This survey covered a total of 636 respondents working in 13 hospitals in the city-province of Kinshasa (University Hospital of Kinshasa, Provincial Reference Hospital of Kinshasa, General Hospital of Kintambo, Central Military Hospital of Kokolo, General Hospital of Matete, Initiative Plus Hospital, Ngaliema Clinic, Ngaliema Medical Center, Hospital Center Monkole, Saint Joseph Hospital, Biamba Marie Mutombo Hospital, China-Congo Friendship Hospital, Makala General Hospital).

Among the respondents, there were 510 men and 126 women, with a sex ratio (M/F) of 4.05. The age group of 25 to 35 years old was the most representative with 46.2% of respondents while those over 45 years old were the least representative with 14.2% of respondents. Women were younger than men (p < 0.001). 80.2 % of respondents studied at a public university. There were twice as many women trained in public universities as in private universities (p < 0.001). Most of the respondents were general practitioners or specialist doctors with 48.1% and 37.7% respectively. There were more male than female specialist doctors (16.5% vs 4.8%) (p < 0.001).

Among the respondents, 85.8% were general practitioners, 6.6% surgeons, 3.3% gynecologists, 2.7% internists and 1.6% pediatricians. In terms of specialties, there were fewer female gynecologists (4.8%) than general practitioners (95.2%) (p < 0.001). More than half of the respondents (56.6%) had been practicing medical profession for more than 5 years while 20.1% had been practicing for 2 years (p < 0.001). 39.6% of respondents worked in both the public and private sectors while 38.7% worked in the public sector. We found a statistically significant link between seniority and gender, also between the sector of practice and the gender of the respondents (p < 0.001). There were older men in the profession than women (62.4% vs 33.3%). While there were more women working in private hospitals than men (47.6% vs. 15.3%).

In terms of general knowledge about abdominoplasty, almost all of the respondents, 93.4%, had heard about abdominoplasty while 36.8% knew how to define it fairly correctly. All of the respondent women (100%), had heard about abdominoplasty (p < 0.001). Among all respondents, only 34.9% had learned these concepts as part of a course organized at the medical school. All respondents, i.e. 100%, knew the body mass index (BMI) classification according to the World Health Organization (WHO) ( Table 1 ).

Most of respondents knew that abdominoplasty could be performed in Kinshasa (80.9%) and that plastic surgery was the specialty that performed it (83%), while a minority (29.2%) knew about useful supplement examination. We found a statistically significant link between gender and knowledge of the practice of abdominoplasty in Kinshasa as well as knowledge of the involved specialty. There were fewer women informed about the practice of abdominoplasty in Kinshasa than men (70% vs 83.6%) (p = 0.001). While there were more women informed about the surgical specialty involved in the practice of abdominoplasty than men (p < 0.001) ( Table 1 ).

A few respondents had knowledge about the complications of abdominoplasty (21.7%), about the association between liposuction and abdominoplasty (21.6%), between smoking and abdominoplasty (29.3 %). No respondent knew the circumstances of combining liposuction with abdominoplasty or the essential postoperative measures after an abdominoplasty ( Table 2 ).

The level of general knowledge of the respondents was good in 65.3% of cases, excellent in 25.3% of cases and low level in 9.4% of cases. We did not find a link between the level of general knowledge of abdominoplasty and gender (p = 0.062).

The level of specific knowledge about abdominoplasty was low in 84.4% of cases and good in 15.6% of cases. No respondent had an excellent level of specific knowledge. We did not find a link between the level of specific knowledge of abdominoplasty and gender (p = 0.229).

The good level of general knowledge decreased with the age of the respondents (p < 0.001) while the excellent level decreased with the training levels of the respondents (p = 0.002). We did not find a significant statistical link between gender, university of training and level of general knowledge about abdominoplasty ( Table 3 ).

Surgeons and gynecologists had good knowledge compared to other medical specialties (p < 0.001), while the good level of knowledge increased gradually with seniority. Respondents with more than 5 years of seniority had approximately 3 times the good level of knowledge than practitioners with less than 2 years of seniority. Doctors working in the public sector had an excellent level of general knowledge than those working in the private sector (47.8% vs 18.6%) (p = 0.017) ( Table 3 ).

No doctor who participated in the current survey had an excellent level of specific knowledge about abdominoplasty ( Table 4 ). Apart from medical specialties, no statistically significant link was found between other epidemiological variables (sex, age groups, university of training, level of medical training, seniority, and

field of practice) and the level of specific knowledge of respondents on abdominoplasty. Surgeons and gynecologists had a good level of specific knowledge compared to other medical specialties (p = 0.005) ( Table 4 ).

The definition of abdominoplasty includes the removal of localized excess skin and fat, the suprapubic incision and transposition of the umbilicus. In this study, 93.4% of doctors claimed to have already heard of abdominoplasty, only a minority (36.8%) knew how to define it correctly. Several reasons can justify this contrast: the fact that 85% of doctors were general practitioners justifying the relatively young age of the respondents (85.8% aged fewer than 45), the scarcity of plastic surgery services and the lack of teaching of plastic surgery at the undergraduate level in medical schools [19] . Hence a minority of doctors (34.9%) had learned the concepts of abdominoplasty as part of a course at medical school. Indeed, abdominoplasty is one of the multiple surgical procedures for repairing the abdomen for aesthetic or functional purposes [7] [8] . It aims to obtain a narrower and flatter abdomen ( Figure 1 ) by correcting 3 parietal planes: the cutaneous plane, the fatty plane, the musculo- aponeurotic plane.

The skin is put into tension for as discreet a scarring as possible. Its correction is done either by extended abdominoplasties (classic abdominoplasties) or by localized abdominoplasties (mini-abdominoplasties) [3] . Extended abdominoplasties are characterized by significant undermining skin to expose a loose abdominal wall to allow skin lifting [7] [8] . They are mainly represented by plasties with transverse or horizontal incisions, and rarely by plasties with vertical or mixed incisions. Low transverse abdominoplasty with transposition of the umbilicus performs a resection of the subumbilical cutaneous-fatty plane from a suprapubic incision to the costal and xiphoid level. The umbilicus with a circular collar is then released from its skin attachments to allow the upper flap to be lowered onto the lower bank.

Finally comes the exteriorization of the umbilicus on this upper flap [3] [8] . There are also other variants of the classic abdominoplasty: upper high tension abdominoplasty, transverse abdominoplasty with neo-umbilicoplasty, circular

abdominal dermolipectomy [3] . Fat plane correction is the domain of blunt cannula liposuction and is often associated with abdominoplasty [3] [9] . Correction of the musculo-aponeurotic plane is necessary in case of its relaxation and/or diastasis of the rectus abdominis muscle. Most of the time, plication is carried out using inverting U-shaped points [3] to restore the tensor effect of the anterior aponeurosis.

Let us remember that in this survey 19.1% of doctors did not know that this surgery was possible in Kinshasa and 17% did not know the surgical specialty involved. These results once again demonstrate the need for education and popularization of the concepts of abdominoplasty by educators and policy makers through different communication channels such as the media.

In addition, the level of general knowledge was excellent, at only 25.3%. This excellent level logically decreased with the level of training of doctors while the good level of knowledge decreased with the age of the respondents. Most doctors (70.8%), did not master the useful additional examination preoperatively.

Indeed, several additional examinations are useful preoperatively (laboratory test in particular blood sugar level, hemoglobin level; imaging examinations in particular abdominal TDM, abdominal ultrasound, Doppler ultrasound of the lower limbs). Determining the preoperative hemoglobin level is of particular importance, especially in male subjects undergoing abdominoplasty because of the increased risk of bleeding [11] . Dinahet T. et al. in a retrospective, single-center study, including a case group of 105 male subjects and a control group of 105 women who underwent anterior (n = 70) and circular abdominoplasty (n = 35) highlighted an increased risk of developing a hemorrhagic complication, mainly a hematoma or the need for an external blood supply, in the male group (OR = 2.72 [1.03 - 7.14]) [11] .

The factors incriminated are the larger caliber of peripheral vessels in men20, the overrepresentation of hypertension in men, excess weight, as well as greater cardiac output [11] . Hence, the importance of taking pre, per and postoperative precautions (globular supplementation, the use of surgical clips or ligatures of the main perforating pedicles or even the use of tranexamic acid [20] , drain installation).

Abdominal TDM or abdominal ultrasounds are not only used to demonstrate a rectus diastasis already visible on physical examination. They also help to exclude the presence of a clinically occult hernia, often in the umbilical region which can lead to the intraperitoneal passage of a liposuction cannula with a risk of visceral perforation [21] . Doppler ultrasound of the lower limbs is useful in subjects with a medical history of deep vein thrombosis of the lower limbs and in those with risk factors such as venous insufficiency [22] .

The results of this survey demonstrate a remarkable insufficiency of doctors in the city-province of Kinshasa with specific knowledge of abdominoplasty. Indeed, no doctor presented an excellent level of specific knowledge and 84.4% of doctors had a low level. Only surgeons and gynecologists have a good level of specific knowledge. The evaluation of the level of specific knowledge in this study was based on the interest in liposuction, the circumstances of its association with abdominoplasty, smoking as a contraindication, complications and essential postoperative measures.

Cannula liposuction, which is a procedure developed by Illouz in 1977 and popularized in 1982 [3] [9] , is intended for the correction of the fatty plane. It consists of the suction of fat cells, the creation of tunnels likely to lead during their healing, and skin retraction with rewrapping of the skin. It is used in the case of deep fat, which cannot be easily mobilized, mainly in the subumbilical region. Its complications are linked either to a very deep aspiration which can cause lesions of the musculo-aponeurotic plane, or even to the intra-abdominal viscera [21] , or to superficial aspiration leading to retraction of the dermis with skin adhesions on the aponeurotic plane which is very difficult to treat secondarily [3] .

Liposuction is often associated with an infiltration of adrenaline-filled physiological serum to prevent the risk of hemorrhage and facilitate the creation of the tunnels. Primary liposuction is very often combined with an abdominoplasty to minimize scarring [3] , in the absence of an aponeurotic parietal defect and a BMI greater than 30 kg/m² [3] [9] [21] . In this study, 21.6% of doctors knew that liposuction could be associated with abdominoplasty, but none of them knew the circumstances of this association. Likewise, minority of doctors (29.3%) knew that smoking was a contraindication to abdominoplasty. Remember that in addition to smoking, other contraindications for this procedure are planning a pregnancy in the near future, an unstable weight, a BMI of more than 30 kg/m² [3] [8] [9] .

If no respondent knew the essential postoperative measures of abdominoplasty, some respondents (21.7%) had knowledge of the complications of abdominoplasty even though abdominoplasty is known to have a high complication rate [10] . This rate is particularly variable in the literature, ranging from 4% to 67% [10] [23] . Some authors categorize them into early complications and long term complications [5] , others distinguish them into major complications and minor complications [24] . Several authors do not include disunions and delays in healing among the complications. Hematomas are diagnosed clinically by the appearance of swelling, early induration at the surgical site, pain in the area, associated or not with deglobulization [6] [11] . Seroma formation is the most common complication of abdominoplasty ranging from 0 - 30% approximately [6] [10] .

Seroma formation is largely due to significant separation during the operation [7] [8] [10] . It is a source of discomfort for the patient, prolongation of treatments and secondary complications such as infection, healing disorders and encystment [25] . The infection rate of abdominoplasties varies between 1% and 2%. It is higher in cases of immune depression than in diabetic patients [7] [8] . In addition to the complications mentioned above, other complications of abdominoplasty are skin necrosis and dehiscence of the surgical wound, the onset of keloid or hypertrophic scars, irregularities due to insufficient fat reduction or residual lipomeria [6] [7] [8] . Pulmonary embolism is a rare but potentially fatal complication of abdominoplasty [7] [8] [10] . The prevention of venous thrombosis and pulmonary embolism is based on the recommendations of the French Society of Anesthesia and Resuscitation (SFAR) with preventive anticoagulation which begins postoperatively, the wearing of intermittent pneumatic compressions and above all, getting up as soon as possible [24] [26] . Careful selection of patients can limit postoperative complications [24] .

This survey certainly presents limitations related to the quality of the respondents (a single category of medical personnel), the non-randomization of the sample (not allowing the generalization of the results) and the non-integration of many other notions about abdominoplasty.

However, this study is the very first to assess the level of the doctors’ knowledge about the shape surgery which helped us review our knowledge of this procedure.

1. Sex: Male/Female

2. Age: <25 years; 35 years/< 36; 45 years/>45 years

3. University training institution

4. Medical training: General practitioner/Specialization/Specialist

5. If specialist, discipline

6. Number of years of professional practice as a Doctor

7. Sector of practice: Public/Private/Public and private

1. Have you already heard of abdominoplasty? Yes/No

2. Define abdominoplasty

3. What was your source of information? Courses/Training/Other sources of information (Specify)

4. Do you know the WHO classification of the Body Mass Index? Yes/No

5. Is there a determining link between BMI and the indication for abdominoplasty? Yes/No

6. In your opinion, which surgical specialty performs abdominoplasty?

7. Is abdominoplasty possible in Kinshasa? Yes/No

8. What are the additional examinations useful for abdominoplasty?

1. Can liposuction be associated with abdominoplasty? Yes/No

2. What are the circumstances of this association?

3. Is smoking a contraindication for abdominoplasty? Yes/No

4. What are the complications of abdominoplasty?

5. What are the essential postoperative measures?