What are the classic symptoms of diaphragmatic disease and what is the average age of onset of symptoms?
About 95% of cases of diaphragmatic endometriosis occur on the right diaphragm only, about 5% occur on the left diaphragm only and less than 1% of cases are bilateral (on both right and left sides simultaneously). This distribution represents the embryonic patterning of the disease. Since right-sided disease occurs far more commonly than left-sided disease or bilateral disease, most of the discussion below will speak to the majority of patients who have right-sided disease. The symptoms are virtually identical when the left diaphragm is involved. The classic symptoms of diaphragmatic endometriosis are right chest and shoulder pain prior to or during the menstrual flow. The pain can feel like it is deep in the chest, with radiation to the shoulder and sometimes up the right side of the neck or into the right arm. Some women state that the pain can feel like a muscular strain, even though they've not done anything particularly strenuous with their neck or arm. The pain can be aggravated by breathing and some women have to reduce activities because deeper breathing with exercise can aggravate the pain. Some women can go on to have pain all month long, but still have aggravation with menses. Women often relate the onset of their symptoms to the late teens or early twenties. Since the pain is mild at first, they may tend to ignore the symptoms. When the pain gets more noticeable, they may mention it to friends, family, or doctors, all of whom may be puzzled by the pain and may say it couldn't be due to endometriosis. Hiccuping is an uncommon symptom.

Is all diaphragmatic disease symptomatic?
Not all diaphragmatic disease is symptomatic. Some diaphragmatic endometriosis is very superficial and may not cause any symptoms. Symptomatic disease usually involves the full thickness of the diaphragm. The diaphragm is only about 1/4 inch thick, so it doesn't take too much for endometriosis to involve the full thickness of the diaphragm.

If diaphragmatic endometriosis is an incidental find during surgery, should it be treated or left alone?
One of the questions a surgeon must ask himself during surgery is whether a particular surgical action will improve a patient's life with acceptable risks. An incidental finding of diaphragmatic endometriosis during surgery implies that the patient has no symptoms referable to the diaphragm, or that symptoms were present but not mentioned to the doctor, or that symptoms were mentioned but the doctor wasn't listening. If the patient truly has no symptoms, then there would be no improvement of life that would occur with aggressive surgical treatment of the disease and generally such incidental disease should be left alone for that reason, although a confirmatory biopsy can be done with little risk to firmly establish the diagnosis.

Are there any dangers of not removing asymptomatic disease?
The only danger of not removing asymptomatic disease is that it might become symptomatic in the future. From my experience, I would estimate that the risk of asymptomatic disease becoming symptomatic is less than 20%.

Besides possible painful symptoms, is diaphragmatic disease ever associated with catamenial pneumothorax?
Most cases of diaphragmatic endometriosis are NOT associated with catmenial pneumothorax (lung collapse during menses). The symptoms of diaphragmatic endometriosis and catamenial pneumothorax are somewhat similar, although pneumothorax may include an element of breathlessness which is not characteristic of diaphragmatic endometriosis. Catamenial pneumothorax can occur in the absence of diaphragmatic endometriosis.

Is diaphragmatic disease potentially life-threatening?
Not by itself, although women with severe symptoms may occasionally consider doing away with themselves because no one seems to understand what is going on.

What are the difficulties in correctly diagnosing and identifying invasive diaphragmatic disease prior to and during surgery - why might the invasive disease be missed?
The first barrier to the correct diagnosis of diaphragmatic endometriosis occurs in the doctor's office. Diaphragmatic endometriosis is sufficiently rare (I saw about 30+ cases out of over 3,000 career cases of endometriosis) that most gynecologists will never see a patient with the disease. When a patient presents to her gyn, he may not recognize even characteristic symptoms because of the rarity of the disease. Some obstetricians who see gyn patients as a hobby may prescribe Lupron with the idea that if the pain does not go away with Lupron, then it can't be due to endometriosis. This errant notion is due to a very successful marketing campaign by the manufacturer of Lupron. Previous publications have shown that Lupron does not produce reliable symptom relief of diaphragmatic disease and even if symptoms are reduced, they return quickly after the medicine is stopped, just like pelvic endometriosis. Diaphragmatic endometriosis usually does not show up well on scans because it often lacks sufficient volume to be seen on a scan. This is partially a function of how thin the diaphragm is. The smaller a lesion is, the less likely it will show up on any scan. Most women with diaphragmatic endometriosis will have negative scans for this reason, so a negative scan is characteristic of diaphragmatic endometriosis. Most women with diaphragmatic endometriosis have severe pelvic and intestinal endometriosis, and the pelvic symptoms often are more long-standing and chronic than the diaphragmatic symptoms. Since the abdominal cavity is like a large bag with the pelvic organs and endometriosis at the bottom and the diaphragms at the top, some diaphragmatic symptoms may be explained away by blaming severe pelvic disease for irritating the entire peritoneal cavity, including the diaphragms. Indeed, it is known that an irritative pelvic process, such as bleeding from a tubal pregnancy or ruptured corpus luteum cyst, can also irritate the diaphragm and cause diaphragmatic symptoms. For this reason, the symptoms of diaphragmatic endometriosis can be blamed on severe pelvic disease and the correct diagnosis not thought of. Accurate diagnosis of diaphragmatic disease can only be made during surgery.ÊHowever, if the patient eventually comes to surgery, there are some barriers to correct diagnosis in the operating room, too. Since severe pelvic and intestinal disease may be the primary thing that is suspected (often reinforced by an ovarian cyst having been found on a scan), the surgeon's attention may be exclusively directed toward the pelvis and the diaphragm not even looked at. Many gyns do not routinely inspect the diaphragm during surgery anyway. If the surgeon does look at the diaphragm, not all of the right diaphragm may be visible. This is because the liver is in the right upper quadrant and can block the surgeon's view of the entire diaphragm if a laparoscope is inserted through the umbilicus. From a laparoscope viewing from an umbilical port, the anterior (toward the front of the body) diaphragm can be seen easily. Disease of the anterior diaphragm is usually superficial and may be asymptomatic. If a surgeon sees such sentinel Trojan Horse lesions, he may think that this represents all of the patient's disease and that this is responsible for diaphragmatic symptoms. Treating such disease will usually not relieve symptoms because symptomatic disease is virtually always found on the far rear side of the diaphragm where it is hidden from view by the large mass of the liver. Symptomatic disease is found along the posterior diaphragm, usually represented by several inflammatory angry lesions spread in a swath across several inches of the diaphragm. Disease in this area is the real culprit for the patient's symptoms but may be missed because the liver blocks the surgeon's view of this area.

How can this be avoided?
To view the posterior diaphragm, a second small diameter laparoscope can be placed under the right ribs and passed over the liver to view the posterior chest wall where the liver and diaphragm meet. This allows the most accurate surgical diagnosis.

Why does diaphragmatic disease usually only tend to form on the right side of the diaphragm?
Endometriosis follows fairly predictable patterns of involvement in the pelvis, intestines, urinary tract, inguinal canal and diaphragm. These patterns of involvement are what provide predictability to a disease which is often thought to be unpredictable by physicians who do not understand the disease. Whatever genetic or environmental influence that governs embryonic differentiation and migration of formative cells results in patterned tracts of tissue being laid down, in which tracts endometriosis will eventually form, if not already laid down in the tracts. The right-sided vs left-sided % of diaphragmatic disease is virtually identical to the right-sided vs left-sided % of endometriosis of the inguinal canal. Some prominent authors try to explain the predilection of right-sided disease on a non-existent peritoneal circulation sweeping refluxed endometrium from the fallopian tubes to the right diaphragm. This argument is objectionable for two reasons: 1. reflux menstruation is not the origin of any form of endometriosis; 2. some authors supporting such a circulation theory have altered published diagrams to support this theory, and alteration of diagrams without supporting evidence is scientific fraud.

In your own series of patients who underwent the excision of diaphragmatic disease, you were able to perform surgery laparoscopically in your final case, having previously approached these cases via laparotomy. What changed to enable a more conservative surgical approach?
The normal patient position for laparoscopy is supine, which means the patient is lying on her back on the operating table. The liver blocks the view of the diaphragm as discussed above. The liver also gets in the way of trying to do laparoscopic surgery on the posterior diaphragm, which is what led to the need to resect diaphragmatic disease by laparotomy - with excellent symptomatic results. By turning the patient on her left side ("left lateral decubitus" position) gravity allows the liver to fall away from the right diaphragm and allows relatively easy laparoscopic surgery.

What are the advantages/disadvantages of laparoscopy versus laparotomy for the patient and the surgeon?
Laparoscopy is always preferable to laparotomy due to less surgical pain, better cosmetic results and shorter hospitalization. Laparotomy is not necessarily easier surgery than laparoscopy, although many surgeons may feel more comfortable with laparotomy. The symptomatic relief is excellent with resection of diaphragmatic disease regardless of how it is done. There is a small risk of temporary paralysis of the diaphragm due to injury to the phrenic nerve, although I saw this in only one patient and it seemed to improve over time.

Is all diaphragmatic disease in theory treatable via laparoscopy?
I think it probably is.

If a patient were offered excision via laparotomy, would this be an acceptable strategy, given the current possibilities?
The most important point about surgery is excision of all disease no matter how it is done. Laparotomy is always acceptable if the surgeon will excise all disease and lacks the ability to do the surgery by laparoscopy. There are not a lot of surgeons treating diaphragmatic endometriosis completely by either laparotomy or laparoscopy, and not all practicing gyns know who these top-tier surgeons are. Since symptomatic diaphragmatic endometriosis is always full-thickness, a full-thickness resection of the diaphragm will be necessary. This means that surgery will enter the thoracic cavity, and the diaphragm will need to be closed by sutures at the conclusion of surgery.

What is the prognosis of symptomatic diaphragmatic disease following excision?
100% of patients have excellent relief of symptoms. 95% of patients have complete symptom relief.

How can recurrence best be avoided?
Most 'recurrence' probably represents persistence of disease that was not completely destroyed. Laser vaporization or electrocoagulation are illogical for treating full-thickness diaphragmatic disease and should not be used. Comparing published reports, Nezhat's results with laser vaporization are inferior to excision in regards to symptom relief, which is entirely predictable based on the pathophysiology of the disease and on the fact that laser vaporization has never been studied in any area of the body with respect to how completely disease is destroyed. Medical therapy does not treat endometriosis anywhere in the body, as it is designed only to temporarily reduce symptoms. One possible anatomic consideration is whether diaphragmatic endometriosis might involve more of the thoracic (chest) side of the diaphragm than the abdominal side. Once the obvious disease of the abdominal side of the diaphragm has been removed, the laparoscope can be advanced through the hole in the diaphragm and the thoracic surface of the diaphragm should be inspected for more disease. The inside of the chest wall and lung can also be inspected. I never found disease of the chest wall or lung. From our current knowledge of diaphragmatic endometriosis, there does not appear to be an obvious advantage of performing thoracoscopy (inserting a small diameter scope between the ribs to view the chest cavity) when treating diaphragmatic endometriosis. The exception to this would be for investigation and possible treatment of catamenial pneumothorax when adhesions between a certain area of the lung and the chest wall might indicate the presence of a problem with the lung at that site.

Is diaphragmatic disease a marker of disease elsewhere?
Yes. All the patients with symptomatic diaphragmatic disease I encountered (probably 20 cases in total) had severe pelvic and/or intestinal endometriosis.

What is the recovery like following the excision of diaphragmatic disease?
Recovery depends most on whether the disease is resected by laparotomy vs laparoscopy. Laparotomy results in an incision across the bottom of the right rib margin (like old-fashioned gall bladder removal incisions). This can be extra painful for the first week or two, with noticeably bothersome pain for another month or two. With laparoscopy, the incisions hurt very little after a few days. With either type of procedure, the surgical injury to the diaphragm results in production of fluid (like what is produced in your ankle if you sprain it) for a few days. If this fluid collects in the chest, it can interfere with expansion of the lung, so a small drain should be left in the chest cavity for several days to drain fluid from the chest. A formal chest tube is not needed for draining the chest fluid, a small drain such as a Jackson-Pratt drain inserted at the end of surgery will suffice. Since women undergoing diaphragmatic resection for endometriosis usually also have extensive pelvic and/or intestinal surgery, they often will have a drain to drain the abdominal fluid which is produced for several days after surgery.

Do these patients follow a similar recovery to those who have undergone excision of pelvic disease alone?
All surgery takes 6 - 8 weeks for complete healing to be complete, sometimes longer. Even with surgery in the pelvis and on the diaphragm, everything heals at the same rate, so recovery is pretty similar to those having excision of pelvic disease only. After resection of diaphragmatic endometriosis, the patient will have some chest discomfort and may well have extra fatigue compared to women having pelvic surgery alone. The chest drain tube can be removed in the patient's hospital room after the drainage has almost stopped.

What are the specific risks associated with full-thickness excision of diaphragmatic disease?
The main theoretical risk would be paralysis of the diaphragm due to injury to the phrenic nerve which controls its movement. I am aware of only one patient in my series who may have had this. However, the phrenic nerve is a peripheral nerve, and peripheral nerves can regenerate, and this patient improved over time. Women with diaphragmatic endometriosis have often limited their activities because of pain with deep breathing, so when their pain is relieved after surgery, their breathing and exercise capability improve even though a portion of their diaphragm has been removed.

How common are complications?
The most common complications of any surgery are bleeding, infection, or damage to other organs. The blood vessels supplying the diaphragm are not particularly large and bleeding should not be an issue since surgeons know how to control bleeding in several ways. I never had to transfuse a patient due to bleeding from diaphragmatic resection. I never saw an infection related to diaphragmatic resection. About the only organ that could be damaged would be the lung, but the lung is easily visible through the hole in the diaphragm, and it is easy to avoid it.

Is this type of surgery more risky than excision of disease in other locations?
Diaphragmatic resection for endometriosis is LESS risky than treatment of invasive pelvic and intestinal endometriosis - the blood vessels are smaller, there is only one vital organ in the vicinity (the lung), and invasive disease of the diaphragm doesn't invade anything else, although occasionally there can be some adhesions to the adjacent liver which are easy to treat.

When a patient undergoes surgery to remove diaphragmatic disease, should a thoracic surgeon be present?
Diaphragmatic endometriosis can be resected by a general surgeon or by a gynecologist with experience with the disease. I performed several diaphragmatic resections at laparotomy by myself and those patients had very smooth recoveries. A thoracic surgeon would also be able to treat the disease, but the surgery is not difficult to perform and usually doesn't actually involve surgery within the chest cavity. If catamenial pneumothorax has been documented previously, a thoracic surgeon should be included on the surgical team.

What are the respective roles of the gynecologist and the thoracic surgeon?
The gynecologist should understand that all diaphragmatic endometriosis should be resected and should understand that this will usually require full-thickness resection. A thoracic surgeon may have no experience with the disease and would benefit from guidance by the gynecologist. Thoracic surgeons don't have as much experience operating by laparoscopy, so sometimes a gynecologist may ask a thoracic or general surgeon to be present to observe and assist and to 'bless' the surgery and how it was done.

When large areas of diaphragm need to be excised in order to remove all disease, how are these areas best repaired?
Large areas of diaphragm will need to be removed in virtually all cases of symptomatic disease. These areas can be closed with permanent sutures. Although a general surgeon may be tempted to use some type of mesh to close the holes in the diaphragm, this was never done in my series and we had no problem getting the diaphragm back together again. Mesh problems are common with pelvic surgery and I worry about mesh problems if mesh were used on the diaphragm. Also, if the hole(s) in the diaphragm were just covered with mesh and not sutured together, these holes, although covered by mesh, might interfere with proper healing, re-innervation and functioning of the diaphragm.

Questions by Libby Hopton and answers by Dr. David Redwine