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Chapter 22A - Atlas of Limb Prosthetics: Surgical, Prosthetic, and Rehabilitation Principles Translumbar Amputation (Hemicorporectomy): Surgical Procedures
Lawrence D. Wagman, M.D.
Jose J. Terz, M.D.
PATIENT SELECTION
Ablation of the caudal 50% of the human body has been named by the level of amputation, translumbar amputation (TLA), and by the extent of amputation, hemicorporectomy. Regardless of the nomenclature, this operative procedure is extensive in its loss of structure and function. Fortunately, due to advances in surgical reconstruction, physical and social rehabilitation, prosthetic materials and fitting, and functional aids to the handicapped, the ravages of the operative procedure can be ameliorated. Unlike all other amputations, TLA involves the loss of structures used in functions other than mobility and manipulation. The sphincteric and storage functions of the anus and rectum and urogenital diaphragm and bladder are lost. Sexuality is severely diminished due to loss of both internal and external endocrine and reproductive organs. The extensive known, anticipated, and guaranteed postoperative problems charge the surgeon and the support team with the task of careful patient selection, preoperative patient and family education, and absolute clarity in description of the risks and benefits.
TLA cannot be planned and executed in a short period of time. Patients must be slowly advised of the individual losses they will face and the relative benefit of the operation in relation to the disease process and their symptoms. Patients must be given latitude in deciding on the operation, and it may be anticipated that a patient will cancel or delay the planned TLA. The surgeon and rehabilitation team must be sensitive to this reluctance and respond with further supportive and educational input. Coercion, intimidation, and incomplete discussion of the extent of the operation will foil any attempts at providing optimal patient care and the requisite strong patient-physician relationship.
As a group, patients who become eligible for TLA have a disease process that is recurrent or chronic. The recurrent group is made up of patients with low-grade, nonmetastatic tumors in whom there is an excellent chance for long-term cure. These might include low-grade chondrosarcoma, sacral chordomas, giant-cell tumors, or vascular neoplasms (massive hemangiomas or arteriovenous malformations). Patients with significant spinal cord injury resulting in paraplegia, loss of potency, insensate anal sphincter, chronic urinary tract disease due to a neurogenic bladder, and severe pressure ulcers may rarely be candidates for TLA. Despite the functional losses and significant structural distortion, few patients would consider loss of these cumbersome limbs and dysfunctional structures. The importance of "looking whole" even when the whole is defective is primary. The need for intactness of the body becomes one of the major driving forces in the patient's rehabilitation. The rehabilitation must be structural and functional.
An evaluation of the extent of the primary disease should include an exhaustive search for metastases or proximal local growth. Current diagnosis of the intrathecal extension of sacral tumors includes a magnetic resonance imaging (MRI) study. MRI is sensitive to changes induced by radiation therapy and can differentiate between tumor and radiation changes. The infiltration of the paraspinal muscles by tumor can be identified, as well as soft-tissue masses encroaching on the nerve roots and dural sac. Patients in whom the disease cannot be encompassed are not candidates for translumbar amputation.
SURGICAL TECHNIQUE
The strategy for the surgical portion of the operation can be divided into three sections: soft tissue, bony and neural, and vascular. The latter two are definitive commitments, whereas the former can be undertaken as the preliminary portion of the operation and be used as a diagnostic as well as a therapeutic maneuver. The integrated operative team includes an anesthesiologist, neurosurgeon, orthopaedic surgeon, urologist, reconstructive surgeon, and surgical oncologist. The intraoperative findings will dictate the degree of involvement of each of these specialists. Adequate amounts of blood and blood products or alternatively a system for intraoperative blood loss collection and reinfusion should be prepared. Hemodynamic monitoring with arterial and central venous catheters is secured. Positioning of the patient after intubation will depend on the plans for the individual patient as described in the text.
An incision is outlined and extends anteriorly from the most posterior aspect of the iliac crest, along the inferior edge of the anterior abdominal wall at the level of the inguinal crease along the pubic bone to the pubic symphysis, and in a mirror image pattern on the contralateral side. The muscles of the anterolateral abdominal wall are divided from their bony insertions, and the inferior epigastric artery and vein are divided. In the male, the spermatic cords are left with the specimen. The abdomen is then opened. An exploration can be performed to assess the intra-abdominal extent of the tumor and potential sites of metastases, including the periaortic nodes above the planned level of transection (L3-4), paraspinal soft tissues, and the liver parenchyma. If any suspicious findings are noted, biopsies can be performed before any irreversible steps are taken.
After the resectability of the tumor is confirmed, the anterior flap is reflected superiorly by dividing the balance of the anterior abdominal muscles, and attention can be directed toward division of the intra-abdominal vascular structures and soft tissues. The ureters are identified at or above the level of the common iliac vessels. Consideration of tumor location, previous radiation therapy, and planned urologic reconstruction will dictate the level of ureteral division. Care is taken to preserve the entire length of the ureter with its enveloping blood supply. Because of the level of amputation the majority of the blood supply to the ureters will descend in a caudad direction from the renal pelvis. At the time of ureteral division, large ligaclips or a tie is placed on the proximal portion of the ureter to allow dilatation prior to reconstruction.
The aorta and vena cava are mobilized above their bifurcation and below the renal artery and veins. If necessary the inferior mesenteric artery can be divided. Mobilization of the great vessels will invariably require division of one or two of the lumbar vessels and the right gonadal artery. After complete mobilization, the aorta is cross-clamped by placing a vascular clamp approximated 2 cm cephalad to the planned division site. Communication between anesthesiologist and surgeon is required at this point to ensure precise evaluation of changes in arterial blood pressure, urine output, and central venous or left ventricular end diastolic pressure (pulmonary capillary wedge pressure). Acute hypertensive changes may require stepwise clamping with the addition of peripheral vasodilators (nitroglycerine) and mild volume reduction (diuresis). The aorta is trans-sected sharply and the distal end oversewn. The proximal portion of the aorta is closed with a running 3-0 monofilament vascular suture. The vascular clamp is released one or two clicks and any additional hemostasis secured with interrupted sutures. Rarely, sutures and pledgets may be required due to atherosclerotic changes or injury from previous radiation therapy. The vena cava is clamped and divided in a similar manner. Often, a thinner suture material (4-0 monofilament) can be used for the closure. Communication with the anesthesiologist is critical in anticipating and monitoring the sudden loss of venous return.
With the completion of mobilization and division of the aorta and vena cava, attention is turned to the right and left sides of the retroperitoneum. On the right, the gonadal vein and, on the left, the gonadal artery and vein are the primary remaining retroperitoneal vascular structures to be ligated and divided at the level of the planned muscular transection. The base of the small-bowel mesentery with the right and ileocolic vessels, cecum, and right colon are mobilized cephalad in a fashion similar to a right retroperitoneal lymph node dissection. The use of the right colon and terminal ileum to construct a continent reservoir for the urinary diversion (with loss of the ileocecal valve and the majority of the right colon) makes preservation of maximum colonic length important. Care must be taken in dividing the sigmoid colon at its most distal, viable extent. This is especially important if the inferior mesenteric artery has been ligated at its takeoff from the aorta. The paired structures of the retroperitoneum, including the sympathetic trunk, psoas muscle, and genitofemoral and femoral nerves, are divided. The musculature of the posterior abdominal and lumbar areas is divided at a level selected to preserve the maximum amount of vascularized soft tissue for closure. If any doubt exists regarding the level of tumor infiltration, a biopsy should be performed to ensure that the soft-tissue margin is pathologically negative.
The division of the bony structures (vertebral bodies, transverse processes, and spinous process) and the du-ral sac with the spinal cord can be approached in one of two ways. In patients with neoplastic disease that may extend proximally along the dura or meninges or in cases where preoperative evaluation has suggested possible tumor extension intrathecally above a resectable level, the surgical procedure should begin with a posterior-element laminectomy from approximately T1l to L3. This initial exploration can be extended to include opening of the dura, division of the cauda equina (at the Ll-2 level), and repair of the cephalad dural division. Meticulous hemostasis is essential to prevent an epidural hematoma. The patient can be turned to begin the anterior and intra-abdominal portions of the procedure. In patients whose disease is best approached with a primary anterior approach (those who require abdominal exploration or biopsy of retroperitoneal or anterior paraspinal musculature), the division of the bony and neural elements is the final step in the TLA. When this approach is used, the disk space is identified at the planned level of the TLA. The disk is removed or divided sharply with a knife and the dural sac identified anteriorly. The sac is opened and the neural elements ligated and divided. The final division of the transverse process and spinous process is performed with an osteotome. Significant bleeding can occur at this point from the spinal artery and veins. If not easily controlled, packing with cottonoid sponges can tamponade the vessels and allow for better exposure of these vessels by completing the soft-tissue division. The posterior skin and remaining musculature is rapidly divided. The specimen is removed from the operative field and meticulous hemostasis secured along the dura, in the paravertebral muscles, and along the skin edge. Care should be taken to resect any posterior elements (spinous or transverse processes) or residual vertebral bodies that may cause compression on the posterior flap.
Continent urinary diversion has been used more recently with creation of an Indiana pouch-formation of a detubularized reservoir from the right colon combined with plication of the terminal ileum and submu-cosally tunneled ureters. The result is a 350- to 700-mL continent reservoir that requires catheter drainage approximately every 5 to 6 hours. The stoma is created by using the plicated terminal ileum and is placed through the anterior body wall flap in the mid to upper right quadrant. After initial healing, no ostomy bag is required, and the difficulty in fitting the patient in the bucket prosthesis is reduced.
After adequate mobilization of the distal portion of the colon and re-examination of vascular integrity, an end colostomy is formed in a comfortable position. This will usually be in the central or left upper portion of the anterior abdominal wall flap. Care must be exercised in planning a stoma that will be not compressed by the upper edge of the prosthetic bucket.
The flap closure is performed in layers approximating the well-defined fascia of the anterior abdominal wall to the lumbodorsal fascia with interrupted, permanent suture material. The subcutaneous tissues are closed with interrupted absorbable suture and the skin with metal staples or monofilament suture. The colostomy and urinary pouch stoma can then be matured and all wounds covered with appropriate dressings or drainage bags. A net-type dressing covering the TLA stump helps in securing the dressings in place without placing tape on the skin of the tenuous flaps (Fig 22A-1.).
In cases where large amounts of skin are to be removed, flap reconstruction with myocutaneous or fascial cutaneous flaps can be considered. Occasionally, tissue can be preserved from one of the lower limbs. One such flap utilizes the skin, subcutaneous tissue, and muscle perfused by the femoral artery (Fig 22A-2., Fig 22A-3., Fig 22A-4., and Fig 22A-5.). The use of free flaps has not been attempted but may provide an additional alternative for coverage of the soft-tissue defect and closure of the wound.
COMPLICATIONS
The complications of TLA are primarily related to flap formation, urinary reconstruction, and the extensive surgical procedure, (Table 22A-1.). The anterior flap suffers from distal ischemia due to the division of the inferior epigastric artery and vein. In addition, the closure of the flaps may be performed under tension because of the reduction in the volume of the intra-abdominal space (loss of the false and true pelvis, or approximately 25% to 30% of the volume). The posterior flap is relatively ischemic due to the division of the aorta and associated lumbar vessels above the level of the aortic and caval transection. The division of the posterior musculature and prior treatments (particularly radiation for sacral malignancies and embolization for arteriovenous malformations) also contribute to the tenous vascular supply to this myocutaneous or fascio-cutaneous flap.
In the postoperative period, the patient's positions are limited to supine and lateral ones due to new stoma formation, the need for respiratory support on the ventilator, and hemodynamic monitoring. This increases the shear and compressive pressure on the posterior and lateral aspects of the flap. It is important to remove all posterior bony elements to minimize pressure points on the flap. A variety of specialized beds have been designed to reduce pressure areas and shear effect. The beds are structured as a (1) series of air cells that inflate in a cephalad-caudal and right-to-left sequence or (2) fluidized ceramic microspheres within a monofilament polyester filter sheet. These beds serve primarily to automatically shift the patient's position and prevent pressure, shear, and friction.
An unusual postoperative problem has been hypertension. This occurs during the first postoperative week and often requires a combination of diuretics, central a-adrenergic stimulators, peripheral a- and ß-blockers and angiotensin I-converting enzyme inhibitors. Although this was thought to be due to volume expansion during surgery, even after a return to correct preoperative volume status (adjusted for new body size), the hypertension persists indefinitely.
Problems with the urinary diversion system occur both in the acute and chronic postoperative period. The initial problems are related to urinary leaks from the conduit and site of ureteral implantation. These are treated with diversion and drainage, and usually do not require formal revision. In the chronic phase, problems are related to urinary tract infections, chronic reflux
(prevented by the nonrefluxing ureteral implantation in the Indiana pouch), and metabolic problems related to pouch bicarbonate wasting that result in hyperchlore-mic metabolic acidosis.
POSTOPERATIVE MANAGEMENT
The early postoperative period is marked by redistribution of the large volumes used in the intraoperative replacement of blood and fluid losses. The blood loss may range from 3,000 to 8,500 mL, and replacement with packed red cells, whole blood, and fresh frozen plasma is required. Care is taken to prevent pulmonary overload and renal dysfunction by utilizing volume assessment with central venous or pulmonary artery catheters. Hypertension can be a problem for unknown reasons but is hypothesized to be due to changes in the distribution of the intravascular volume. Following ex-tubation, patients begin a slow re-education to the upright position. They must overcome significant deficits in balance and transfer. The bed is initially equipped with a trapeze device to encourage the patients to look around and strengthen the upper part of their body. The sense of being able to move from side to side and arising from the supine position has psychological benefits. Sitting upright is accomplished by graduating through a series of semirecumbent, sequentially increasing positions. Care must be taken not to put excessive pressure or shear on the stump suture line. Upper-limb strength-training exercises are required to provide adequate power for transfer and locomotion. These exercises all begin in the bed with range of motion, light weights, and use of the trapeze. They are progressed to self-mobilization in the wheelchair and a self-propelled gurney stretcher. Because of pain and positioning, the wheelchair is difficult to maneuver early in the postoperative period. The patients utilize the gurney, which they can operate in a prone position. This is normally their first method for self-mobilization and travel outside their room. Patients are generally able to carry out this activity 1 to 2 months postoperatively. With additional education in transferring, gain of self-confidence, and fitting in the bucket prosthesis, the patients begin to use the wheelchair (standard or electric) as their primary source of mobility (see Fig 22A-6.,A-D).
Nutritional maintenance in the preoperative and early postoperative period can be a difficult problem. Those patients with severe pain or chronic infections may be malnourished when first evaluated. This is due to decreased intake and increased metabolic demands. Intravenous alimentation (either total or supplemental) may be started preoperatively and carried through to the postoperative period. Although the rare patient may begin to take an adequate protein and calorie diet at 7 days postoperatively (those patients who have already had a portion of the procedure performed, i.e., urinary diversion or colostomy formation), the majority of patients are not achieving this nutritional goal until about 3 to 4 weeks postoperatively. The use of centrally administered high glucose and amino acid mixtures with supplemental lipids can bridge the nutritional hiatus during the return of bowel function, healing of intestinal anastomoses (from harvesting the urinary diversion conduit), and resolution of the noninfectious diarrhea that is related to the reduction in bowel length frequently seen in these patients.
Almost all patients undergoing TLA have had pain as a significant component of the disease process. In some, this pain was one of the major motivating factors to undergo the surgery. Postoperative pain can be divided into two categories: incisional and phantom. The former, incisional pain, is related to flap closure and ostomy formation. The sequential use of intravenous narcotics (morphine), potent oral analgesics (oxycodone with acetaminophen [Percocet] or hydromorphone [Di-laudid]) and mild oral analgesics (acetaminophen with codeine) will be adequate for perioperative pain management. Phantom pain is far more complex an entity and may require a variety of pharmacologic (oral and epidural agents), mechanical (changes in position and massage) and electrical stimulatory (TENS, transcutaneous electrical nerve stimulation) modalities for control.
FOLLOW-UP EVALUATION
The primary surgical procedure and the initial recovery require about a 2-month hospitalization. During this period, the patient has had the ablative surgery and care for any initial postoperative problems. Education has been provided regarding the care of the colostomy and may include the use of stomal supplies and techniques of irrigation as well as education regarding the care of the urinary diversion system (either use of the appliances or catheterization of the pouch). The basic techniques for bed-wheelchair transfers have been mastered. The initial bucket and a cosmetic prosthesis for the lower limbs are being fashioned. The steps in preparing and fitting the prostheses are outlined elsewhere (see Chapter 22B). Return to the mainstream requires that the patient be able to move not only within the home environment but also into the community. This may include modifying a car or van with the special apparatus necessary to load the wheelchair and allow the amputee to be securely positioned in the vehicle (see Fig 22A-7.). Of course, all controls must be designed for hand use, including those for acceleration, braking, and direction indicating.
Even with all these features, only a small number of translumbar amputees are able to be completely independent outside of the home. Maneuvering on uneven surfaces and grass, across curbs, and in inclement weather is difficult and at times frightening for these patients. Psychological as well as physical problems are present. Early in the preoperative evaluation and throughout the postoperative convalescent and rehabilitative phases, the patient will need an advocate and support person. A clinical social worker skilled in interpersonal and family dynamics must provide this critical support for the acute problems and during difficult transitions. For younger patients, it is important to counsel them regarding employment options, possibility for further education, and anticipated difficulties in social interactions. Patients in whom the operation was performed for malignant disease must be evaluated for recurrence according to standard methods. Unfortunately, in a significant number, the tumor will recur with a likelihood of incurable metastatic disease.
SUMMARY
TLA is a structurally and functionally feasible ablative procedure. The preoperative preparation must include an extensive search for metastatic disease and discussion with the patient and family of the risks, expected benefits, and long-term results.
The health care team includes nurses, social workers, physical and occupational therapists, a dietician, and physicians. Operative preparation includes adequate blood and blood product availability and coordination of the multispecialty operative team. Early postoperative problems are large fluid volume shifts, flap ischemia, and difficulties with the urinary diversion. Rapid involvement of the patient and family in the rehabilitative process, which includes mobilization, feeding, and socialization, is critical. Long-term goals of driving, education, employment, and interpersonal relations should be discussed and sought. The specter of recurrent disease is present and makes long-term follow-up evaluation essential.
References:
- Ahlering TE, Weinberg AC, Razor B: A comparative study of the ileal conduit, Kock pouch and modified Indiana pouch. J Urol 1989; 142:1193-1196.
- Ahlering TE, Weinberg AC, Razor B: Modified Indiana pouch. J Urol 1990; 145:1-3.
- Aust JB, Page CP: Hemicorporectomy. J of Surg Oncol 1985; 30:226-230.
- Larson DL, Liang MD: The quadriceps musculocutaneous flap: A reliable, sensate flap for the hemipelvectomy defect. Plast Reconstr Surg 1983; 72:347-353.
- Ling D, Lee JKT: Retroperitoneum, in Stark DD, Bradley WG (eds): Magnetic Resonance Imaging. St Louis, Mosby-Year Book, 1983; pp 1156-1163.
- Terz JJ, Schaffner MJ, Goodkin R, et al: Translumbar amputation. Cancer 1990; 65:2668-2675.
Chapter 22A - Atlas of Limb Prosthetics: Surgical, Prosthetic, and Rehabilitation Principles
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