Introduction
Hemicorporectomy or translumbar amputation is probably the most mutilating operation ever to be described in surgical literature. The procedure involves removal of the bony pelvis, both lower limbs, the external genitalia, the bladder, rectum and anus. Necessary life functions are maintained in the upper torso. The concept of hemicorporectomy was first proposed by Professor Frederick Kredel in 1951 when he proposed the concept of a “halfectomy” as an alternative to pelvic exenteration for locally advanced malignancy in the pelvis (1). Although he never performed the procedure on a live patient, he did demonstrate the procedure on cadaver specimens and recommended that the amputation be performed in two stages.

The first hemicorporectomy was performed by Kennedy in 1960 (2). The procedure was completed in a single stage in a 74 year old man with locally invasive rectal cancer. The patient died of pulmonary oedema 10 days post-operatively. The following year, Aust performed the first successful operation on a 29 year old paraplegic with malignancy arising in a decubitus ulcer (3). The procedure was performed in two stages and the patient survived for 19 years, before finally succumbing to pulmonary oedema.

The third reported case was described by Yancey et al in 1963 (4). Their patient had locally invasive cervical cancer and died of pulmonary oedema 4 days post-operatively.

Since then, the largest series of cases have been the series of 10 cases from Memorial Hospital in New York reported by Miller, and the 6 cases reported by Aust (5,6). The total number of hemicorporectomies which have been reported in the literature to date is 44 (7).

Indications, results and ethical considerations
Hemicorporectomy has been performed for a variety of indications including locally invasive pelvic cancer without metastatic spread, benign spinal tumours, intractable decubitus ulcers with malignant change, paraplegia in association with intractable pelvic osteomyelitis and decubitus ulceration and crushing trauma to the pelvis.

To perform the procedure on a paraplegic patient with intractable ulceration and osteomyelitis about the pelvis with or without malignant change in the ulcers or sinus tracts would seem reasonable in occasional cases. Eighteen such procedures have been described with 6 deaths. Bowel and bladder function are conveniently diverted, and chronic foul smelling discharge and recurrent systemic infection from the pelvis are eliminated.

The issue of whethe or not to offer the procedure as a last resort to a patient with locally advanced pelvic malignancy is much more difficult to address. Of the 24 hemicorporectomies performed up to 1988 for malignancy, 16 have died (8). Seven deaths were due to recurrent or metastatic disease. Eight procedures have been performed for primary bone tumours. These included 5 pelvic chondrosarcomas, 1 pelvic osteosarcoma and 1 giant cell tumour of the sacrum. Of these, only 3 have become long term survivors (2 pelvic chondrosarcomas and one giant cell tumour of the sacrum).

Many surgeons are not prepared to offer their patient a hemicorporectomy under any condition, arguing that the procedure pushes the frontiers of surgery beyond what can be considered reasonable. There is little doubt that given the high mortality following this procedure, especially when performed for visceral malignancy, the indications for its use should be very restrictive. In this regard, it should be noted that 8 of the 44 reported cases to date died within one month of surgery, a peri-operative mortality rate of 18.2% (7).

The patients must have a strong desire to live and must be in good overall physical condition in order to have a reasonable prospect of surviving the procedure. If performed for malignancy, careful pre-operative staging is essential, although this cannot outrule the presence of microscopic metastases. The available survival figures for the procedure must be put to the patient in an objective way so that he or she is equipped with the necessary information to make the most daunting decision of their lives. Given the high mortality from recurrent or metastatic disease following hemicorporectomy for visceral or bone malignancy, it is likely that many patients will choose not to proceed with the operation for this particular indication. Psychological councelling should be regarded as an essential component of the pre-operative work-up. There is a strong case for extending this councelling to the patient’s family and to the hospital personnel who must care for the patient (9).

Operative Procedure
The operation has been most often performed in a single stage, though current recommendations favour two stages, with a gap of about two weeks between first and second stages (7,10). At the first stage, a colostomy and an ileal conduit are created to defunction the rectum and bladder. The location and extent of the malignancy are carefully assessed to confirm that it can be completely resected by hemicorporectomy.

At the second stage the common iliac vessels, the vena cava, lumbar spine, dura and cauda equina are transected and the anterior and posterior skin flaps are approximated.

Hemicorporectomy results in a reduction of body weight by about 50%. The reduction in total vascular area reduces the ability to compensate for changes in circulating blood volume. Small losses may produce shock and intravenous transfusions can easily produce pulmonary oedema. The loss of normal abdominal wall function results in a reduction of lung vital capacity and functional residual capacity and a ventilation-perfusion mismatch with tidal volume diverted more to the lung apices.

Rehabilitation
Rehabilitation centres around the development of a total contact bucket prosthesis which permits an upright sitting posture in a wheelchair and releases the upper limbs for other functions (11). The prosthesis is adjusted to accomodate the stoma sites and to reduce pressure on the terminal lumbar spine. Discomfort from heat limits use of the bucket for some patients.

Upper limb strengthening, vocational training, psychological councelling, sex hormone replacement, education and dietary advice to avoid obesity are all further aspects of what is a lengthy process of readjustment. Patients must, in addition, learn the importance of lifelong careful fluid balance, given the reduced ability of the autonomic system to autoregulate circulating blood volume.

Conclusions
The survival statistics following hemicorporectomy are approximately 70% for benign indications, 50% for trauma, and 30% for malignant conditions. The operation is a technical reality and low peri-operative mortality rates are attainable with better understanding of the changes that occur in circulating blood volumes and improved anaesthesia. The procedure may improve the quality of life in some patients with paraplegia, intractable pelvic sepsis or some otherwise inoperable benign tumours of the sacrum or lower lumbar spine. In malignant disease confined to the pelvis, the surgeon should firstly ensure that the operation can definitely remove all of the primary tumour, that the staging studies are negative, and that the age and general condition of the patient are such that they could withstand the procedure. In appropriate cases the option of hemicorporectomy can then be put to the patient. He or she must understand the magnitude of the undertaking and that the chance of success is of the order of 30%. Some patients will accept these odds while many will choose not to proceed. This unenviable decision must rest with the patient and his or her family.

Case Report
A 32 year old female presented with a three month history of right hip pain which was exacerbated by weight-bearing but was also present at night. She had no documented weight loss or other systemic symptoms. Her past medical history was unremarkable apart from a distal femoral osteotomy to correct an angular deformity at the age of 12 years. She was told at that stage that she had a bony abnormality, the exact nature of which she did not recall.

Physical examination was unremarkable apart from a slight reduction in hip movements and a leg length discrepancy of 1.5 centimetres. Plain radiographs of the pelvis revealed an extensive tumour with chondroid features involving the peri-acetabular bone (Figure 1). In addition, there was evidence of multiple chondroid lesions throughout the pelvis and in both femora.

A diagnosis of grade II/IV chondrosarcoma with a backround of Ollier’s disease was confirmed by biopsy. Extensive intrapelvic involvement was confirmed with cross-sectional imaging and precluded limb salvage (Figure 2). The patient underwent a posterior flap hemipelvectomy (Figure 3).

Pathological assessment of the resection specimen revealed that the margins were negative for the index tumour but that there were multiple enchondromata with in situ chondrosarcoma at the bony resection margins and in the resected femur.

This young lady has made an excellent recovery from her amputation but is at very high risk of developing a second chondrosarcoma, this time in the remaining hemipelvis. This may well necessitate resection of the remaining hemipelvis, with or without the sacrum. The net result will be effectively a hemicorporectomy and seating difficulties will probably make faecal and urinary diversion necessary.

References
1. Kredel FE. Discussion of Bricker et al. Surgery 30:76-94, 1951.
2. Kennedy DS, Miller EB, McLean DC, Perlis MS, Dion RM, Horvitz VS. Lumbar amputation or hemicorporectomy for advanced malignancy of the lower half of the body. Surgery 48:357-365, 1960.
3. Aust JB, Absolon KB. A successful lumbosacral amputation, hemicorporectomy. Surgery 52:756-759, 1962.
4. Yancey AG, Ryan HG, Blasingame JR. An experience with hemicorporectomy. J Nat Med Assn 52(4):323-325, 1963.
5. Miller TR. Translumbar amputation (hemicorporectomy). Prog Clin Cancer, VIII:227-236, 1982.
6. Aust JB, Page CP. Hemicorporectomy. J Surg Oncol 30:226-230, 1985.
7. MacKenzie AR. Translumbar amputation: the longest survivor- a case update. Mount Sinai J Med 62(4):305-307, 1995.
8. Ferrara BE. Hemicorporectomy: A Collective Review. J Surg Oncol 45:270-278, 1990.
9. Raven KA, et al. Hemicorporectomy: a nursing challenge. Orthopaedic Nursing 11(2):73-78, 1992.
10. Stelly TC, et al. Hemicorporectomy. Clin Anat 8(2):116-123, 1995.
11. Smith J, Tuel SM, Meythaler JM, Cross LL, Schuch JS. Prosthetic Management of Hemicorporectomy Patients: New Approaches. Arch Phys Med Rehab 73:493-497, 1992.