GS. 2000, New York: Springer, 401-417.View Article
- Hill-West JL, Dunn RC, Hubell JA: Local release of fibrinolytic agents for adhesion prevention. J Surg Res. 1995, 59: 759-763. 10.1006/jsre.1995.1236.View ArticlePubMed
- Shear L, Swartz C, Shinaberger JA, Barry KG: Kinetics of peritoneal fluid absorption in adult man. N Engl J Med. 1965, 272: 123-127.View ArticlePubMed
- Hills BA, Burke JR, Thomas K: Surfactant barrier lining peritoneal mesothelium: lubricant and release agent. Perit Dial Int. 1998, 18: 157-165.PubMed
- Ar'Rajab A, Ahren B, Rozga J, Bengmark S: Phosphatidylcholine prevents postoperative peritoneal adhesions: an experimental study in rat. J Surg Res. 1991, 50: 212-215.View ArticlePubMed
- Ar'Rajab A, Snoj M, Larsson K, Bengmark S: Exogenous phospholipid reduces postoperative peritoneal adhesion in rats. Eur J Surg. 1995, 161: 341-344.PubMed
- Müller SA, Treutner KH, Tietze L, Anurov M, Titkova S, Polivoda M, Oettinger AP, Schumpelick V: Efficacy of adhesion prevention and impact on wound healing of intraperitoneal phospholipids. J Surg Res. 2001, 96: 68-74. 10.1006/jsre.2000.6031.View ArticlePubMed
- Müller SA, Treutner KH, Tietze L, Anurov M, Titkova S, Polivoda M, Oettinger AP, Schumpelick V: Influence of intraperitoneal phospholipid dosage on adhesion formation and wound healing at different intervals after surgery. Langenbecks Arch Surg. 2001, 386: 278-284. 10.1007/s004230100212.View ArticlePubMed
- Ivarsson ML, Falk P, Holmdahl L: Response of visceral peritoneum to abdominal surgery. Br J Surg. 2001, 88: 148-151. 10.1046/j.1365-2168.2001.01630.x.View ArticlePubMed
- Scott-Coombes D, Whawell S, Vipond MN, Thompson J: Human intraperitoneal fibrinolytic response to elective surgery. Br J Surg. 1995, 82: 414-417. 10.1002/bjs.1800820346.View ArticlePubMed
- Thompson J, Whawell SA: Pathogenesis and prevention of adhesion formation. Br J Surg. 1995, 82: 3-5. 10.1002/bjs.1800820103.View ArticlePubMed
- Müller SA, Treutner KH, Jorn H, Anurov M, Oettinger AP, Schumpelick V: Phospholipids reduce adhesion formation in the rabbit uterine horn model. Fertil Steril. 2002, 77: 1269-1273. 10.1016/S0015-0282(02)03094-7.View ArticlePubMed
- Hills BA: Role of surfactant in peritoneal dialysis. Perit Dial Int. 2000, 20: 503-515.PubMed
- Hills BA: Graphite-like lubrication of mesothelium by oligolamellar pleural surfactant. J Appl Physiol. 1992, 73: 1034-1039.PubMed
- De Cherney AH, di Zerega GS: Clincal problem of intraperitoneal postsurgical adhesion formation following general surgery and the use of adhesion prevention barriers. Surg Clin North Am. 1997, 77 (3): 671-688. 10.1016/S0039-6109(05)70574-0.View Article
- Larsson B: Efficacy of Interceed in adhesion prevention in gynecologic sugery: a review of 13 clinical studies. J Reprod Med. 1996, 41: 27-34.PubMed
- Wiseman DM, Gottlick-Iarkowski L, Kamp L: Effect of different barriers of oxidized regenerated cellulose (ORC) on cecal and sidewall adhesions in the presence and absence of bleeding. J Invest Surg. 1999, 12: 141-146. 10.1080/089419399272539.View ArticlePubMed
- De Iaco PA, Muzzupapa G, Bigon E, Pressato D, Dona M, Pavesio A, Bovicelli L: Efficacy of a hyaluron derivative gel in postsurgical adhesion prevention in the presence of inadequate hemostasis. Surgery. 2001, 130 (1): 60-64. 10.1067/msy.2001.115102.View ArticlePubMed
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2482/7/14/prepub
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