Frozen Pelvis is the most extensive form of advanced endometriosis, encompassing the most ultimate forms of deeply infiltrative endometriosis (DIE). This aggressive disease form is inclusive of all extreme endometriosis presentations plus unusual deep infiltrative attachments to outer limits of pelvic ligaments, nerves, and muscle tissues. It can be partial or total frozen pelvis. Frozen pelvis is synonymous with "End Stage Endometriosis" or "Terminal Endometriosis" in the pelvis.
Why use the term Frozen Pelvis?
When Frozen pelvis occurs, deep fibrotic nodules and deeply infiltrative endometriosis replace pelvic soft tissues with high-density fibrosis. Pelvic organs soon become firmly fixed to pelvic bones, making them immobile or “frozen,” comparable to the way ice feels.
Endometrial tissue can implant and invade any tissue of the body, and it does so most frequently in the peritoneal cavity of the pelvis. The peritoneum is the thin membrane that covers the uterus, ovaries, bladder, ureters, pelvic sidewalls and bowel. Endometrial implants are a tissue similar to the tissue that lines the inside of the uterus and is therefore affected by and subjected to a similar reaction to estrogen and progesterone fluctuations, which is to bleed. In other words, mini-menstruations occur at these implantation sites upon hormonal changes that normally cause a woman to have a period. Unlike a period, however, the menstrual blood shed from these lesions becomes trapped in the peritoneal lining. The immune system then undergoes “fights” to clear this debris that results from menstrual shedding of the lesions. The struggle that results is inflammation at the cellular level. Gradually, increased scarring, also known as adhesions, takes place. These adhesions can “glue” internal organs together, wrap around organs, form web-like structures from organ to organ, or attach to the lining of the abdomen called the peritoneum. When a surgeon visualizes the peritoneal cavity and sees adhesions stretching from the ovary to the tubes, the pelvic sidewalls, and the Cul de sac, this may just be the tip of a more serious problem. These adhesions may extend to deeper tissues, involving the nerves, lymph nodes, and/or muscle layers of organs. After the adhesions dig deeper, they harden soft tissues and organs in the pelvis, and what started as an early peritoneal implant becomes a total rock-like tissue due to fibrosis.
Frozen pelvis is different than Stage 4 Endometriosis Disease and Stage 4 Adhesions. While most stages of endometriosis are based on a view of the pelvis during surgery with laparoscopy, a pelvic examination in the office can easily diagnose frozen pelvis by an experienced endometriosis surgeon. In other words, while frozen pelvis is a term more used in an initial clinical setting, stage 4 endometriosis can only be formally diagnosed after surgical treatment.
How can a doctor identify frozen pelvis upon examination?
During a pelvic examination, the doctor feels for a firmly fixed uterus. Sometimes the tissues that are frozen in fibrosis involve nerves and blood vessels both in the front and back of the uterus with no mobility at all. No wonder it is called the called the frozen pelvis! As the doctor performs a vaginal examination, a patient with frozen pelvis can feel extreme pain since the pelvic organs have lost all of their flexibility. This process causes what we call a “frozen pelvis” as the organs no longer move freely or easily within the normal confines of their organic structures. This, in turn, causes pain and discomfort due to the nature of the adhesions pulling on other organs. Usual functions such as a bowel movement, emptying the bladder, menstruation, and sex are extremely painful due to the restrictive nature of scarring and altered anatomy. Bowel obstruction, kidney swelling (hydronephrosis), ureter swelling (hydroureter), bladder dysfunction and the involvement of pelvic nerves are frequently due to partial or incomplete frozen pelvis.
What are the Symptoms of Frozen Pelvis due to Endometriosis?
Severe leg pain can be experienced during and around the times of the period, and pain radiating on the course of sciatic and pudendal nerves is common. Patients with frozen pelvis sometimes cannot cross their legs due to deep tissue infiltrated with endometriosis at the pelvic sidewall or cannot sit due to tailbone involvement. Most patients with frozen pelvis complain of severe changes in bowel habits possibly caused by obstruction, including constipation with episodes of diarrhea, painful bowel movements, and a gassy and bloated feeling. Patients also experience frequent urination (even at night), difficulty holding urine due to decreased bladder capacity and flank pain caused by an obstructed and dilated ureter. These are all very well known and recognized symptoms. Most patients at this stage of endometriosis have also stopped having sexual intercourse because of the disease involvement in the upper part of the vagina. This causes sex to become incredibly painful during and around the time of the period. It is also common for pain after sex to continue for several days. Most of these symptoms present all together in frozen pelvis cases.
How is Frozen Pelvis Diagnosed?
Pelvic examination in the office must be immediately followed again with an endovaginal sonogram while the patient is on the examining table. The purpose of an endovaginal sonogram is to rule out the involvement of the uterus or presence of an endometrioma and confirm findings of bimanual examination. Due to the fact that pelvic examination is extremely painful, the doctor performs a very gentle evaluation at this stage. A recto-vaginal examination is the last part of the evaluation to check for nodules in the rectum and upper vagina. After a thorough examination, the next step is to obtain an MRI of the pelvis with contrast to see the depth of involvement and status of the kidney and its outlets, the ureters and the bladder.
Who Should Perform Surgery for Frozen Pelvis due to Endometriosis?
For those who are interested in understanding the surgery for frozen pelvis, it is important to visualize that the procedure is performed using minimally invasive techniques, also known as advanced laparoscopy. All team members are very experienced surgeons who have mastered their specialty. They all perform their part in the surgery. The urologist performs the cystoscopy and stent application into the ureters. As you can see in the top figure, the entire procedure is performed through tiny instruments going through small incisions with the image of the surgery transmitted over to a high definition video screen. This screen is larger than the actual operative field and allows additional zooming of the camera. This allows the endometriosis excision surgeon to perform excision with the ultimate precision to remove endometriosis scar tissue. In addition to experience with the disease, the skill of the lead surgeon and his or her hand and eye coordination and perseverance has a direct role in the precise and complete excision of the deep nodules. Needless to say, a surgeon must flawlessly suture both extracorporeally and intracorporeally with precision and speed. A surgeon who possesses these qualities will certainly affect the positive outcome. An expert endometriosis surgeon with experience and skill is imperative in order to treat this extreme condition of frozen pelvis. It is not possible to deal with frozen pelvis without a team leader who is an expert endometriosis excision surgeon. This team also has a urologist, colorectal surgeon and vascular surgeon on call, all of who are advanced laparoscopic pelvic surgeons as well.
How complex is Surgery for Frozen Pelvis due to Endometriosis?
Frozen pelvis surgery may last up 6 hours and mostly involves wide excision of the nodular and infiltrative endometriosis involving the bowel, rectum, and sigmoid colon. Bowel resection, discoid excision, and shaving of lesions with nodulectomy are all possible surgical procedures that may be needed. The bladder, the ureters on both sides, and the parametrium of the vaginal walls are always affected in the frozen pelvis, and thus surgery will involve these anatomical locations.
Our Approach to Frozen Pelvis Surgery Performed?
Surgery may be performed by laparotomy (open abdomen), or minimally invasive surgery, also known as laparoscopic surgery. Rather than a large skin incision over the bikini line or from the bellybutton to the pubic hair, our preference as always is the laparoscopic approach where very small, almost invisible incisions are made. Altogether there are only four incisions, and most of them are only one-fifth of an inch (5 mm). If we added together each length of these tiny incisions the total length would be 2.5 centimeters (exactly one inch)! With thorough knowledge and experience with pelvic anatomy, the surgeon advances from surrounding healthy tissue to contain and encircle the fibrotic tissue. When the ureters are safely located, open anatomic spaces around the bladder and around the bowels are used to advance to deeper tissues. Eventually, removal of the disease involves partial removal of the rectum, bladder, ureter and significant volumes of nodular fibrotic tissue attached firmly to muscle, fascia, ligaments, arteries, veins and lastly, nerves. The ultimate principles of microsurgical techniques need to be utilized due to proximity and involvement of the ureters and nerves, particularly the ischial nerve and parametrial retroperitoneal deep tissues, which are all key for nerve function.
As it is now known, frozen pelvis is one of the most extreme cases of endometriosis. Because it is a rare occurrence and the endometriosis scarring is so extensive, many physicians have trouble treating frozen pelvis due to endometriosis. We have learned in these cases, it is crucial to listen to all the complaints and symptoms a patient may present, as these can be key indicators as to where endometriosis scar tissue can lie. As long and intensive as frozen pelvis surgery may be, we stress the importance of removing as much endometriosis scar tissue as possible. Frozen pelvis can cause a great deal of pain in a patient’s day to day life, but there is no reason that you should be in this battle alone.