on 28-Sep-2021 (Tue)

Nephrotic syndrome is characterized by: • hypoalbuminaemia • >3.5 g proteinuria/day • dyslipidaemia • salt and water retention, leading to oedema.

Loss of urinary protein (largely albumin) of the order of 3.5 g or more daily in an adult may lead to hypoalbuminaemia.

the normal liver can synthesize albumin at a rate of 10–12 g daily. How, then, does a daily urinary protein loss of 3.5 g result in hypoalbuminaemia? This can be partly explained by increased catabolism of reabsorbed protein, largely albumin, in the proximal tubules, even though the rate of albumin synthesis is increased.

Proteinuria occurs partly because structural damage to the glomeru- lar barrier (podocytes, basement membrane, fenestrated endothelium and endothelial charge) allows the passage of more and larger mol- ecules.

This is a consequence of increased synthesis of lipoproteins (such as apolipoprotein B, C- III lipoprotein (a)), as a direct consequence of a low plasma albumin.

When a tumour appears to be locally advanced (i.e. invading a neighbouring structure or threatening to breach the circumferential resection margin), the use of neoadjuvant (preoperative) radiotherapy or chemoradiotherapy is usually considered. Long-course chemoradiotherapy is given as 5 fractions of radiotherapy combined with chemotherapy over a 6-week period. The aim is to down-stage the cancer and increase the chances of a complete resection with clear onco- logical margins. Alternatively, preoperative ‘short-course’ (5 days) radiotherapy can be used if the resection margins are not threatened but the cancer is still at high risk for local recurrence (e.g. peri-rectal lymph node involvement).

If there is no evidence of residual cancer on clinical examination, biopsy or radiological imaging, patients are offered intense surveillance in the hope that they may have been cured of the disease and spared the morbidity of resectional surgery.

There is also growing enthusiasm for ‘organ-preserving’ surgical techniques in early T1 and even T2 cancers with good prognostic features. This usually involves full-thick- ness excision of the cancer using TEMS (Figure 73.18). Alternative ‘organ-preserving’ techniques involve the use of brachytherapy and contact radiotherapy, but these are cur- rently reserved for patients unfit for radical resection, or as a means of palliation.

When radical excision is possible, the aim should be to restore gastrointestinal continuity and continence by preserv- ing the anal sphincter whenever feasible. A sphincter-saving operation (anterior resection) is usually possible for tumours whose lower margin is ≥2 cm above the anorectal junction.

the introduction of the stapled anastomosis and chemoradio- therapy down-staging has enabled many more patients to be treated by a sphincter-saving procedure.

The principles of anterior resection involve radical excision of the cancer along with its complete mesorectal envelope, combined with high proximal ligation of the inferior mesenteric lymphovascular pedicle.

Once the left colon and rectum have been mobil- ised, the distal rectum is divided at least 1 cm (and prefera- bly more) below the distal cancer margin and the specimen removed.

Rectosigmoid cancers and those in the upper third of the rectum are removed by ‘high anterior resection’, in which the rectum and mesorectum are taken to a margin of at least 3 cm distal to the tumour, and a colorectal anastomosis is performed. For tumours in the middle and lower thirds of the rectum, complete removal of the rectum and mesorectum is required, i.e. total mesorectal excision (TME).

Restoration of continuity is usually performed using a stapling technique, which might involve an end-to-end, side-to-end or colopouch construction in low cancers

The retention of at least a part of the rectum in high anterior resection results in better postoperative function, with less risk of anterior resection syndrome,

The bowel is usually prepared by mechanical cleansing using a combination of diet, purgatives and enemas to reduce intra- operative contamination and the risk of surgical site infec- tion.

Early rectal cancers (T1 and good prognosis T2) may be amenable to local transanal excision, preserving much of the rectal reservoir and therefore near normal function.

Histolog- ical analysis of the specimen is then used to assess the ade- quacy of excision with respect to the probability of positive lymph nodes being left behind.

a further radical resec- tion may required if there is a suspicion of incomplete resection or cure of the cancer.

Local excision is usually performed with one of the com- mercially available transanal laparoscopic systems or with equipment modified from taTME procedures

A full-thickness excision of the lesion is performed and the defect closed with sutures or else left open. There is a limit to the height of lesion that can be resected, with more proximal lesions in the upper rectum being difficult.

There has been a move to extend sphincter-saving operations to treat most tumours of the middle and lower thirds of the rectum, thus lowering the abdominoperineal excision rate and the need for permanent colostomy

The term pilonidal sinus describes a condition found in the natal cleft overlying the coccyx, consisting of one or more, usually non-infected, midline openings, which communicate with a fibrous track lined by granulation tissue and containing hair lying loosely within the lumen.

Evidence that supports the theory of the origin of pilonidal sinuses as acquired, can be summarised as follows: ● Interdigital pilonidal sinus is an occupational disease of hairdressers, the hair within the interdigital cleft or clefts being the customers’. Pilonidal sinuses of the axilla and umbilicus have also been reported. ● The age incidence of the appearance of pilonidal sinus (82% occur between the ages of 20 and 29 years) is at variance with the age of onset of congenital lesions. ● Hair follicles have almost never been demonstrated in the walls of the sinus. ● The hairs projecting from the sinus are dead hairs, with their pointed ends directed towards the blind end of the sinus. ● The disease mostly affects men, in particular hairy men. ● Recurrence is common, even though adequate excision of the track is carried out.

The condition is seen much more frequently in men than women, usually after puberty and before the fourth decade of life, and is characteristically seen in dark-haired individuals rather than those with softer blond hair (Oldham). Patients complain of intermittent pain, swelling and discharge at the base of the spine but little in the way of constitutional symp- toms. There is often a history of repeated abscesses that have burst spontaneously or which have been incised, usually away from the midline. The primary sinus may have one or many openings, all of which are strictly in the midline between the level of the sacrococcygeal joint and the tip of the coccyx.

As the natural history of the condition is usually one of regression, in those whose symptoms are relatively minor, simple cleaning out of the tracks and removal of all hair, with regular shaving of the area and strict hygiene, may be recommended

If rest, baths, local antiseptic dressings and the administration of a broad spectrum antibiotic fail to bring about resolution, the abscess should be drained through a small longitudinal incision made over the abscess and off the midline, with thor- ough curettage of granulation tissue and hair. This procedure may or may not be associated with complete resolution.

Karydakis’s operation for pilonidal sinus. A semilateral incision is made around the sinus complex, the diseased component excised and the flap mobilised to allow tension-free closure of the wound off the midline.

The multitude of surgical procedures advocated to eradicate pilonidal disease, combined with the lack of prospective tri- als, attests to the lack of overall superiority of one method over the others.