Orthognathic surgery with or without induced hypotension

Systematic mapping review of orthognathic surgery

STUDY DESIGN

Systematic mapping review AIM AND SCOPE: The objective of this mapping review was to identify, describe, and organize clinical research currently available from systematic reviews and primary studies regarding co-interventions and different surgical modalities used in orthognathic surgery (OS) and their outcomes.

METHODS

Systematic reviews (SRs), randomized controlled trials, and observational studies that evaluated perioperative OS co-interventions and surgical modalities were identified in an exhaustive search of MEDLINE, EMBASE, Epistemonikos, Lilacs, Web of Science, and CENTRAL. Grey literature was also screened.

RESULTS

Included were 35 SRs and 253 primary studies, 103 from SRs, and another 150 identified in our search. Overall, SR quality was rated as critically low, with only two SRs rated as of high quality. 19 questions on population, interventions, comparisons, and outcomes (PICO) extracted from the SRs focused on osteosynthesis methods, surgical cutting devices, and use of antibiotics, corticosteroids, and induced hypotension. Also identified were 15 research gaps. Evidence bubble maps were created to graphically depict the available evidence.

CONCLUSION

Future high-quality research, both primary and secondary, is needed to address the knowledge gaps identified in this systematic mapping review.

Comparative Evaluation of Hypotensive and Normotensive Anesthesia on LeFort I Osteotomies: A Randomized, Double-Blind, Prospective Clinical Study

Introduction

Orthognathic surgery can account for a considerable amount of blood loss since the vascularization of maxillofacial region is such that major bleeding can occur. Intra-bony bleed is often involved as a major aspect of blood loss associated with osteotomies, especially LeFort I osteotomy when performed during orthognathic surgery. This study evolved as a result of the increasing concern to attain a clear surgical field and reduce the duration of surgical procedure and the amount of blood loss associated with orthognathic surgery with the use of controlled hypotension.

Method

Twenty patients planned for undergoing LeFort I osteotomy were randomly allocated into two groups (Group 1-normotensive anesthesia; Group 2-hypotensive anesthesia). The amount of blood loss, mean difference between hemoglobin and hematocrit in the preoperative and postoperative period, and quality of surgical field were evaluated for patients in the two groups.

Conclusion

Comparative analysis of the various parameters showed a statistically significant improvement in the hypotensive group when compared to normotensive group, although the duration of surgery and postoperative morbidity were not significantly affected when controlled hypotension was used.

Efficacy of minimal invasive cardiac output and ScVO2 monitoring during controlled hypotension for double-jaw surgery

Background

Controlled hypotension (CH) provides a better surgical environment and reduces operative time. However, there are some risks related to organ hypoperfusion. The EV1000/FloTrac system can provide continuous cardiac output monitoring without the insertion of pulmonary arterial catheter. The present study investigated the efficacy of this device in double jaw surgery under CH.

Methods

We retrospectively reviewed the medical records of patients who underwent double jaw surgery between 2010 and 2015. Patients were administered conventional general anesthesia with desflurane; CH was performed with remifentanil infusion and monitored with an invasive radial arterial pressure monitor or the EV1000/FloTrac system. We allocated the patients into two groups, namely an A-line group and an EV1000 group, according to the monitoring methods used, and the study variables were compared.

Results

Eighty-five patients were reviewed. The A-line group reported a higher number of failed CH (P = 0.005). A significant correlation was found between preoperative hemoglobin and intraoperative packed red blood cell transfusion (r = 0.525; P < 0.001). In the EV1000 group, the mean arterial pressure (MAP) was significantly lower 2 h after CH (P = 0.014), and the cardiac index significantly decreased 1 h after CH (P = 0.001) and 2 h after CH (P = 0.007). Moreover, venous oxygen saturation (ScVO₂) decreased significantly at both 1 h (P = 0.002) and 2 h after CH (P = 0.029); however, these values were within normal limits.

Conclusion

The EV1000 group reported a lower failure rate of CH than the A-line group. However, EV1000/FloTrac monitoring did not present with any specific advantage over the conventional arterial line monitoring when CH was performed with the same protocol and same mean blood pressure. Preoperative anemia treatment will be helpful to decrease intraoperative transfusion. Furthermore, ScVO₂ monitoring did not present with sufficient benefits over the risk and cost.

Efficacy and safety of diode laser during circumvestibular incision for Le Fort I osteotomy in orthognathic surgery: a triple-blind randomized clinical trial

The aim of this triple-blind randomized clinical trial was to evaluate the efficacy and safety of diode laser during circumvestibular incisions for Le Fort I osteotomy in orthognathic surgeries in comparison with conventional techniques using electrocautery and scalpel. Patients were randomly allocated to one of three groups based on the technique employed to perform incisions: diode laser, electrocautery, and scalpel. The parameters used to evaluate the efficacy and safety of diode laser were incision velocity, duration of surgery, bleeding rate, alterations in postoperative functions, pain, edema, wound clinical healing, and infection. Thirty patients were enrolled in the study (10 per group). Regarding bleeding, the incisions performed with diode laser promoted a lower bleeding rate compared with scalpel and electrocautery (p = 0.00). The diode surgical laser was effective during the incision procedure, but required a longer time to perform the incisions compared with the other techniques evaluated (p < 0.05). No statistically significant difference was detected between groups regarding total surgical time or other safety parameters (p > 0.05). Thus, diode laser proved to be effective and safer during circumvestibular incisions for Le Fort I osteotomy than conventional devices.

Controlled Hypotension During Rhinoplasty: A Comparison of Dexmedetomidine with Magnesium Sulfate

Objective

The current study aimed at comparing the efficacy of dexmedetomidine and magnesium sulfate to control blood pressure (BP) during rhinoplasty and the resultant effects on the quality of surgical field in terms of bleeding and visibility.

Methods

The current randomized, prospective, double-blind study was conducted on 60 patients aged 18 to 50 years classified as ASA (American Society of Anesthesiologists) physical status I who were candidates for rhinoplasty. Patients were randomly divided into 2 groups: (1) group Dex, received 1 µg/kg dexmedetomidine in 10 minutes before induction of anesthesia, followed by 0.4 - 0.6 µg/kg/hour during the maintenance of anesthesia, and (2) group Mg, received 40 mg/kg in 10 minutes before anesthesia induction followed by 10 - 15 mg/kg/hour during anesthesia maintenance. In both groups, the goal was to achieve a mean arterial pressure (MAP) of 60 - 70 mmHg. Hemodynamic variables, anesthetic, opioid, muscle relaxant requirements, and surgical field condition were recorded. Sedation score, time to reach modified Aldrete score ≥ 9, and adverse effects including nausea and vomiting (N&V) and shivering were recorded.

Results

Controlled hypotension was achieved in both groups. There was no significant difference in MAP between the groups, but heart rate (HR) was significantly lower in the Dex group (P < 0.001), compared with that of the Mg group. Bleeding score was lower (P < 0.001) and surgeon's satisfaction score was higher (P < 0.001) in the Dex group. More patients required fentanyl (P < 0.001) or nitroglycerin (P < 0.001) and the mean fentanyl (P = 0.005) or nitroglycerin (P < 0.001) required doses were higher in the Mg group. Patients in the Dex group required more frequent administration of cisatracurium (P = 0.004). Five patients in the Dex group versus no patients in the Mg group received atropine (P = 0.023). Ramsay sedation score and time to reach modified Aldrete score ≥ 9 were significantly higher in the Dex group (P < 0.001 and P < 0.001, respectively). The incidence rate of N&V and shivering were similar in both groups.

Conclusion

Dexmedetomidine was more effective than magnesium to achieve controlled hypotension, and provide a favorable surgical field condition. However, dexmedetomidine also heightened the risk of induced bradycardia and prolonged sedation. These are 2 important points to consider when applying this drug as a hypotensive agent during operation.

Quantitative analysis of facial soft tissue perfusion during hypotensive anesthesia using laser-assisted indocyanine green fluorescence angiography

The aim of this study was to quantitatively evaluate the efficacy of induced hypotensive anesthesia in decreasing facial soft tissue perfusion during orthognathic surgery using laser-assisted indocyanine green fluorescence angiography. This retrospective study involved the evaluation of 16 patients who underwent orthognathic surgery. Data collection included facial tissue perfusion of the bilateral cheeks and chin at normotension and with pharmacologically induced hypotensive anesthesia. There were statistically significant differences in the facial tissue perfusion at normal and depressed levels of blood pressure (P<0.001). This study used an objective measure to demonstrate the long-standing belief that hypotensive anesthesia is efficacious in reducing tissue perfusion in the surgical field. The data suggest that pharmacologically depressing the level of mean arterial pressure by 18% may result in a 41-52% decrease in facial soft tissue perfusion. This study reports a novel method of quantitative analysis.

High-power diode laser in the circumvestibular incision for Le Fort I osteotomy in orthognathic surgery: a prospective case series study

The incisions during orthognathic surgery are classically performed with conventional scalpel or electrocautery. Considering that the high-power diode laser surgery may provide advantages when compared to conventional incision techniques, the current study aimed to present a prospective case series of patients submitted to circumvestibular incision for Le Fort I osteotomy. Ten patients with dentofacial deformities who underwent to rapid assisted maxillary expansion or bimaxillary orthognathic surgery were enrolled in the study. All incisions were performed by a single surgeon using an 808-nm diode laser, with an optical fiber of 600 μm, at a power of 2.5 W, in a continuous-wave mode. The performance of the incision was evaluated by incision velocity, bleeding, edema, secondary infection, clinical healing, and pain. The velocity of the incision ranged from 0.10 to 0.20 mm/s (mean 0.13 ± 0.03 mm/s). Considering bleeding during the soft tissue incision, all surgeries were classified as absent bleeding. All patients presented a clinical healing of the surgical wound in a period that range from 3 to 5 weeks and experienced swelling during the follow-up period. On average, approximately 50% of the swelling had resolved after the third postoperative week, and 28.8% of swelling remained after 2 months after the surgery. The pain decreased after 2 and 3 days, and 90.0% of the patients reported no pain after 7 postoperative days. High-power diode laser is effective and safety during circumvestibular incisions for Le Fort I osteotomy in orthognathic surgery decreasing bleeding, surgery time, pain, and edema after orthognathic surgery.

Correction of Facial Deformity in Sturge-Weber Syndrome

Background:

Although previous studies have reported soft-tissue management in surgical treatment of Sturge–Weber syndrome (SWS), there are few reports describing facial bone surgery in this patient group. The purpose of this study is to examine the validity of our multidisciplinary algorithm for correcting facial deformities associated with SWS. To the best of our knowledge, this is the first study on orthognathic surgery for SWS patients.

Methods:

A retrospective chart review included 2 SWS patients who completed the surgical treatment algorithm. Radiographic and clinical data were recorded, and a treatment algorithm was derived.

Results:

According to the Roach classification, the first patient was classified as type I presenting with both facial and leptomeningeal vascular anomalies without glaucoma and the second patient as type II presenting only with a hemifacial capillary malformation. Considering positive findings in seizure history and intracranial vascular anomalies in the first case, the anesthetic management was modified to omit hypotensive anesthesia because of the potential risk of intracranial pressure elevation. Primarily, both patients underwent 2-jaw orthognathic surgery and facial bone contouring including genioplasty, zygomatic reduction, buccal fat pad removal, and masseter reduction without major complications. In the second step, the volume and distribution of facial soft tissues were altered by surgical resection and reposition. Both patients were satisfied with the surgical result.

Conclusions:

Our multidisciplinary algorithm can systematically detect potential risk factors. Correction of the asymmetric face by successive bone and soft-tissue surgery enables the patients to reduce their psychosocial burden and increase their quality of life.

The Effects of Oral Atenolol or Enalapril Premedication on Blood Loss and Hypotensive Anesthesia in Orthognathic Surgery

PURPOSE

The aim of this study was to evaluate the effects of premedication with oral atenolol or enalapril, in combination with remifentanil under sevoflurane anesthesia, on intraoperative blood loss by achieving adequate deliberate hypotension (DH) during orthognathic surgery. Furthermore, we investigated the impact thereof on the amount of nitroglycerin (NTG) administered as an adjuvant agent.

MATERIALS AND METHODS

Seventy-three patients undergoing orthognathic surgery were randomly allocated into one of three groups: an angiotensin converting enzyme inhibitor group (Group A, n=24) with enalapril 10 mg, a β blocker group (Group B, n=24) with atenolol 25 mg, or a control group (Group C, n=25) with placebo. All patients were premedicated orally 1 h before the induction of anesthesia. NTG was the only adjuvant agent used to achieve DH when mean arterial blood pressure (MAP) was not controlled, despite the administration of the maximum remifentanil dose (0.3 μg kg⁻¹ min⁻¹) with sevoflurane.

RESULTS

Seventy-two patients completed the study. Blood loss was significantly reduced in Group A, compared to Group C (adjusted p=0.045). Over the target range of MAP percentage during DH was significantly higher in Group C than in Groups A and B (adjusted p-values=0.007 and 0.006, respectively). The total amount of NTG administered was significantly less in Group A than Group C (adjusted p=0.015).

CONCLUSION

Premedication with enalapril (10 mg) combined with remifentanil under sevoflurane anesthesia attenuated blood loss and achieved satisfactory DH during orthognathic surgery. Furthermore, the amount of NTG was reduced during the surgery.

Hypotensive Anesthesia Is Associated With Shortened Length of Hospital Stay Following Orthognathic Surgery

PURPOSE

To evaluate the impact of induced hypotensive anesthesia on length of hospital stay (LOS) for patients undergoing maxillary Le Fort I osteotomy in isolation or in combination with mandibular orthognathic surgery.

MATERIALS AND METHODS

A retrospective cohort study design was implemented and patients undergoing a Le Fort I osteotomy as a component of orthognathic surgery at the Mayo Clinic from 2010 through 2014 were identified. The primary predictor variable was the presence of induced hypotensive anesthesia during orthognathic surgery. Hypotensive anesthesia was defined as at least 10 consecutive minutes of a mean arterial pressure no higher than 60 mmHg documented within the anesthetic record. The primary outcome variable was LOS in hours after completion of orthognathic surgery. The secondary outcome variable was the duration of surgery in hours. Multiple covariates also abstracted included patient age, patient gender, American Society of Anesthesiologists score, complexity of surgical procedure, and volume of intraoperative fluids administered during surgery. Univariable and multivariable models were developed to evaluate associations between the primary predictor variable and covariates relative to the primary and secondary outcome variables.

RESULTS

A total of 117 patients were identified undergoing Le Fort I orthognathic surgery in isolation or in combination with mandibular surgery. Induced hypotensive anesthesia was significantly associated with shortened LOS (odds ratio [OR] = 0.33; 95% confidence interval [CI], 0.12-0.88; P = .026) relative to patients with normotensive regimens. This association between hypotensive anesthesia and LOS remained statistically significant in a subgroup analysis of 47 patients in whom isolated Le Fort I surgery was performed (OR = 0.13; 95% CI, 0.03-0.62; P = .010). Induced hypotensive anesthesia was not statistically associated with shorter duration of surgery.

CONCLUSION

Induced hypotensive anesthesia represents a potential factor that minimizes postoperative LOS for patients undergoing routine maxillary orthognathic surgery alone or in combination with mandibular procedures. Hypotensive anesthesia does not appear to be effective in minimizing the duration of surgery within this same patient population.

Hypotensive anesthesia versus normotensive anesthesia during major maxillofacial surgery: a review of the literature

Steady blood pressure within normal limits during surgery is one of the markers of the ideal and skillful anesthesia. Yet, reduced blood pressure is advantageous in some settings because it can contribute to a reduction in overall blood loss and improve the surgical field conditions. Controlled hypotension during anesthesia or hypotensive anesthesia is often used in major maxillofacial operations. Since hypotensive anesthesia carries the risk of hypoperfusion to important organs and tissues, mainly the brain, heart, and kidneys, it cannot be applied safely in all patients. In this paper we review the medical literature regarding hypotensive anesthesia during major maxillofacial surgery, the means to achieve it, and the risks and benefits of this technique, in comparison to normotensive anesthesia.