Gong-Yin Zhao, Yu-Ji Wang, Nan-Wei Xu, Feng Liu

Gong-Yin Zhao, Yu-Ji Wang, Nan-Wei Xu, Department of Orthopedics, The Affiliated Changzhou NO. 2 People’s Hospital of Nanjing Medical University, Changzhou 213003, Jiangsu Province,China

Feng Liu, Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210000, Jiangsu Province, China

Corresponding author: Feng Liu, MD, PhD, Chief Doctor, Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210000, Jiangsu Province, China. njliuf@163.com

Abstract

Key words: Total hip arthroplasty; Direct anterior approach; Lateral circumflex femoral artery; Ligation; Blood loss; Electrocautery

INTRODUCTION

Hemorrhage during a total hip arthroplasty (THA) involves an expected blood loss as well as perioperative “hidden blood loss”[1-4]. Specific measures designed to minimize blood loss are important not only to decrease unnecessary bleeding, but also to promote a more rapid, functional recovery and to decrease the need for blood transfusion[5,6]. The direct anterior approach (DAA) to performing a THA utilizes an approach via the intermuscular plane, which is designed to minimize muscle damage and blood loss. Moreover, this approach is associated with accelerated postoperative recovery and low rates of dislocation.

The lateral circumflex femoral artery (LCFA) arises from the profunda femoris artery or the femoral artery and supplies blood to the inferior-medial cortex of the femoral neck and the periarticular soft tissues. In most cases, the LCFA usually divides into an ascending and a descending branch; however, in some patients, the LCFA has a third, transverse branch[7-10]. During a DAA, the ascending and transverse branches of LCFA span across the incision between the distal and the middle third of this approach. Most surgeons believe that these vessels are involved in extra blood loss and therefore believe that their ligation is necessary to minimize otherwise unnecessary bleeding[11-14]. Their control via ligation of their pedicle is a troublesome procedure for orthopedists, requiring a bit of extra time and effort to dissect the pedicle.

The aim of this study was to investigate whether ligation of the pedicle of the LCFA will decrease blood loss and lead to better surgical results compared to electrocauterization of the branches off the LCFA.

MATERIALS AND METHODS

Subjects

We conducted a 2-year study of 103 patients with femoral neck fractures undergoing a THA via a DAA from October 2016 to October 2018. Patients older than 90 years (n =7) were excluded. Patients who had a history of stroke (n = 10), hepatic or renal failure(n = 3), coagulation abnormalities (n = 4), taking anticoagulants (n = 6), myocardial infarction (n = 3), previous venous thromboembolism (n = 4), and surgery lasting more than 90 min or had an unexpected condition, such as an intraoperative fracture(n = 6) were also excluded.

In the end, 60 patients were enrolled in the study, ranging in age from 52- to 87-years-old. Patients were numbered according to the order of admission. Patients with an odd number were included in group A, and patients with even number were included in group B. The patients were assigned to groups by a supervisor nurse who did not know the surgery situation. Patients who underwent ligation of the pedicle comprised Group A; those whose branches off the LCFA were treated by electrocautery comprised Group B. Approval for this study was obtained from the Institutional Review Board committees of the authors’ affiliated institutions. The patients were informed of the intraoperative vascular management and signed the informed consent after obtaining the consent. Patients were blinded of their grouping.

Operative technique

For this DAA approach, a vertical incision was made over the medial edge of the tensor fasciae lata muscle (TFLM). After the location of the TFLM was confirmed, the overlying fascia was incised and the plane between the TFLM and rectus femoris muscles was identified and dissected with retraction of the TFLM laterally. The branches of the LCFA were seen to course anterior to the underlying fat (Figure 1A).The pedicle of the LCFA in group A was ligated with silk suture material and transected; this maneuver required dissection of their pedicles deep into the wound.In group B, the branches off the LCFA were controlled with electrocautery set at a power of 55 W. Electrocautery was easily and rapidly carried out along the blood vessels, and satisfactory hemostasis was evident (Figure 1B).

All operations were performed by the same group of surgeons using the DAA.Each patient received a cementless hip stem prosthesis and a cementless acetabular cup from a single manufacturer (Waldemar Link Gmbh and Co, Hamburg, Germany).After the operation, all patients received subcutaneous injections of 4100 IU of low molecular weight heparin calcium once a day and application of mechanical intermittent pneumatic compression devices in bed twice a day (30 min each time) to prevent venous thromboembolism. All patients started to walk with a walking aid within 24 h of surgery.

We measured the decrease in hemoglobin (Hgb), estimated intraoperative blood loss, actual (calculated) blood loss, transfusion rate, re-bleeding rate, and hematoma rate. The decrease in Hgb was associated with changes in Hgb concentrations between the preoperative value and the values at 48 h postoperative. The actual blood loss was calculated using the equation: Actual blood loss = blood volume [preoperative hematocrit - postoperative hematocrit]/[mean hematocrit], where blood volume =body weight in kilograms × 70 mL/kg[15].

The estimated blood loss was determined from the anesthesia record and postoperative drainage. The indications for transfusion were Hgb ＜ 7 g/L and/or hematocrit ＜ 22 in patients less than 75 years of age. In contrast, patients older than 75 years with Hgb ＜ 9 g/L were given transfusions if the clinical evaluation showed tachycardia, poor urine output, hypotension, fatigue, light-headedness, or other symptoms of acute anemia as determined by the postoperative team. The duration of the operation was determined from the anesthesia record. The relevant clinical data were collected by a single observer, who was blinded to the patient’s operative approach.

Statistical analysis

Data were recorded and collected into an Excel database (Microsoft). Statistical analysis was performed using GraphPad Prism 5. All variables were analyzed using a paired Student’s t test except the rates of transfusion, hematoma, re-bleeding, and prosthetic loosening, which were analyzed using Fisher’s exact test. Statistical significance was defined at P ＜ 0.05. All variables were analyzed by an independent orthopedist who was not part of the operative team, was blinded to the patient groups, and who received no funding, has no competing interests, and confirmed the accuracy of the findings.

Figure 1 Plane between tensor fasciae lata muscle and rectus femoris showing the branches of the lateral circumflex femoral artery spanning the wound.“Star” represents the ascending branch of lateral circumflex femoral artery. “Diamond” represents the fat strip.

RESULTS

Patient characteristics

From October 2016 to October 2017, 103 patients scheduled for a primary THA with a single surgeon were screened and assessed for eligibility. Forty-three of the patients were excluded for failing to meet the selection criteria. After randomization, 60 patients (30 patients in group A; 30 patients in group B) were included in the statistical analysis of our trial (Figure 2). The patients were evenly matched in demographics (Table 1). There were no statistically significant differences in body mass index, age, or sex (all P values were ＞ 0.05).

Postoperative outcomes

There were no statistically significant differences in the decrease of Hgb between group A and group B (20.9 ± 7.0 g vs 21.2 ± 4.9 g, respectively; P = 0.805) and the actual calculated blood loss (784 ± 125 mL vs 722 ± 152 mL). However, there was a trend in group A towards having more blood loss (P = 0.078). However, this trend did not explain the problem, and the difference would be narrowed after the sample size increased. The estimated blood loss (344 ± 88 mL vs 346 ± 73 mL; P ＞ 0.5) did not show significant differences. Importantly, there were no statistically significant differences between the two methods in the rate of blood transfusion, hematoma, or re-bleeding(P ＞ 0.2 for each) (Table 2).

DISCUSSION

DAA is associated with less trauma than the posterolateral approach for THA.Because it is a less traumatic approach, finding a method to address the relevant blood vessels to prevent unnecessary bleeding during the operation is particularly important. In the posterolateral approach, the pedicle to be ligated is the medial circumflex femoral artery. Chiron et al[6]reported that ligation of the pedicle of the medial circumflex femoral artery can decrease bleeding effectively during a posterolateral approach. In the DAA, the ascending branch of LCFA is the important vessel in the surgical field and must be controlled. The LCFA originates from the profunda femoris artery or the common femoral artery. The ascending branch continues along the capsule and crosses the hip joint to supply the anterolateral capsule and thereby crosses the operative field in a DAA[16,17]. Because it is the donor and must be anastomosed by vascularized grafts in the treatment of osteonecrosis of the femoral head, the ascending branch also can be used as both a pedicle and free flap. Because the LCFA provides a less plentiful blood supply than the medial circumflex femoral artery, ligating it does not appear to have any pronounced negative effects[10,18,19].

Previous studies have described a number of surgical procedures and techniques during a DAA, but few works have focused on the treatment of this troublesome vessel[15,20-22]. Our study compared the consequences of two methods of dealing with the ascending branch of LCFA during a DAA and demonstrated that formal ligation of the ascending branch of the LCFA is unnecessary. Electrocautery is a simple and effective method to control this vessel; electrocautery can transect the vessel without causing bleeding, which simplifies the procedure. In the ligation group, there was no increased risk of re-bleeding or hematoma, suggesting that it is a relatively safehemostatic technique and can replace the dissection of and subsequent ligation of its pedicle as a means of preventing unnecessary bleeding from the ascending branch of the LCFA.

Table 1 Demographics1 of patients in both groups

We emphasize that our study did not include patients with coagulation disorders,hematologic disorders, or other related diseases affecting coagulation. For these patients, whether suture ligating the vessel is safe and effective still needs further verification. This study should be supplemented by a larger, randomized study to verify these preliminary conclusions.

Leaving the lateral circumflex pedicle unligated and addressing any bleeding using electrocauterization alone does not increase blood loss in the perioperative period and does not increase the incidence of postoperative hematomas in patients undergoing THA by a DAA. Although ligation did not significantly increase the operative time, it did require some additional time and effort, while offering no obvious benefit.Therefore, it is unnecessary to ligate the LCFA during a DAA.

Table 2 Comparison of group outcomes1

Figure 2 Flow diagram illustrating patients enrolled in the study.

ARTICLE HIGHLIGHTS

Research background

Direct anterior approach total hip arthroplasty is widely accepted and becoming more and more popular all over the world. More orthopedists have switched from posterior to anterior approaches. Although the procedure is generally the same, no consensus has been reached on some details.

Research motivation

In the direct anterior approach, there are different opinions on the treatment of the ascending branch of the lateral femoral circumflex artery. The hope is that these studies will lead to a consensus on some of the details of direct anterior approach total hip arthroplasty.

Research objectives

Whether ligation of the ascending branch of the lateral femoral circumflex artery during direct anterior approach total hip arthroplasty is advantageous in reducing bleeding and whether this procedure is necessary.

Research methods

The manuscript compared the surgical bleeding, hemoglobin reduction, hematoma rate, and other indicators of two groups that received different treatments for the ascending branch of the lateral femoral circumflex artery during direct anterior approach total hip arthroplasty.

Research results

According to the results, the ligation of the ascending branch of the lateral femoral circumflex artery was not a necessary procedure. Electrocautery is a simple and effective method. However,due to the small sample size and short follow-up time, further observation is needed to see whether there is any difference between the two treatment methods.

Research conclusions

The intraoperative and postoperative blood loss were calculated to indirectly reflect vascular bleeding. Excision of the ascending branch of the lateral femoral artery by electrocautery did not increase bleeding. In the treatment of the ascending branch of the lateral circumflex femoral artery, cumbersome ligation can be replaced by electrocoagulation.

Research perspectives

Ligation is unnecessary and should be replaced by electrocautery in the treatment of the lateral circumflex femoral artery during the direct anterior approach total hip arthroplasty.