Surgical Irrigation: An Exploration

Surgeons have the freedom to choose the solution used by the operating team to irrigate a patient's wound or incision. The purpose of irrigation is to prevent infection as much as possible during the post-op recovery period, and can often help during surgery when skeletal or tissue debris can impede a surgeon's vision. For the most part, surgeons use an antibacterial solution that consists mostly of saline solution. Saline is simply a homogenous mixture of purified water and NaCl (Salt), and most saline solutions are 90% NaCl.

Beyond saline, which is more commonly used in nasal irrgation or to clean ear piercings, antibiotic additives are added to the average surgical irrigation solution. A common example of an antibiotic additive is Bacitracin, a mixture of cyclicly related polypeptides originally isolated in the 1940s. Bacitracin, much like penicillin, interferes with the dephosphorylation of the C₅₅-isoprenyl pyrophosphate, a molecule that carries the building-blocks of the bacterial cell wall outside of the inner membrane to help prevent infection through the cell wall.

While many studies show that bacitracin and saline solution does lower the rate of infection significantly when used on an open wound, such as a study done in a lab in Turkey with three sets of rats, one of which was treated with bacitracin after an open wound, some treated with 50% bacitracin solution, and one control with pure saline, which revealed 2 out of 13 rats had no infection in the first group and 13 out of 13 did in the control (International Journal of Impotence Research 2000, http://www.ncbi.nlm.nih.gov/pubmed/1852419), infection still remains a rampant post-op hazard.

For this reason, neuro and spine surgeons have experimented with the use of betadine and peroxide in their saline irrigation, despite some studies that show that betadine may be toxic to some groups of cells. A study done in 2009 in Siena, Italy, revealed that when using irrigation in spinal surgery that contained 1/3 H202, 1/3 Betadine and 1/3 Saline, 0 infections came about, a better result than the 7 found when using antibiotic irrigation the prior year (http://www.ncbi.nlm.nih.gov/pubmed/21258810).

Today, increasing numbers of surgeons have begun to use betadine or povidoneiodine in their intrasurgery irrigation. Betadine and Povidoneiodine are widely used antiseptic and disinfectant agents. They can eradicate most pathogens, included MRSA, and no bacterial resistance has been reported. However, it has been thought to be toxic to osteoblasts and fibroblasts, possibly retarding bone and wound healing. But, because of iodine solution's success in preventing infection, this concept is now challenged.

Burkitt's Lymphoma and HIV - Pre-Op Consult, Operation, and Follow Up

Chemotherapy typically follows after radiosurgery to treat small cancerous tumors in the human brain. However, when the tumors are the result of Burkitt's Lymphoma, the disease is exponentially more serious and requires many more treatments. Burkitt's Lymphoma is a fast-growing cancer of the lymphatic system, specifically B-Cells (classifying it as a type of leukemia). All types of Burkitt's are associated with HIV and immunodeficiency. In fact, 90% of AIDS cases are complicated by an onset of Burkitt's.

In the types of Burkitt's encountered in North America, the cancer usually starts in the belly area (abdomen). The disease can also start in the ovaries, testes, brain, and spinal fluid. Swelling of the lymph nodes is the primary symptom of the condition.

http://lymphoma.about.com/od/nonhodgkinlymphoma/p/burkitts.htm

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When diagnosed early, chemo can be extremely effective as a solution for Burkitt's ironically because of its naturally fast progression (the chemo progresses quickly when the cancer grows quickly). Patients treated with HAART  (Highly Active Antiretroviral Therapy) for HIV, have a typically better chance for survival with Burkitt's lymphoma as well. These patients are basically being treated with a drug cocktail of sorts since HAART is defined as treatment with at least three active anti-retroviral medications (ARV’s).

The chemotherapy treatments are administered through a ventricular cathoder that is surgically inserted. It is a short surgery and an easy insertion into the third ventricle of the brain once the tumor is located via MRI scan. Surgeons implant what is called an Ommaya Resevoir for easy drug administration:

http://www.cw.bc.ca/library/pamphlets/search_view.asp?keyword=373

If the patient, however, has already developed carcinomatosis and has widespread cancerous lesions throught the body (as is often the result of lymphoma), the treatments are less effective.

How Shunts Work: An Exploration

As previously discussed, shunts are valves implanted into the brain through a craniotomy to relieve intracranial pressure by means of pumping out excess CSF. They are especially useful, for those reasons, when treating hydrocephalus. The valve is usually planted outside the skull, but underneath the skin, somewhere behind the patient's ear, and the tube that relieves the brain of the fluid is threaded underneath the patient's skin down to the stomach where the CSF can then be best absorbed.

Shunts look like the following (as seen in a previous article): 

 

Shunts have five pressure level settings: .5, 1, 1.5, 2, and 2.5. The various settings allow the surgeon to adjust the degree of CSF drainage after insertion without having to re-operate on the patient to place a new shunt with a new higher or lower pressure valve. The higher the setting, the less CSF is drained from the ventricles. Rather, shunts, or the rotary spring mechanism within them, can be adjusted by the use of a magnet since the valve itself is programmed magnetically. Whenever patients undergo an MRI scan, or anything of the sort, the shunt must be reprogrammed by the original surgeon since the magnetic field generated by the MRI would disrupt the shunt's original settings.

http://www.neurosurgery.pitt.edu/cerebrovascular/endovascular/treatments/nph.html

Possible complications to shunt insertion include infection (since the shunt is a foreign body), shunt blockage, chiari malformation, over drainage and hematomas (brain bleeds). Shunt removal is a very rare procedure. Most patients that require shunts need them for the entirety of their lives, even children. CSF over production does not repair itself, after all.

Radiation Necrosis: An Exploration

Dural-based lesions can often be the result of radiation necrosis, especially in patients who have been treated with radio surgery on multiple occasions. Radiation necrosis can occur when radiotherapy is used to treat primary CNS (Central Nervous System) tumors, metastatic disease, or head and neck malignancies. Lesions that are caused by radiation necrosis usually occur at the original tumor site.

Radiosurgery is a medical procedure that allows surgeons to treat both malignant and benign tumors in a non-invasive manner. Highly focused beams of ionizing radiation are directed at lesions by means of an "emission head" connected to a linear accelerator that dispenses the radiation.

Emission Head: http://www.medphys.ucl.ac.uk/research/acadradphys/researchactivities/prs.htm

Linear Accelerator: http://en.wikipedia.org/wiki/File:Clinac.jpg

A solution, or at least an aid in preventing or slowing the progression of radiation necrosis is the administration of steroids. Steroids reduce intracranial pressure significantly and prevent neurological deterioration by keeping the brain active. Necrosis is a common cause for CSF leakage as well, and the introduction of steroids to relieve intracranial pressure would greatly reduce the risk of leakage.

NPH - Normal Pressure Hydrocephalus: An Exploration

A new patient came in the other day referred by her neurologist. An elderly woman, with her husband, began describing her medical history by recalling several seizure episodes and, more recently, her many falling episodes, most of which sent her straight to the emergency room. Unfortunately, neither she nor her husband could remember all the details pertaining to her accidents, but many of the doctors she had seen in the past had deduced that her seizures and her falls were not connected. We, however, weren't convinced.  Drop seizures, the result of the neurological disruption in the brain causing a seizure spreading throughout the entirety of the brain and therefore making one immobile, could have explained the patient's falls, especially since the patient could not remember most of the circumstances in which she fell. Although she had an EEG done, no decisive conclusions had been done concerning the relationship between her seizing and her falls.

Most recently, she had undergone a spinal tap to try to help her restore her balance and a good flow of CSF. A spinal tap, or lumbar puncture, can serve two purposes: collecting a sample of CSF to test for biochemical or microbiological analysis, or as a therapy to relieve increased intracranial pressure.

http://health.allrefer.com/pictures-images/lumbar-puncture-spinal-tap.html

 

 

 

 

The procedure is done by administering a local anesthetic to the lower back while the patient remains in a fetal position. A needle is inserted past the spinal dura to gain access to the spinal fluid. The patient is then monitored for headaches afterwords.

Our patient reported that although her balance did not improve, she felt more alert and more "like herself" after the lumbar puncture. She was worried that she had developed NPH, Normal Pressure Hydrocephalus, a condition that develops slowly over time and arises mostly in the elderly. With Normal Pressure Hydrocephalus, the drainage of CSF in the brain ventricles is blocked, and the swelling of the ventricles can cause serious brain damage.

The "triad" of symptoms that represent the harboring of NPH are increased dementia (increased mental incapacitation), urinary incontinence, and walking with an abnormally wide gait. Our patient had trouble walking because of her bad knee and arthritis, did not complain of bladder problems, and seemed to be fairly mentally healthy. Since her symptoms her so inconclusive, we urged her to hesitate on asking for surgery and to rethink the diagnosis. The solution for NPH is to insert a shunt to relieve CSF pressure and thereby create the effects of the lumbar spine puncture for an indefinite amount of time. However, the risks associated with shunt insertion, especially in an elderly patient, include subdural hematoma and massive intracranial bleeding. Hopefully her falling issues were not brain-related and simply had to do with the arthritis in her knees.

Inserting a shunt in an adult:

http://hydrocephalus.yolasite.com/hydrocephalus.php

Choroid Plexus: The Red Cauliflower Turns White: Post-Op Report

A post-op patient that had a shunt inserted to relieve and aid in CSF flow came in complaining of pain and incessant headaches. Looking at her cat scan, we noted how one can see the shunt in every photographic cut as a white oval representative of the shunt drain line. However, other white spots were also visible around the third ventricle.

http://www.psyweb.com/Brain/brainv0.jsp

The whiteness showing on the cat scan was the result of calcification of the choroid plexus that surrounds both the third and fourth ventricles in the brain and is responsible for CSF secretion. Apparently, in its normal state, it very much represents red cauliflower:

http://www.psyweb.com/Brain/brainv23.jsp

The ventricle complex in the brain is wholly responsible for CSF fluid and the insertion of CSF into the bloodstream via villi at the base of the Fourth Ventricle. When the Choroid Plexus calcifies, it is most commonly the result of age but can also be the result of neurofibromatosis or other serious mental disease. In our patient, a combination of age and neurofibromatosis is the understood reasoning for the calcification. Because of the patient's possible harboring of neurofibromatosis, she is closely monitored by the staff and is constantly getting new screenings.

The original purpose of her surgery, the shunt, was the result of her showing symptoms of excessive pressure within her brain which caused CSF leaks on both sides of her brain. The calcified choroid plexus looks like the below:

From Endonasal to Supra-Orbital Eyebrow Craniotomy: Post-Op Report

In just the past sixth months, neurosurgeons have begun to make the switch on a massive scale to conducting tumor-removal by making a supra-orbital incisions rather than going in through the nose. Studies have shown that there is an increased probability of CSF leaks as a result of endonasal procedures, and supra-orbital eyebrow incisions allow for a cleaner way to pull out a tumor in the frontal lobe. The main advantage of going in through the eyebrow, however, is that there is little to no retraction of the frontal lobe involved, unlike in endonasal surgeries.

The risks associated with brain retraction, especially in the frontal lobe, include general brain tissue damage, loss of vision, thrashing incapacitating headaches, and worst of all, perioperative morbidity.

This approach is performed through an incision in the eyebrow and the consequent removal of a tiny piece of skull.  It differs from the traditional fronto-temporal craniotomies in that it involves much less bone removal and, as mentioned before, minimal to no brain retraction as shown:

http://www.mayfieldclinic.com/PE-Pit.htm

 

The patient, who had the operation three months earlier, received chemotherapy just after the surgery. Her chemo lasted for about two months. Cosmetically, the eyebrow looks completely normal. There is a little bit of swelling around the eye that increases and decreases periodically but should completely heal after a year or so. Nevertheless, the damage to the frontal lobe did reduce motion to the side of the face operated on. On that side, the patient could not lift her eyebrow as far as she could on the other. Apparently it is possible for that nerve injury to completely heal, but full recovery of that nerve is not guaranteed. Other than that, however, only good news was buzzing through the clinic. The tumor was gone, the scans showed no signs of regrowth, and the frontal lobe seemed completely healthy as it adopted to the removal of the tumor and grew to fill the cavity.

Chiari Malformation Decompression Surgery: Post-Op Report

After many months of hardship, today's first patient came bounding into the clinic full of joy, thanks, and some minor neck pain. Her surgery, which had taken place three months earlier, left her unable to work and on a drug cocktail of pain medications. Her symptoms included massive headaches which rendered her immobile. She described them as "crushing". Her diagnosis was a Chiari Malformation, a condition where the cerebellar tonsils are displaced out of the skull area into the spinal area, causing compression of brain tissue and disruption of CSF flow.

http://www.mayoclinic.org/chiari-malformation/enlargeimage4476.html

The goal of the decompression surgery is to remove small sections of the bone at the back of the skull by the cerebellum to relieve pressure between the cerebellum and the brain stem and thereby allow a fluid path for CSF.

In this particular case, a patch graft, or dural graft, was instituted in place of the removed bone. There are several choices for what to use as a patch graft:  tissue taken from the patient's own body, bovine pericardium, dura taken from a cadaver, or a synthetic material.  Unfortunately, there is no clear agreement among surgeons on which material is best suited for the job. In this case, a synthetic material had been used. Today, increasing numbers of doctors are questioning the use of patch grafts in this surgery. Not only does the insertion of the graft increase the risk of infection, but also threatens the flow of CSF. In children, studies have shown that 80-85% of cases without the use of a patch graft are successful. However, there are no studies on the effectiveness of that method in adults.

During post-op, we began by taking the patient's vitals. Although her blood pressure was high, she seemed fairly normal. She complained, however, of intermittent neck pain and a lack of mobility in the neck. She has been going to physical therapy to increase that mobility for the past two weeks, and is now driving again because she can turn enough to see the rear-view mirrors. She has apparently shown significant improvement, so much, in fact, that she has taken herself off of morphine and other strong pain medications. She is preparing to return to work as soon as the opportunity presents itself.

A final comparison between a healthy chiari and a malformation that requires the decompression surgery:

http://www.healthline.com/galeimage?contentId=gech_0001_0001_0_00121&id=gech_0001_0001_0_img0056