How to decide skin incision

 When I work on patients with pectus excavatum, I incise the skin of their chests in different fashions. For some, I make incisions similar to the icon of Mercedes (a German automobile maker) (Figure 1); for others, I incise across the chest, with an incision line looking like a flying bird (Figure 2).

                                                             Figure 1

                                                           Figure 2

 I decide the skin incision’s fashion for each patient by referring to the structure of his/her thorax. My basic principles are: 1. Sever every bone hindering elevation of the concave part of the chest wall; 2. Minimize the length of skin incision.

  For instance, Figure 3 is a graphic image of the thorax of the patient in Figure 1. Before the operation, I explained, showing Figure 3 to the patient, as follows: “Your sternum presents deformity. It bends toward the back at point A. Therefore, I need to sever your sternum to straighten it at Point A. Similarly, the ribs distort inwards at the points indicated with arrows. Therefore, the ribs need to be severed at these points. Therefore, I make a Mercedes-type skin incision to expose all the points.”

                                                                Figure 3

                                                         Figure 4

 Almost all patients are happy with such explanation. However, I recently have found another way of explanation, which I think is more persuasive. I tell the patient to draw a circle on his/her chest wall around the area that he/she thinks sagged in. Then I let him/her draw a line corresponding to the circle (Figure 4). Thereafter, I ask: “We need to elevate the area inside the circle, right?” The answer: “Right.”

  I ask further, “We need to incise your skin to expose the chest wall and sever ribs on the circle. Can you describe an incision line on your chest wall that enables our access to the bones? You can minimize the skin incision. I’ll incise your skin as you instruct, as long as it enables my access to the chest wall.” The patient struggles to find the best answer to this geometrical question, and eventually draws a circle like in Figure 5. Through this sort of explanation, the patient can personally understand that the design I provide is the best solution.

                                                                 Figure 5

 The size of the circle can differ depending on the area of deformity. The patient in Figure 5 had a large concavity on his chest wall. Since the deformity extended to almost all of his thorax, I had to expose the entire chest wall to correct it, which required the skin incision in Figure 6. Although we made a long incision on the chest wall of the patient, we sutured the wound with greatest care, so the scar would gradually become inconspicuous. Figure 7 shows the condition of the scar two years after the operation.  

                           

                                                                        Figure 6

                     

                                                                             Figure 7

 

 

 

Why Should We Divide Sternum?

　Though many surgeons in Japan provide surgical treatment to patients with deformed chests, or pectus excavatum, they don’t necessarily do operations using current best practices. I often enlighten such surgeons with lectures at academic meetings, scientific papers, and articles at web sites like this.

 In this article, I explain how we should work on the sternum. The sternum is the bone at the center of the chest. The sternum takes different shapes between adults and children.

 These two images represent typical structures of the sternum in adults and children. The left image is that of an adult patient. Pay attention to the shape of the sternum. It is a single, unified plate. On the other hand, the sternum in the right image consists of four segments. This is a typical pattern for child patients. Let’s consider how this structural difference affects the operation.  

 This figure demonstrates the basic principle of the operation. First, the concave chest wall is elevated. Then metal plates are placed underneath the elevated chest wall to keep it at the corrected position. When operating on child patients, it is not so hard to elevate the chest wall, because the sternum is flexible.

 The following images are the pre- and post- operative shapes of a child patient’s chest. Note the segmented sternum in the left image. The segments are connected with joints, and the sternum is flexible. So the chest wall can be elevated easily.

 With child patients, thanks to the flexibility of the chest wall, we don’t need to cut any bones. We can correct the chest wall by simply placing one or two bars. The insertion can be done through short skin incisions.

 In summary, the chest wall of a child patient is soft because of the flexibility of the sternum. Therefore, the chest wall can be elevated with little force. The only thing the surgeon should do is to place bars to keep the elevated chest wall at its correct position. So the operation is easy and can be done through short skin incisions.  

 However, adult patients are quite different stories. Although a considerable number of surgeons use the same technique for adult patients as that for child patients, this is problematic. Direct application of the technique for child patients to adult patients often causes trouble. 

 For instance, a patient recently requested I perform secondary treatment. She had received surgery at a university hospital in Tokyo. Although her chest shape improved to some extent with the first surgery, she was not happy, because she was annoyed by serious pain after the operation. I took computer tomography images of the patient including the one on the right side of the following figure. I wanted to know how the shape of the chest wall had been changed by the first operation. To evaluate the morphological change, I requested the surgeon who had done the previous operation to provide me preoperative images of the patient. He agreed and sent me preoperative images. The left side is one of those images. The right side is one of the postoperative images we had taken at our hospital. The shape of the chest wall appears to have improved.  

 However, the patient had been annoyed by serious pain. From immediately after the operation, the pain had persisted for more than 6 months, when she visited me seeking treatment.

  Looking at the images, I found the surgeon who had done the operation had simply applied the method for children directly to this patient, though she was in her forties.

  I explained why surgeons should not apply child-appropriate technique directly to adult patients, showing the picture given below: Adults’ sternums are hard and inflexible. Furthermore, the ribs attached to the sternum are much harder than those of children.   

 Therefore, when surgeons correct the shape of the adult chest wall, they have to pull it up forcibly. Accordingly, the elevated chest wall tends to go back to its original, concave position. The bar supporting the chest wall is strongly pushed downward, producing intense stress at the points where the bar and ribs intersect. This stress naturally causes pain. This is how postoperative pain develops in adult patients in cases where they are treated with techniques for CHILD PATIENTS.     

 The images of the above figure were those of another adult patient. Pay attention to the ribs supporting the bars. They had sagged toward the back. This finding supports the above-stated theory.

 Then, what should surgeons do to avoid such problems? Several techniques are available. One such technique is to make the sternum flexible by dividing it. After the sternum is divided, the chest wall can be elevated with less force, producing less counter-stress on the bar. So, the patients are less likely to feel pain.

 The following images are those of a patient in whom we divided the sternum to make it flexible. The divisions reduce the stress from the bars.

 

 

fat transplantation cannot cure pectus excavatum

  Fat-injection is one of the most common operations in aesthetic surgery. Surgeons squeeze out fat tissues from the patient’s belly, upper arm, and thighs using a special apparatus. This apparatus is a sort of injector with thick needles. The fat tissues are injected into other parts of the body (mainly, women’s breasts). This sort of operation is easy to conduct and requires neither high-level surgical skills nor costly facilities. So, lots of cosmetic surgeons conduct fat-suction and fat-injection at their private clinics.

 Some surgeons boldly advertise “We cure pectus excavatum with fat injection.” However, this is a prime example of hyperbole. Solely performing fat injection doesn’t satisfy most patients with pectus excavatum. It is surely true that usually the greatest concern of pectus excavatum patients is their chest shape. However, it isn’t their sole concern. Besides the appearance of the chest wall, they are very often troubled by occasional chest pain, breathlessness, and easy fatigue. These symptoms are caused because their hearts are pressed by their chest walls. The symptoms never disappear even if the appearance of the chest wall is improved to some extent by the injection of fat. 

 Nevertheless, many patients visit private aesthetic clinics, lured by their gorgeous advertisements. When the patients go to such private clinics, surgeons strongly encourage patients to receive a combined operation of fat-suction (from the belly) and fat-injection (to the breast). The surgeon charges fees for both fat-suction and fat-injection. Usually, the total fee amounts to 5,000 to 20,000 dollars. 40 to 60 percent of the fee is paid to the surgeons. Thus, fat injection is a very lucrative operation for such surgeons.  

 I think patients should be more careful about receiving fat injection. However, I don’t totally reject fat injection, because it can be an effective maneuver in limited conditions. For instance, unevenness might persist even if the chest wall is elevated with pectus excavatum surgery. Injection of fat tissue is effective in smoothing the contour of the chest wall.

脂肪注入で漏斗胸は治せるか？

　美容外科のひとつに、「脂肪吸引」や「脂肪移植」と呼ばれる分野があります。読んで字のごとく、体の一部から脂肪を吸い取るのが「脂肪吸引」で、それを移植するのが「脂肪移植」です。脂肪吸引と脂肪移植に特化したクリニック（というかチェーン店）も存在します。こうしたクリニックで「漏斗胸を治せます」と宣伝しているところがあります。

　しかしこれは誇大広告であると筆者は思います。大多数の場合、脂肪注入だけでは漏斗胸は改善しません。脂肪注入では胸郭の形をまったく変えないからです。漏斗胸患者さんは、胸の形について悩み、それを改善したくて病院においでになります。しかし胸の以外に、何らかの心肺機能も伴っている場合がほとんどです。これは胸壁によって心臓と肺が押されているためです。

　脂肪注入を行う場合、まず腹部もしくは大腿部から脂肪を採取します。大きな注射器を用いて液状の脂肪を採取し、それを乳房や大胸筋の中に注射します。こうした組織は胸郭の外にあります。それゆえ脂肪を注入しても、胸壁の形が改善することは絶対にありません。なぜなら、胸壁による圧迫は残ったままだからです。

　それゆえ脂肪注入を行っても、心肺機能には全くプラスの影響がありません。

若い漏斗胸患者さんの場合、胸痛や息切れなど、明らかな自覚症状がない場合もあります。しかしよく聞いてみると、「体育の際に息切れがしやすい」とか「冷え性」であるといった、微細な症状はあるものです。胸郭の陥没を修正することにより、こうした症状は軽減しえます。しかし脂肪注入を行っても、こうした症状は決してなくなりません。

　美容クリニックへ行くと、患者さんは脂肪注入の手術をお受けになることを強く勧められます。これは多くの美容クリニックでは医師の給与が歩合制になっていて、手術費用の40～60％が医師に支払われるからです（脂肪注入の料金は1回につき100万円～300万円ほどかかります）。このように巨大なインセンティブがあるので、個人クリニックの美容外科医たちは患者に脂肪移植を勧めるのです。

　ただし、脂肪注入が漏斗胸の治療にまったく役にたたないというわけではありません。一部の患者では、胸壁の変形が軽度で、心肺機能がほとんど正常です。こうした患者さんの場合には胸壁の陥没を脂肪注入で治すことも、選択のひとつです。

　また、胸郭の変形を治しても、胸壁の形に微細な凹凸が残る場合があります。胸壁の輪郭をブラッシュアップするためのminor techniqueとしては、脂肪吸入は有用な手段です。

上記に述べるように、筆者は脂肪注入を完全に批判はしません。ある一定の状況では、有用な治療手段と思っています。

他院でナス法を受けた後、バーを抜くには（Problems with Incorrect Positioning of Pectus Excavatum Bars）

　私の外来には、胸壁の形に悩まれる患者さんが大勢、おいでになります。その中には他の病院で手術をお受けになった後に、「（初回の手術で入れた）バーを取り外してください」と言って手術をご希望になる方もおいでになります。

ご希望があれば手術は行っていますが、その際に、ちょっと気を付けなくてはいけない点があるのです。

　多くの病院では「ナス法」という方法で手術を行いますが、ナス法で漏斗胸の手術を行う場合、術者はバーを胸郭に誘導しなくてはいけません。この時、バーは胸壁上のどこかのポイントで、胸壁を貫く必要があります。左右のそれぞれにこうしたポイントが存在します。この点は“ヒンジ・ポイント”と言われますが、バーはこの点で支えられています。

　私はこの“ヒンジ・ポイント”が、なるべく内側の、乳頭のあたりに来るようにしています（図１）。力学的にバーを安定させるためには、そうすることが必要だからです（理由は別に書きます）。しかしこのようにバーをポジショニングさせるのは技術的にむつかしいので（これも理由は別に書きます）、“ヒンジ・ポイント”を胸壁の外側（脇の下くらいの位置）に設定する外科医が、実にたくさんいます（図２）。

            

       　図１：正しいバーの入れ方　　　　　　　　図２：誤ったバーの入れ方

　そうするとバーを抜去する際に、ちょっと気を付けなくてはいけないのです。バーはU字型をしていますが、これを抜く際には、まっすぐに曲げ直さなくてはいけません。ただ、外科医が直接、操作を行うことができるのは、“ヒンジ・ポイント”より外側の部分だけなのです。なぜなら、バーのうち、胸郭（「あばら」）に潜っている部分に対しては操作ができないからです。

“ヒンジ・ポイント”を内側に設定した場合には、U字型のバーを、ほぼまっすぐにすることができます。バーのかたちをまっすぐにしておけば、「スッ」とバーを抜くことができます。

しかし最初の手術で、バーを挿入した位置が外側すぎる場合には、バーを完全にまっすぐにすることはできません。外科医が曲げることができるのは、胸壁の外の部分だけです。ゆえに、なるべくまっすぐにしようと思っても、図に示したように“W”型にすることしかできません（図３）。

この状態でバーを引き抜くとき、“W”の角で心臓が押されます。バーのエッジはなめらかですから、仮にバーがそのように心臓を押したとしても、心臓が傷つくことはまずないでしょう。しかし一時的にせよ、心臓が圧迫されることは、やはりよくありません。私の患者さんの中には、他の病院で手術を受けられたあとに（その結果に満足せず）修正を求めてこられる方がたくさんおいでになります。正しい理論に沿って手術が行われていない患者さんに対してリカバリーをするのは多かれ少なかれ苦労するのですが、今日はその一つの理由をご紹介しました。

　　

図３：”W”型に曲げざるを得ない　　　　　　　　　　図４：抜去の際に、心臓を圧迫する

　Many patients request that I correct their chest shapes after they receive surgery at other hospitals. These requests often annoy me, because re-correction of thorax shape is much more difficult than to achieve good results with the first operation. The readers might understand the difficulty, by assuming themselves as carpenters. A client comes to you and says, “I’ve had my house constructed, but I’m not satisfied with it. It’s neither as gorgeous nor as comfortable to live in as I had expected.” The person requests you rebuild the house. I believe you can easily imagine that such correction is much more challenging than building a house from scratch. To deepen your comprehension, I’ll provide more minute explanation by referring to actual problems I’ve encountered.

　A 45-year-old male patient received surgery at a private hospital in Shikoku to correct his pectus excavatum. A correction bar was placed in his thorax in the primary surgery. He requested that I remove the bar. I asked why he didn’t ask the surgeon who had done the initial surgery to remove the bar. The patient said he was not satisfied with the hospital. “In particular”―he said―“The surgeon didn’t pay attention to pain control. I had terrible pain for several days and asked the surgeon to relieve it. However, he only prescribed suppositories. They didn’t work at all!”

　I explained to him, “Some of your ribs and cartilages were bent in the first operation. So, it is natural that you had pain in the previous operation. However, the secondary operation is another story. The shape of your chest wall has already stabilized. Simply removing the bar won’t cause stress on your bones and cartilages. Therefore, it is unlikely that you will have as intense pain as after the initial operation, even if the surgeon doesn’t take enough care. I recommend you ask the surgeon to remove his bars.”

　Nevertheless, the patient insisted to receive operation at my hospital. So, I decided to work on him.  I completed the second operation successfully, but I encountered a minor problem due to incorrect positioning of the bars in the first operation. In my method, I place bars so that the bars rest on ribs at their most anterior points (Figure 1).     

　However, the bar had been supported at points much lower and much more outside than I would place them (Figure 2). When placed this way, the bars aren’t dynamically stable (I’ll explain the reasons in another column). Besides the dynamic instability, placing the bars like in Figure 2 increases the risk in bar removal. In Figure 2, the bar penetrates the thorax at lateral points. The parts of the bar between its ends and these points exist outside of the thorax.

　 When surgeons remove correction bars, they first straighten the bar before removing it. The surgeon cannot work on the part of the bar inside of the thorax. It is only the part outside of the thorax that the surgeon can bend. So, the surgeon cannot make the bar completely straight. After being bent, the bar takes a shape similar to that of “W” (Figure 3). This shape is not ideal in removing the bar, because it presses on the heart in the process of the removal (Figure 4). The heart may very rarely be hurt. Nevertheless, I believe even such tiny risks should be avoided.