The
retroperitoneal space
Pus or blood in the retroperitoneal space tends
to track to the corresponding iliac fossa. If a retroperitoneal abscess develops,
it should be evacuated by the nearest route through the abdominal wall, avoiding
opening the peritoneum. Should the retroperitoneal collection be found at
laparotomy, it must be drained by a counter-incision in the flank. Pus
frequently develops from a renal or spinal source and is sometimes tuberculous
(‘cold abscess’): tracking can develop alongside the psoas muscle and appear
in the groin, where it must be distinguished from other swellings (e.g. hernia,
Chapter 62). Retroperitoneal haematoma may be caused by fractured spine, a
leaking abdominal aneurysm, acute pancreatitis or a ruptured kidney.
Retroperitoneal
cyst
A cyst developing in the retroperitoneal space
often attains very large dimensions, and has at first to be distinguished from a
hydronephrosis. Even after the latter condition has been eliminated by scanning
or orography, a retroperitoneal cyst can seldom be diagnosed with certainty from
a retroperitoneal tumour until displayed at operation. The cyst may be
unilocular or multilocular. Many of these cysts are believed to be derived from
a remnant of the Wolffian duct, in which case they are filled with clear fluid.
Others are teratomatous and are filled with sebaceous material.
Excision
of these and other retroperitoneal swellings is best performed through a
transperitoneal incision.
Idiopathic
retroperitoneal fibrosis
This is one of a group of fibromatoses (others
being Dupuytren’s contracture and Peyronies disease). Most cases are
idiopathic, hut many causes are known (Table 56.9). Familial cases are
known, involving mediastinal fibrosis, sclerosing cholangitis, Riedel’s
thyroiditis and orbital pseudotumour. An autoimmune link has not been
demonstrated. Extensive collagen deposition surrounds the ureters, mostly at the
level
Primary
retroperitoneal neoplasms arising from connective tissues
Retroperitoneal lipoma, in the first instance,
is usually mistaken for a hydronephrosis, a diagnosis which is ruled out by
ultrasonography, CT scan or orography. Women are more often affected. These
swellings sometimes reach an immense size. A retroperitoneal lipoma sometimes
undergoes myxomatous degeneration, a complication which does not occur in a
lipoma in any other part of the body. Moreover, a retroperitoneal lipoma is
often malignant (liposarcoma) (Fig. 56.16) and may increase rapidly in size.
Retroperitoneal
sarcoma presents signs similar to a retroperitoneal lipoma. The patient may seek
advice on account of a swelling or because of indefinite abdominal pain. On
other occasions the tumour, by pressure
on the colon, causes
symptoms of subacute
intestinal obstruction. On examination a smooth fixed mass, which is not tender,
is palpated. The most probable original diagnosis is that of a neoplasm of the
kidney .This is ruled out by scanning or orography. The
ureter, however, is liable to become displaced by the tumour. Exploratory
laparotomy should be performed and when possible the tumour is removed. Often it
is found widely disseminated in the retroperitoneal space, rendering complete
removal impossible, in which case a portion is excised for microscopy. Even when
excised at a comparatively early stage, recurrence always takes place, and these
rumours must he looked upon as being necessarily fatal. Radiotherapy sometimes
keeps recurrences in abeyance for a time.
Removal
of a retroperitoneal cyst or neoplasm. After the anterior abdominal wall has
been opened and the diagnosis of a retroperitoneal tumour has been confirmed,
the incision is extended as necessary. The small intestine is packed away in the
upper abdomen or exteriorised and the caecum and the sigmoid colon are relegated
to their respective fossae. The posterior peritoneum is then incised throughout
its length over the area to be exposed, the incision being parallel to the left
border of the aorta. The peritoneum is dissected from the tumour which is
removed as completely as possible.