The Association of Coloproctology of Great Britain and Ireland consensus guidelines in surgery for inflammatory bowel disease.

AIM: There is a requirement of an expansive and up to date review of surgical management of inflammatory bowel disease (IBD) that can dovetail with the medical guidelines produced by the British Society of Gastroenterology. METHODS: Surgeons who are members of the ACPGBI with a recognised interest in IBD were invited to contribute various sections of the guidelines. They were directed to produce a procedure based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. An editorial board was convened to ensure consistency of style, presentation and quality. Each author was asked to provide a set of recommendations which were evidence based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after 2 votes were included in the guidelines. RESULTS: All aspects of surgical care for IBD have been included along with 157 recommendations for management. CONCLUSION: These guidelines provide an up to date and evidence based summary of the current surgical knowledge in the management of IBD and will serve as a useful practical text for clinicians performing this type of surgery.

Chicken or the leg: Sigmoid colon perforation by ingested poultry fibula proximal to an occult malignancy.

INTRODUCTION: Colonic perforation by ingested foreign bodies is exceedingly rare, with the diagnosis made more challenging by patients infrequently recalling any inadvertent ingestion and the poor sensitivity of plain radiography. PRESENTATION OF CASE: The presented case demonstrates that bony perforation of the large bowel might occur immediately proximal to an otherwise occult colonic malignancy. DISCUSSION: Ingestion of foreign bodies is common and rarely results in colonic perforation. However, bony ingestion is not usually remembered and can be missed even with cross-sectional imaging. If present, consideration should be given to the presence of an adjacent concealed colon cancer. CONCLUSION: The co-existence of separate pathology should be carefully assessed in these patients, since this has important implications for relevant investigations and appropriate surgical management.

Volume-outcome analysis of colorectal cancer-related outcomes.

BACKGROUND: Significant associations between caseload and surgical outcomes highlight the conflict between local cancer care and the need for centralization. This study examined the effect of hospital volume on short-term outcomes and survival, adjusting for the effect of surgeon caseload. METHODS: Between 1998 and 2002, 8219 patients with colorectal cancer were identified in a regional population-based audit. Outcomes were assessed using univariable and multivariable analysis to allow case mix adjustment. Surgeons were categorized as low (26 or fewer operations annually), medium (27-40) or high (more than 40) volume. Hospitals were categorized as low (86 or fewer), medium (87-109) or high (more than 109) volume. RESULTS: Some 7411 (90.2 per cent) of 8219 patients underwent surgery with an anastomotic leak rate of 2.9 per cent (162 of 5581), perioperative mortality rate of 8.0 per cent (591 of 7411) and 5-year survival rate of 46.8 per cent. Medium- and high-volume surgeons were associated with significantly better operative mortality (odds ratio (OR) 0.74, P = 0.010 and OR 0.66, P = 0.002 respectively) and survival (hazard ratio (HR) 0.88, P = 0.003 and HR 0.93, P = 0.090 respectively) than low-volume surgeons. Rectal cancer survival was significantly better in high-volume versus low-volume hospitals (HR 0.85, P = 0.036), with no difference between medium- and low-volume hospitals (HR 0.96, P = 0.505). CONCLUSION: This study has confirmed the relevance of minimum volume standards for individual surgeons. Organization of services in high-volume units may improve survival in patients with rectal cancer.

Fecal calprotectin predicts the clinical course of acute severe ulcerative colitis.

OBJECTIVES: Calprotectin is a granulocyte neutrophil-predominant cytosolic protein. Fecal concentrations are elevated in intestinal inflammation and may predict relapse in quiescent inflammatory bowel disease. We aim to investigate fecal calprotectin (FC) as a biomarker in predicting the clinical course of acute severe ulcerative colitis (ASUC). METHODS: In 90 patients with ASUC requiring intensive in-patient medical therapy (January 2005-September 2007), we investigated the discriminant ability of FC to predict colectomy and corticosteroid and infliximab nonresponse. All patients received parenteral corticosteroids as first-line treatment; 21 (23.3%) were also treated with infliximab (5 mg/kg), after failure of corticosteroid therapy. RESULTS: Of 90 patients, 31 (34.4%) required colectomy, including 11 (52.4%) of those treated with infliximab. Overall FC was high (1,020.0 microg/g interquartile range: 601.5-1,617.5). FC was significantly higher in patients requiring colectomy (1,200.0 vs. 887.0; P=0.04), with a trend toward significance when comparing corticosteroid nonresponders and responders (1,100.0 vs. 863.5; P=0.08), as well as between infliximab nonresponders and responders (1,795.0 vs. 920.5; P=0.06). Receiver-operator characteristic curve analysis yielded an area under the curve of 0.65 to predict colectomy (P=0.04), with a maximum likelihood ratio of 9.23, specificity 97.4%, and sensitivity 24.0% at a cutoff point of 1,922.5 microg/g. Kaplan-Meier analyses showed that using 1,922.5 microg/g over a median follow-up of 1.10 years, 87% of patients will need subsequent colectomy. CONCLUSIONS: This is the first data set to demonstrate that FC levels are dramatically elevated in severe UC. These data raise the possibility that this biomarker can predict response to first or second-line medical therapy in this setting.

Involvement of surgical trainees in surgery for colorectal cancer and their effect on outcome.

OBJECTIVE: Surgical training in the UK is undergoing substantial changes. This study assessed: 1) the training opportunities available to trainees in operations for colorectal cancer, 2) the effect of colorectal specialization on training, and 3) the effect of consultant supervision on anastomotic complications, postoperative stay, operative mortality and 5-year survival. METHOD: Unadjusted and adjusted comparisons of outcomes were made for unsupervised trainees, supervised trainees and consultants as the primary surgeon in 7411 operated patients included in the Northern Region Colorectal Cancer Audit between 1998 and 2002. RESULTS: Surgery was performed in 656 (8.8%) patients by unsupervised trainees and in 1578 (21.3%) patients by supervised trainees. Unsupervised operations reduced from 182 (12.4%) in 1998 to 82 (6.1%) in 2002 (P < 0.001). Consultants with a colorectal specialist interest were more likely than nonspecialists to be present at surgical resections (OR 1.35, 1.12-1.63, P = 0.001) and to provide supervised training (OR 1.34, 1.17-1.53, P < 0.001). Patients operated on by unsupervised trainees were more often high-risk patients, however, consultant presence was not significantly associated with operative mortality (OR 0.83, 0.63-1.09, P = 0.186) or survival (HR 1.02, 0.92-1.13, P = 0.735) in risk-adjusted analysis. Supervised trainees had a case-mix similar to consultants, with shorter length of hospital stay (11.4 vs 12.4 days, P < 0.001), but similar mortality (OR 0.90, 0.71-1.16, 0.418) and survival (HR 0.96, 0.89-1.05, P = 0.378). CONCLUSION: One third of patients were operated on by trainees, who were more likely to perform supervised resections in colorectal teams. There was no difference in anastomotic leaks rates, operative mortality or survival between unsupervised trainees, supervised trainees and consultants when case-mix adjustment was applied. This study would suggest that there is considerable underused training capacity available.

Outcomes of the rectal remnant following colectomy for ulcerative colitis.

OBJECTIVE: Controversy surrounds the optimal surgical management of the distal rectal remnant during colectomy for ulcerative colitis (UC) and the potential benefit from the placement of a rectal catheter for remnant drainage. This study reviews the clinical outcomes of patients who have undergone colectomy for UC with intra-peritoneal closure of the rectal remnant. METHOD: Analysis of prospective data lodged on Lothian Surgical Audit databases from patients treated in a tertiary coloproctology unit over 11 years. RESULTS: One hundred and fifty-nine patients were identified, the mean age was 41.9 years, 63% were men. Failure of maximal medical therapy necessitated surgery for 78.1% patients, while 12.6% had acute perforation and 11.9% had toxic megacolon. Complications included five (3.1%) stump dehiscences, eight (5.0%) intra-abdominal/pelvic collections, four (2.5%) significant wound infections, three (1.9%) small bowel obstructions and three (1.9%) deaths. Within the follow-up period, 62.3% patients had an ileo-pouch anal anastomosis (IPAA), 7.5% patients had a completion proctectomy, 10.1% patients within the series had a retained rectal remnant after 1 year follow up, the remaining patients had less than 1 year follow up. CONCLUSION: The intra-peritoneal rectal stump following colectomy for UC is associated with low rates of pelvic sepsis and a high proportion of patients successfully proceeding to IPAA.

Bacterial contamination of hospital bed-control handsets in a surgical setting: a potential marker of contamination of the healthcare environment.

INTRODUCTION: Patients undergoing colorectal surgical resections have a high incidence of surgical site infection (SSI). Many patient-specific risk factors have been recognised in association with SSI in such patients, but environmental contamination is increasingly recognised as a contributor to hospital-acquired infection (HAI). This study set out to describe the bacterial contamination of the patient environment, using hospital bed-control handsets, as they are frequently handled by both staff and patients and represent a marker of environmental contamination. PATIENTS AND METHODS: On two unannounced sampling events, 1 week apart, 140 bacteriological assessments were made of 70 hospital bed control handsets within a specialist colorectal surgical unit. RESULTS: Of the handsets examined, 67 (95.7%) demonstrated at least one bacterial species (52.9% grew 1, 30% grew 2 and 12.9% grew 3 or more bacterial species). Of these, 29 (41.4%) bed-control handsets grew bacteria known to cause nosocomial infection, including 22 (31.4%) handsets which grew Enterococcus spp., 9 (12.9%) which grew MRSA, 2 (2.9%) which grew MSSA, 2 (2.9%) which grew coliforms, and 1 (1.4%) handset which grew anaerobes. At 1-week follow-up, 31 bed-control handsets showed evidence of contamination by the same bacterial species. CONCLUSIONS: This study revealed high levels of bacteria known to cause HAI, contaminating hospital bed-control handsets in a surgical setting. Further study is now required to confirm whether hospital environmental contamination is causally involved in SSI.

Impact of surgeon volume and specialization on short-term outcomes in colorectal cancer surgery.

BACKGROUND: Several studies have shown a relationship between surgeon volume and outcomes in colorectal cancer surgery. The aim of this study was to determine the impact of surgeon volume and specialization on primary tumour resection rate, restoration of bowel continuity following rectal cancer resection, anastomotic leakage and perioperative mortality. METHODS: The Northern Region Colorectal Cancer Audit Group conducts a population-based audit of patients with colorectal cancer managed by surgeons. This study examined 8219 patients treated between 1998 and 2002. Outcomes were modelled using multivariate logistic regression analysis. RESULTS: Tumour resection was performed in 6949 (93.8 per cent) of 7411 patients. High-volume surgeons with an annual caseload of at least 18.5 (odds ratio (OR) 1.53 (95 per cent confidence interval (c.i.) 1.10 to 2.12); P = 0.012) and colorectal specialists (OR 1.42 (95 per cent c.i. 1.06 to 1.90); P = 0.018) were more likely to perform elective sphincter-saving rectal surgery. In elective surgery, the risk of perioperative death was lower for high-volume surgeons (OR 0.58 (95 per cent c.i. 0.44 to 0.76); P < 0.001), but this was not the case in emergency surgery. CONCLUSION: High-volume surgeons had lower perioperative mortality rates for elective surgery, and were more likely to use restorative rectal procedures.

Variance of surgeons versus pathologists in staging of colorectal cancer.

AIM: Accurate staging of colorectal cancer depends on adequate retrieval and reporting of lymph nodes in the specimen. The presence of positive lymph nodes is an indication for adjuvant therapy. Both surgeons and pathologists influence the number of lymph nodes that are retrieved and reported in specimens. Although several recommendations exist in the literature regarding the minimum number of lymph nodes required for reliable staging, the relationship of examined to infiltrated lymph nodes has not been clarified. The aims of this study were to examine variance among surgeons and pathologists in the retrieval and reporting of lymph nodes in colorectal cancer specimens; to examine the relationship between retrieved/examined lymph nodes and infiltrated lymph nodes; to identify in our own series the minimum number of retrieved lymph nodes required to secure accurate staging. METHODS: Cross-sectional study of 284 patients with colorectal cancer followed in our hospital and retrospective analysis of histopathology reports. Correlation analysis, ANOVA, and survival analysis were performed on the data. RESULTS: There were 127 patients with cancer of the rectum and 157 patients with cancer of the colon under follow-up. The median number of lymph nodes per specimen was 8 (range 0-29). There was no difference in the number of retrieved lymph nodes among 9 surgeons. There were 2 outliers among pathologists, with one reporting a mean of 11.4 (9.8-12.9) 95% CI nodes per specimen and another reporting a mean 4.9 (3.6-6.2) 95% CI nodes per specimen. Dukes and T stage did not affect the number of nodes. Correlation analysis revealed a linear correlation between the total number of reported lymph nodes and the existence of positive lymph nodes. From the correlation equation we calculated that, in order to have one positive node, a minimum of 8.4 nodes was required in the specimen. Therefore, in our group of patients, a minimum of 8.4 nodes was required for accurate Dukes staging. However, survival analysis did not show any difference between patients with more and patients with less than 9 reported lymph nodes. CONCLUSIONS: Variance among pathologists exists and may be at least as important as variance among surgeons. Specialisation of pathologists similar to that of surgeons as well as employment of new techniques may be required . There is a linear correlation between the number of examined lymph nodes and the presence of positive nodes in a colorectal cancer specimen. This linear correlation makes the calculation of the minimum number of lymph nodes possible. In our series a minimum of nine nodes must be examined. However, we have not demonstrated an effect of inadequate nodes numbers on survival, possibly because survival in colorectal cancer is multifactorial.

Retrospective review of laser therapy for palliation of colorectal tumours.

Patients with inoperable colorectal tumours will often require symptomatic relief due to the nature of extensive disease spread or existing co-morbidities. The use of laser treatment for palliation of tumours in the lower gastrointestinal tract has become an attractive treatment option for such patients. This paper presents the results of a retrospective review of 58 case notes in order to determine the effectiveness of laser therapy in palliating symptoms of colorectal tumours. In addition, the paper aims to identify which colorectal symptoms laser is best used to palliate. The study was conducted in a regional coloproctology unit at the Western General Hospital in Edinburgh. The main findings show that 52% (n=30) of patients had successful (complete/good) resolution of symptoms, 36% (n=21) had a poor response and 12% (n=7) had no resolution of symptoms from laser therapy. Of all documented symptoms, this study found that laser is most effective at palliating obstructive symptoms. It also has beneficial application in the palliation of bleeding and mucous discharge. It is less effective for the anal symptoms of tenesmus and pain and for stool related symptoms such as diarrhoea, constipation, frequency and incontinence.

Paediatric resuscitation by phone: the call back.

OBJECTIVE: To assess whether the nationwide introduction of standardized paediatric resuscitation training has resulted in an increase in resuscitation knowledge from 1995 and whether this increase in knowledge is greater in those who have attended a resuscitation training course within the last year. METHODS: National telephone survey of paediatric residents. RESULTS: A total of 128 out of a possible 140 residents responded. The mean score in 2002 was significantly higher than in 1995. Those 2002 respondents who had attended a course scored significantly higher than both 1995 respondents, and those 2002 respondents who had not attended a course. There was no significant difference between those 2002 respondents who had not attended a course and the 1995 respondents. CONCLUSION: There has been a significant increase in resuscitation knowledge from 1995 to 2002. This improvement has occurred over a period coinciding with the nationwide introduction of standardized resuscitation training. The authors suggest that this improvement is, in part, due to the introduction of standardized paediatric resuscitation training.

Assessment of outcomes after colorectal cancer resection in the elderly as a rationale for screening and early detection.

BACKGROUND: Clinical, social and survival outcomes in elderly patients undergoing bowel cancer surgery were studied to explore the justification for the current upper age limit in colorectal cancer screening programmes. METHODS: Scottish national data were analysed to determine age-specific population survival following a diagnosis of colorectal cancer. Detailed analysis of outcome variables was undertaken in a cohort of 180 patients aged over 80 years who underwent resection of colorectal cancer. RESULTS: Population analysis revealed that the absolute risk of developing colorectal cancer was highest in those aged over 80 years, but relative survival was disproportionately poor. Of 180 patients in this age group, 30.0 per cent required an emergency procedure and only 4.6 per cent had Dukes' stage A tumours. Determinants of all-cause mortality were tumour stage (P < 0.001) and degree of co-morbidity (P = 0.004). Some 88.0 per cent of elderly patients returned to the same category of accommodation as that before admission. CONCLUSION: Colorectal cancer is increasingly common in people aged over 80 years and survival is disproportionately poor compared with that in other age groups. Elective management of early-stage cancer has a better outcome than emergency surgery. The majority of patients maintain social independence. These population and hospital data provide a rationale for early, and even presymptomatic, detection of colorectal cancer in the elderly.

Chronic pain after laparoscopic and open mesh repair of groin hernia.

BACKGROUND: The aim of this study was to compare the incidence of chronic pain or discomfort after laparoscopic totally extraperitoneal (TEP) repair and open mesh repair of groin hernia, and to assess the impact of such pain on patients' physical activity. METHODS: A postal questionnaire was sent to patients who had TEP or open mesh repair of groin hernia between January 1998 and December 1999. The patients were asked about any persistent pain or discomfort in relation to the groin hernia repair and whether this pain or discomfort restricted their ability to undertake physical or sporting activity. RESULTS: Of the 560 available patients 454 (81.1 per cent) replied. Laparoscopic TEP repair was performed in 240 patients (52.9 per cent) and open mesh repair in 214 (47.1 per cent). Of the 454 patients, 136 (30.0 per cent) reported chronic groin pain or discomfort, which was significantly more common after open repair than after laparoscopic repair (38.3 versus 22.5 per cent; P < 0.01). Chronic groin pain or discomfort restricted daily physical or sporting activity in 18.1 per cent of the patients. The patients who had open repair complained of significantly more restriction of daily physical activity than patients who underwent laparoscopic repair (walking, P < 0.05; lifting a bag of groceries, P < 0.01). CONCLUSION: Chronic pain or discomfort was reported by 30.0 per cent of patients after groin hernia repair and was significantly more common after open mesh repair than after laparoscopic TEP repair. It restricted physical or sporting activities in 18.1 per cent of the patients and significantly more so after open mesh repair.

Unconventional carrier-mediated ferromagnetism above room temperature in ion-implanted (Ga, Mn)P:C.

Ion implantation of Mn ions into hole-doped GaP has been used to induce ferromagnetic behavior above room temperature for optimized Mn concentrations near 3 at. %. The magnetism is suppressed when the Mn dose is increased or decreased away from the 3 at. % value, or when n-type GaP substrates are used. At low temperatures the saturated moment is on the order of 1 Bohr magneton, and the spin wave stiffness inferred from the Bloch-law T(3/2) dependence of the magnetization provides an estimate T(c)=385 K of the Curie temperature that exceeds the experimental value, T(c)=270 K. The presence of ferromagnetic clusters and hysteresis to temperatures of at least 330 K is attributed to disorder and proximity to a metal-insulating transition.

The contemporary management of haemorrhoids.

BACKGROUND: New concepts in the management of haemorrhoidal disease have recently rekindled interest in this common pathology. General and subspecialist colorectal surgeons were surveyed to assess their impact on the current management of haemorrhoids. METHODS: A questionnaire was sent to all members of the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and the Association of Surgeons of Great Britain and Ireland (ASGBI). Regarding indications for surgery, surgical techniques, day case haemorrhoidectomy (DCH) and postoperative treatment regimens. ASGBI members were asked to state their subspecialist interest and estimated time devoted to colorectal practice. RESULTS: There were 406 (71%) ACPGBI respondents and 483 (68%) ASGBI respondents. Eighty-four (12%) ASGBI respondents performed no elective colorectal surgery. One hundred and ninety-nine (35%) of ACPGBI respondents saw between 6 and 10 new haemorrhoid patients per week whereas three hundred (42%) of ASGBI respondents saw between 1 and 5 per week. Non-operative management included routine advice on fluid and diet by the majority of surgeons, with banding carried out in 79% (ACPGBI) and 75% (ASGBI) and injection sclerotherapy in 61% (ACPGBI) and 56% (ASGBI). The Milligan Morgan haemorrhoidectomy was performed in 265 (46%; ACPGBI) and 336 (47%; ASGBI). ACPGBI members used Submucosal diathermy (148, 26%vs 67, 9%; ASGBI (P < 0.01; chi2 test with Yates correction)) and stapled anoplasty (61, 11%vs 14, 2%; ASGBI (P < 0.01; chi2 test with Yates correction)) more often. DCH was performed in 117 (20%; ACPGBI) and in 48 (7%; ASGBI)(P < 0.01; chi2 test with Yates correction). CONCLUSIONS: In this sample of surgeons, operative management varies according to specialist interest. There was a trend towards day case haemorrhoidectomy. Whilst more surgeons have accepted the use of postoperative techniques to reduce pain, only a small minority have, as yet, adopted new surgical techniques such as stapling.

Aggressive local treatment for screen-detected DCIS results in very low rates of recurrence.

AIMS: To review our institution's practice of treatment of a mammographically detected population of ductal carcinoma in situ (DCIS) patients and to determine the outcome. METHODS: Between April 1989 and March 1994, 304 women with median age 59 years (range 51-65) with DCIS detected on screening mammogram, were treated in the Newcastle General and Royal Victoria Infirmary Hospitals, Newcastle-upon-Tyne, UK. More than half of the women (n=176, 57.8%) decided to have mastectomy. Other treatment options were wide local excision (WLE) with radiotherapy (n=97, 32%) and WLE alone (n=31, 10.2%). All except five received adjuvant hormone treatment. RESULTS: Predominant DCIS was comedo in 122 (42%), followed by cribriform in 87 (30%) and micropapillary in 44 (15%) cases. Grade I was found to be commonest grade (54%) followed by grade II (27%) and grade III (11%). With a median follow-up of 88 months, there were six (2%) recurrences, all of which were in women who were given breast conservation treatment, WLE with radiotherapy (n=1, 1%) and without radiotherapy (n=5, 16.6%). Mastectomy in this series was not associated with any recurrence at all. In three cases the recurrence was invasive, one of who also had distant metastasis. CONCLUSIONS: The findings of this study suggest that in women with DCIS suitable for breast conservation, WLE when combined with radiotherapy is associated with a very low recurrence rate.

High expression of the trefoil protein TFF1 in interval breast cancers.

Breast cancer screening is important for the early detection of breast cancer. Tumors that become symptomatic in the screening interval are known as interval cancers but the reasons for their rapid progression are unknown. Estrogen receptor expression is lower in interval cancers suggesting that they may have reduced hormonal responsiveness. To investigate this hypothesis we have measured the expression of the estrogen receptor and three estrogen-responsive genes (cathepsin D, progesterone receptor, and TFF1) in screen-detected and interval breast cancers. The expression of the protease cathepsin D was not associated with estrogen receptor in either group of tumor. Progesterone receptor expression was highly correlated with that of the estrogen receptor in both groups of tumors but it was not expressed at significantly different levels in the two groups of tumors. Expression of TFF1, a cellular motogen, was correlated with estrogen receptor in screen-detected but not interval cancers and was expressed at markedly higher levels in interval breast tumors, the group that expresses lower levels of estrogen receptor. Interval cancers are characterized by high levels of expression of TFF1 and/or Ki67 suggesting that cell migration and cell division play important roles in the rapid progression of interval cancers. The observation that TFF1 expression in interval cancers tends to be estrogen-independent and that interval cancers have reduced estrogen receptor expression suggests they may have a reduced response to hormone therapy.

Hydrostatic pressure induced changes in the cytoarchitecture of pheochromocytoma (PC-12) cells.

Confocal microscopy, in association with three-dimensional reconstruction, revealed that microtubules and microfilaments in differentiating PC-12 cells were disrupted in a dose-dependent manner following pressure treatment. Hydrostatic pressure caused cell rounding, microtubule and microfilament disorganization, neurite retraction and the formation of a microtubule ring adjacent to the cell surface. Volume analysis from computer-generated reconstructed cells, at atmospheric pressure, showed that the apparent volume of microtubules and microfilaments, normalized to 100 units, was 22 and 11 respectively. At 4000 and 8000 psi, the apparent microtubule volume was reduced to 16 and 12 units, respectively, and the apparent microfilament volume was reduced to 8 and 5 units, respectively. Thus, the apparent microtubule and microfilament volumes in PC-12 cells decreased as pressure increased. In the presence of taxol and phalloidin which stabilize the cytoarchitecture, cells resist the effects of hydrostatic pressure. In the presence of colchicine and cytochalasin D compounds which destabilize the cytoarchitecture, cells are more susceptible to the disrupting effects of hydrostatic pressure. The effects of hydrostatic pressure on cell morphology were reversible.