Blood Loss in Orthognathic Surgery: A Systematic Review

J Oral Maxillofac Surg 69:885-892, 2011

Blood Loss in Orthognathic Surgery: A Systematic Review Alejandra Piñeiro-Aguilar, DDS,* Manuel Somoza-Martín, DDS, PhD,† José M. Gandara-Rey, MD, DDS, PhD,‡ and Abel García-García, MD, PhD§ Purpose: Intraoperative blood loss during orthognathic surgery is frequently abundant and sometimes

requires blood transfusion. The aim of the present study was to conduct a systematic review of the published data regarding intraoperative blood loss during orthognathic surgical interventions, including Le Fort I osteotomy, mandibular ramus osteotomy, and both combined, to determine the range of information available to help surgeons better prepare themselves, their patients, and the auxiliary support needed for this type of surgery and the transfusion requirements. Materials and Methods: Selected reports from the PubMed and Cochrane Library databases for studies conducted from 1978 to 2008 were evaluated to determine whether they included information on the volume of bleeding during surgery and the factors that might have influenced the amount of bleeding. Of the 90 reports examined and evaluated, 7 were included in the critical analysis conducted as a part of the present systematic review. Results: Referring to the reports used for statistical analysis of the volume of blood loss, the mean intraoperative bleeding volume was 436.11 mL, the mean of the standard deviations was ⫾207.89 mL, and mean surgery duration was 196.9 minutes. Conclusions: Our results have shown that the intraoperative bleeding observed in patients during Le Fort I or mandibular ramus osteotomies or both combined was less than the limits set for blood transfusion. However, bleeding was occasionally heavier, and surgeons should be prepared for heavier bleeding by reserving blood at a blood bank or by preparing an autotransfusion. © 2011 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 69:885-892, 2011

Orthognathic surgery involves surgical manipulation of the facial skeletal elements to restore the anatomic and functional relationships in patients with dentofacial skeletal abnormalities. Many types of osteotomy of the jaw have been described for this purpose; however, in the present review, we have referred to the Le Fort I osteotomy of the upper jaw and mandibular ramus osteotomy, the most frequently performed osteotomies. The intraoperative blood loss during these operations is frequently abundant and sometimes requires a

blood transfusion. Awareness of the possible amount of blood loss during a given intervention is very helpful for clinicians when planning surgery. Accordingly, we conducted a systematic review of the published data regarding intraoperative blood loss during Le Fort I osteotomies, mandibular ramus osteotomies, and both combined. The goal of our study was to determine the range of information available to help surgeons better prepare themselves, their patients, and the auxil-

*Predoctoral Researcher, Department of Oral and Maxillofacial Surgery, Faculty of Medicine and Dentistry, University of Santiago de Compostela, Spain. †Assistant Professor, Department of Oral and Maxillofacial Surgery, Faculty of Medicine and Dentistry, University of Santiago de Compostela, Spain. ‡Oral Medicine Professor, Department of Oral and Maxillofacial Surgery, Faculty of Medicine and Dentistry, University of Santiago de Compostela, Spain. §Oral and Maxillofacial Surgery Professor, Department of Oral and Maxillofacial Surgery, Faculty of Medicine and Dentistry, Uni-

versity of Santiago de Compostela and University Hospital of Santiago de Compostela, Spain. Address correspondence and reprint requests to Dr García-García: Department of Maxillofacial Surgery, University of Santiago de Compostela Facultad de Medicina y Odontologia, C/Entrerríos S/n, Santiago de Compostela 15782, Spain; e-mail: [email protected] © 2011 American Association of Oral and Maxillofacial Surgeons

0278-2391/11/6903-0036$36.00/0 doi:10.1016/j.joms.2010.07.019

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BLOOD LOSS IN ORTHOGNATHIC SURGERY SELECTION CRITERIA

FIGURE 1. Flow diagram of the selection data process. Piñeiro-Aguilar et al. Blood Loss in Orthognathic Surgery. J Oral Maxillofac Surg 2011.

iary support for orthognathic surgery and transfusion requirements.

Materials and Methods LITERATURE SEARCH STRATEGIES

The PubMed and Cochrane Library databases were searched for studies published from 1978 to 2008 using the keywords “bleeding volume,” “orthognathic surgery,” and “blood loss.” Other references cited in the retrieved reports were also reviewed, and, if relevant, were included in our study. The studies considered relevant to our review were thoroughly examined, and a set of criteria were applied for their selection and inclusion in this systematic review (Fig 1). The abstracts and full texts were read and classified to select only those that provided the information necessary for our review. They were also sorted according to the potential risk of any type of bias.

Table 1 lists the 3 groups in which the reports were classified according to the information they provided. To perform an assessment and classification of the 3 groups described, the studies were selected according to the inclusion and exclusion criteria. The inclusion criteria were English-language reports and randomized clinical trials (RCT), reviews of RCTs, case series, cohort studies, and expert opinions in regard to bleeding during orthognathic surgery. The exclusion criteria were studies that had not collected or quantified information on blood loss during surgery and studies of patients with clotting problems, or with diseases that can affect bleeding. CRITICAL APPRAISAL

The selected articles were critically evaluated according to the following characteristics: inclusion/ exclusion criteria; information on the volume of bleeding during surgery; description of the surgical technique; information on the duration of surgery; information on the type of anesthesia used (normotensive or hypotensive); and information on the techniques, drugs, and materials used to reduce or increase bleeding or promote clotting. The selected studies were evaluated and catalogued to determine whether they were valid for inclusion in the present systematic review. We also accounted for information on the volume of bleeding during surgery and information on factors that might have influenced the amount of bleeding (Table 2). STATISTICAL ANALYSIS

For the data collected from the studies classified in group 1, we determined the mean value of the mean and standard deviation provided for surgical blood loss and surgery duration.

Table 1. CLASSIFICATION OF STUDIES IN 3 GROUPS ACCORDING TO TYPE AND SELECTION CRITERIA REFERRING TO BLEEDING PARAMETERS

Study Type

Group

Selection Criteria

Systematic review of RCTs Individual RCTs Case series Systematic review of cohort studies Individual cohort studies (including poor-quality RCTs) Result studies Systematic review of case and control studies Individual case-control studies Case series and poor quality cohort and case-control studies

1

Four bleeding parameters well described and defined and data on mean intraoperative blood loss volume collected

2

Expert opinion without explicit critical appraisal or based on physiology, bench research, or first principles

3

Four bleeding parameters well described and defined and intraoperative blood loss mentioned; data on mean intraoperative blood loss volume might or might not have been collected Opinions on factors influencing bleeding volume or studies on this subject

Abbreviation: RCT, randomized controlled trial. Piñeiro-Aguilar et al. Blood Loss in Orthognathic Surgery. J Oral Maxillofac Surg 2011.

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Table 2. INTRAOPERATIVE BLEEDING VOLUME PARAMETERS

Description of type of surgery Collection of data on intraoperative bleeding volume during surgery Description of anesthetic technique (normotensive or hypotensive) Duration of the intervention Description of drugs modifying bleeding volume Piñeiro-Aguilar et al. Blood Loss in Orthognathic Surgery. J Oral Maxillofac Surg 2011.

Results

EXCLUDED STUDIES TO CALCULATE THE MEAN BLOOD LOSS

The study by Stewart et al15 and the control group from the study by Praveen et al4 were excluded to calculate the mean blood loss. In the study by Stewart et al,15 the administration of heparin could have skewed the results about bleeding volume. In the second study, the patients had received normotensive anesthesia, which does not contribute to control bleeding. However, the treatment group from the study by Praveen et al4 was included. In the treatment group, the type of anesthesia used was the same as in the other reported studies used to calculate these data (Table 5).

INCLUDED STUDIES

A total of 90 studies were retrieved, 87 from PubMed1-87 and 3 from the Cochrane Library.88-90 These 90 reports were examined and evaluated comprehensively (by reading the full text, including the abstract); 17 articles1-17 were selected as meeting the criteria of our systematic review: 15 clinical studies1-12,15-17 of RCTs, case report series, or reviews of RCTs and 2 expert opinions.13,14 After the critical assessment, 7 were included in group 11,3-5,7,8,15 and 8 in group 2,2,6,9-12,16,17 with the 2 expert opinions in group 313,14 (Table 3). Accordingly, the 7 reports classified as group 11,3-5,7,8,15 were those that provided the most relevant information for the present systematic review (Table 4).

STATISTICAL ANALYSIS

The mean intraoperative blood loss volume was 436.11 mL. The mean of the standard deviations was ⫾207.89 mL.1,3-5,7,8 The mean surgery duration was 196.9 minutes.1,3-5,7,8,15 The mean of all surgery duration mean values (both treatment and control groups) for the studies was 185 minutes.1,3-5,7,8,15

Discussion Systematic reviews are an effective scientific approach to identifying and summarizing intervention evidence and its effectiveness, enabling consistency to be determined and the generalization of findings for the benefit of scientists. A critical assessment of

Table 3. STUDIES MEETING STUDY CRITERIA (N ⴝ 17) AND POTENTIAL BIAS

Investigator

Year

Kretschmer et al9

2008

Modig et al3 Kok-Leng Yeow et al10

2008 2008

Choi et al6 de Lange et al7 Paul et al11

2008 2008 2007

Kim et al2

2007

Chow et al12 Shepherd et al13 Kurian14 Zellin et al8 Stewart et al15 Panula et al1 Praveen et al4 Yu et al5 Samman et al16 Moenning et al17

2007 2007 2004 2004 2001 2001 2001 2000 1996 1995

Potential Bias Did not specify lost blood volume Did not describe method of randomization Nil Did not define exclusion criteria Did not mention intervention duration or anesthesia Did not specify lost blood volume Nil Included nonorthognathic surgery Did not specify intervention duration Did not specify lost blood volume Did not mention intervention duration or anesthesia Did not mention bleeding as surgery complication Did not mention intervention duration or anesthesia Expert opinion Expert opinion Nil Did not mention intervention duration Did not describe the anesthetic drugs used Did not mention intervention duration Nil Did not mention intervention duration or anesthesia Did not mention intervention duration Did not define exclusion criteria

Piñeiro-Aguilar et al. Blood Loss in Orthognathic Surgery. J Oral Maxillofac Surg 2011.

Group 2 1 2 type 1 1 2 2 type 2 type

type

3 3 1 1 1 1 1 2 2

888

Table 4. GROUP 1 STUDIES (N ⴝ 7): SUMMARY DATA Year

Sample Size

Intervention Duration (min)

Blood Loss Volume (mL)

Modig et al3

2008

—

ND

Hypotensive

212 (55-495)

266 (25-1,560)

de Lange et al7

2008

30 Treatment (n ⫽ 15) Control (n ⫽ 15)

Le Fort I

Hypotensive

Treatment: 91 (55-115) Control: 105 (60-150)

Treatment: 144 (75-275) Control: 346 (100-700)

Cocaine (100 mg) administered nasally to treatment group Adrenaline

Zellin et al8

2004

30 Treatment (n ⫽ 15) Control (n ⫽ 15)

Le Fort I

Hypotensive

Treatment: 227.5 (140-280) Control: 236.3 (130-310)

Treatment: 397.7 (150-800) Control: 736.7 (2001,400)

Treatment group managed with bleeding depressants (tranexamic acid 1 g intravenous or desmopressin 0.3 ␮g/kg)

Stewart et al15

2001

30 Treatment (n ⫽ 15) Control (n ⫽ 14)

Le Fort I BSSO GP Graft

Normotensive

Treatment: 473 ⫾ 150 Control: 986 ⫾ 356

Administration of aprotinin on the treatment group Administration of sodic heparin (5,000 U at 1 h before surgery)

Panula et al1

2001

655

Le Fort I BSSO

Hypotensive

Praveen et al4

2001

Le Fort I BSSO

Treatment: hypotensive Control: normotensive

Yu et al5

2000

53 Treatment (n ⫽ 24) Control (n ⫽ 29) 29

Le Fort I BSSO SARPE GP

Hypotensive

Surgery

—

Bleeding/Clotting Control

Results

Administration of tranexamic acid (100 mg/mL) or desmopressin Local anesthesia with adrenaline

No transfusions required No variation in bleeding rate according to gender No excessive intraoperative bleeding Only some hematomas observed as complications No relationship between age and bleeding volume Significant differences in volume lost between groups No considerable differences in surgery duration between groups No secondary effects caused by drugs used Transfusion required for 2 patients in control group No transfusion required for treatment group Significant differences in volume lost between groups Transfusion required for 1 patient in treatment group Transfusion required for 9 in control group 52% reduction in average bleeding volume in treatment group No secondary effects caused by drugs used Considerable bleeding in 6 patients One BSSO intervention canceled because of excessive bleeding Most significant blood loss during bimaxillary surgery followed by Le Fort I surgery Significant differences in volume lost between groups

162.2 (40-450)

451

—

—

Treatment: 200 (90-400) Control: 350 (150-1,575)

Administration of nitroglycerin and esmolol to treatment group

269 ⫾ 77.6

617 ⫾ 438.9

—

Bleeding reduced by 40% with hypotensive anesthesia Transfusion required for 1 patient Longest interventions were combined procedures Most significant blood loss occurred in combined procedures Relationship found between surgery duration and blood loss volume

Abbreviation: ND, not described; BSSO, bilateral sagittal split osteotomy; GP, genioplasty; SARPE, surgically assisted rapid palatal expansion genioplasty. Piñeiro-Aguilar et al. Blood Loss in Orthognathic Surgery. J Oral Maxillofac Surg 2011.

BLOOD LOSS IN ORTHOGNATHIC SURGERY

Anesthesia Type

Investigator

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Table 5. FACTORS INFLUENCING INTRAOPERATIVE BLEEDING VOLUME

Factor

Result

Duration of intervention Anticoagulant drugs

Increased bleeding volume

Hypotensive anesthesia Local vasoconstrictors

Reduced bleeding volume

Piñeiro-Aguilar et al. Blood Loss in Orthognathic Surgery. J Oral Maxillofac Surg 2011.

studies is one method of exploring any potential inconsistencies that might occur. The blood loss during orthognathic surgery can be considerable. The mean volume of intraoperative bleeding was 436.11 mL for the studies included in our review. The reason for the extensive blood loss is the extensive vascularization of the maxillofacial region and access difficulty in terms of cauterization or ligation of the vessels involved. This bleeding is caused by the palatal large vessels (sphenopalatine artery and descending palatine artery), the pterygoid plexus, and the internal maxillary artery and its collateral branches to the upper jaw in Le Fort I osteotomies. The maxillary artery and its branches are the most vulnerable to injury during pterygomaxillary dysjunction or maxillary down fracture, specifically, the descending palatine artery. It can also be damaged if the maxilla is advanced to a significant degree, intruded posteriorly, or retruded. In the case of the mandible, the bleeding occurs from the alveolar arteries and the facial artery or branches of these. In concrete with bilateral sagittal split osteotomy, hemorrhage results from laceration of the maxillary artery. However, this is unlikely to occur when the soft tissues are reflected properly and when appropriate precautions are taken with retractors to protect the vessels. Bimaxillary surgery results in a major volume of blood loss directly related to the operating time and the magnitude of the intervention.5 Blood transfusion is an expensive procedure that can also lead to complications, such as the transmission of disease or graft versus host reactions. Transfusions should be avoided, if possible, by taking steps to reduce bleeding that does not ultimately cause harm to the patient. It seems to be well established that a directly proportional relationship exists between the duration of the intervention and the bleeding volume. The operative time and blood loss are greater for bimaxillary surgery than for surgery affecting only the upper jaw or the mandible.

BLOOD LOSS REDUCTION

Controlling intraoperative bleeding to prevent excessive blood loss requires a good view of the surgical field, a good knowledge of anatomy, and the exercise of care during the intervention.15 Bleeding can be minimized by respecting the margins for the various vessels in the surgical field. The surgeon’s skill is particularly important in terms of compressing the area with gauze and/or cauterizing or ligating the vessels responsible for bleeding. To reduce bleeding, locally applied drugs, such as tranexamic acid, desmopressin, adrenaline, and so forth, can be used.2,8 de Lange et al7 found noticeable differences between the control and treatment groups that had received nasally applied cocaine (a gauze strip with 100-mg cocaine and 2 mL 1:100,000 adrenaline) without side effects. This drug has been used during nasal surgery to reduce blood loss and enhance visibility, and it can be combined with adrenaline for an increased vasoconstrictor effect without increasing the cardiovascular complications. Cocaine causes vasoconstriction by blocking the reuptake of noradrenaline and adrenaline at the sympathetic nerve endings. The simultaneous use of adrenaline allows a high concentration of local catecholamines to be reached. Cocaine must be used with propanolol as a general anesthetic to reduce the risk of arrhythmia, and its use should be avoided in children because of their lower tolerance to this drug.7 Other investigators15 have used bleeding depressants, such as intravenous aprotinin (50 mL/hour during the intervention), a protease that can, however, cause hypersensitivity reactions.14 Aprotinin acts on plasmin, trypsin, and kallikrein and has been used in cardiac surgery as an inhibitor of fibrinolysis and to preserve platelet function. It has also been used to reduce blood loss during procedures, such as hip replacement, urologic surgery, liver transplantation, and aortoiliac surgery without the risk of thrombosis.15 Stewart et al15 found a quite high incidence of bleeding in 2 study groups, especially in the group that had received bleeding depressants. One possible reason was the administration of heparin to all patients 1 hour before the intervention. It is noteworthy that none of the studies considered the complications that can result from the use of drugs to control bleeding. Zellin et al8 found that bleeding was reduced with intravenously administered bleeding depressants, such as desmopressin (0.3 ␮g/kg) and tranexamic acid (1 g). Modig et al3 found no excessive bleeding after intravenously administering tranexamic acid or desmopressin. Tranexamic acid has been used to reduce blood loss and the subsequent need for transfusion in orthopedic, spinal, and cardiac surgery. Tranexamic acid is

890 a synthetic derivative of the amino acid lysine. Its antifibrinolytic effects are caused by the reversible blockade of lysine-binding sites on plasminogen molecules. It has also been used in dentistry and oral surgery as a mouthwash for patients with anticoagulation or hemorrhagic problems. Different dosages have been reported, ranging from a bolus administration of 1 g to 100 mg/kg within 15 minutes and continued with an infusion of 10 mg/kg/ hour until wound closure. This drug does not have any significant adverse effects.3,8 Desmopressin acetate is an analog of the hormone vasopressin. It has been shown to increase the plasma concentration of endothelial factor VII, increasing coagulant activity; however, its role as a hemostatic agent during surgery is doubtful.8 Despite these data, however, insufficient evidence is available in favor of using these drugs to reduce the number of transfusions. Two patients in the study by Zellin et al8 required blood transfusions; 6 patients in the study by Panula et al1 bled excessively, with the consequent necessity of suspending one of the interventions; and 1 patient in the study by Stewart et al15 and by Yu et al5 required a transfusion. Another method to reduce operative bleeding is to induce controlled hypotension during surgery.1,3-5,7,12,13 Making a comparative analysis between the variables in each of the studies, we observed that hypotensive anesthetic techniques were used in most to intentionally reduce the blood pressure to 55 to 80 mm Hg in normotensive patients. The safety margin for blood pressure in patients with American Society of Anesthesiologists Class I is a mean arterial pressure of 55 mm Hg or greater or a systolic blood pressure of 80 mm Hg or greater. However, monitoring during intervention of patients undergoing hypotensive anesthesia is still essential (electrocardiography, arterial oxygen saturation, temperature, measurement of arterial pressure, end tidal carbon dioxide tension, and urine output). This technique is also indicated for any patient, including children, and in different surgical procedures. For some investigators, the anesthetic technique has enabled a good control of blood loss in most patients and its benefits are greater than the potential risks.5,6 Moreover, hypotensive anesthesia is indicated for lengthy procedures in which a large amount of blood loss and consequent transfusion are expected, such as bimaxillary osteotomies.6 Praveen et al4 compared normotensive and hypotensive anesthesia and reported significant differences between the 2 groups. In the hypotensive group, the average blood loss was 200 mL (maximum 400) compared with 350 mL (maximum 1,575 mL) in the normotensive group. Zellin et al,8 however, reported an average of 736.7 mL blood loss during Le

BLOOD LOSS IN ORTHOGNATHIC SURGERY

Fort I surgery conducted using hypotensive anesthesia. Thus, contradictory results have been reported by different investigators. The question remains to what extent the intraoperative blood loss in orthognathic surgery is significant. The effect of the loss of red blood cells on the hemodynamics and the development of anemia will depend on the total blood volume of the patient, which, in turn, is related to the patient’s weight. The lower the patient’s weight, the greater the effect of intraoperative blood loss on hemodynamics and anemia development. Investigators such as Nath and Pogrel31 concluded that the transfusion needs for most oral and maxillofacial surgery have been overestimated. They also reported that the option of autologous transfusions cost more than homologous. From our review, we have concluded that intraoperative bleeding observed in patients undergoing Le Fort I and mandibular ramus osteotomies, alone or combined, has generally been less than the limits set to determine the need for a blood transfusion (indicated in healthy adults when the hemoglobin is less than 7 g/dL). However, bleeding can sometimes reach or surpass the threshold limits for a blood transfusion, and this event should be anticipated by reserving blood at a blood bank or by preparing an autotransfusion.16,17,26,31,34,37,41,51

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