Randomized clinical trial of local bupivacaine perfusion versus parenteral morphine infusion for pain relief after laparotomy

BACKGROUND

Opioids are often used to decrease pain following laparotomy but are associated with unwanted side-effects. The effectiveness of local perfusion of bupivacaine 0.5 per cent following laparotomy was studied.

METHODS

A prospective randomized study involving patients undergoing laparotomy for major colorectal surgery using a left iliac fossa skin crease incision was undertaken. Patients were randomized to receive either intermittent intravenous morphine infusion on demand with patient-controlled analgesia (PCA group) or continuous wound perfusion of local bupivacaine 0.5 per cent for 60 h (LA group).

RESULTS

Seventy patients were recruited, 35 in each group. Patient demographics, surgical and recovery variables and complications were comparable in the two groups. The wound lengths were similar (median 14 cm in both groups). There was no statistically significant difference in postoperative pain scores at rest and with movement between the two groups, except for pain scores at rest on the first postoperative day (P = 0.03). The median total amount of morphine used was significantly greater in the PCA group (median 38 versus 0 mg in the LA group; P < 0.001).

CONCLUSION

Direct continuous local wound perfusion of bupivacaine 0.5 per cent is as effective as PCA for postoperative pain relief after laparotomy. It is a safe and feasible alternative to parenteral opioids.

Efficiency of database search for identification of mutated and modified proteins via mass spectrometry

Although protein identification by matching tandem mass spectra (MS/MS) against protein databases is a widespread tool in mass spectrometry, the question about reliability of such searches remains open. Absence of rigorous significance scores in MS/MS database search makes it difficult to discard random database hits and may lead to erroneous protein identification, particularly in the case of mutated or post-translationally modified peptides. This problem is especially important for high-throughput MS/MS projects when the possibility of expert analysis is limited. Thus, algorithms that sort out reliable database hits from unreliable ones and identify mutated and modified peptides are sought. Most MS/MS database search algorithms rely on variations of the Shared Peaks Count approach that scores pairs of spectra by the peaks (masses) they have in common. Although this approach proved to be useful, it has a high error rate in identification of mutated and modified peptides. We describe new MS/MS database search tools, MS-CONVOLUTION and MS-ALIGNMENT, which implement the spectral convolution and spectral alignment approaches to peptide identification. We further analyze these approaches to identification of modified peptides and demonstrate their advantages over the Shared Peaks Count. We also use the spectral alignment approach as a filter in a new database search algorithm that reliably identifies peptides differing by up to two mutations/modifications from a peptide in a database.

Stapled hemorrhoidectomy--cost and effectiveness. Randomized, controlled trial including incontinence scoring, anorectal manometry, and endoanal ultrasound assessments at up to three months

PURPOSE

Stapled hemorrhoidectomy is performed without leaving painful perianal wounds. The aim of this study was to assess any benefits, compared with a conventional open diathermy technique.

METHODS

A total of 119 consecutive patients with prolapsed irreducible hemorrhoids were randomly assigned (conventional open diathermy technique = 62; stapled hemorrhoidectomy = 57). Preoperative fecal incontinence scoring, anorectal manometry, and endoanal ultrasound were performed. Postoperatively, these were repeated at up to three months with pain scores, analgesic requirements, quality of life assessment, and total related medical costs.

RESULTS

Conventional open diathermy technique was quicker to perform (mean, 11.4 (standard error of the mean, 0.9) vs. 17.6 (3.1) minutes). Hospitalization was similar, but conventional open diathermy technique patients felt more pain during defecation (5.1 (0.4) vs. 2.6 (0.4); P < 0.005) at two weeks, and analgesic requirements were more for up to six weeks (P < 0.05). Up to the latter, 85.5 percent conventional open diathermy technique wounds remained unhealed, with more bleeding (33 (53.2 percent) vs. 19 (33.3 percent); P < 0.05) and pruritus (27 (43.5 percent) vs. 9 (15.8 percent); P < 0.05). Total complication rates were similar (conventional open diathermy technique 16 (25.8 percent) vs. stapled hemorrhoidectomy 10 (17.5 percent)), including mild strictures and bleeding in both groups. Minor incontinence occurred postoperatively in two conventional open diathermy technique and two stapled hemorrhoidectomy patients at six weeks. Endoanal ultrasound internal anal sphincter defects were found in the incontinent conventional open diathermy technique patients, but were asymptomatic in another one conventional open diathermy technique and one stapled hemorrhoidectomy. Only one patient (conventional open diathermy technique with internal sphincter defect) remained incontinent at three months. Changes between preoperative and postoperative anorectal manometry were similar in the two groups. Patients' satisfaction scores and quality of life assessments were also similar. Conventional open diathermy technique patients resumed work later (mean 22.9 (1.8) vs. 17.1 (1.9) days; P < 0.05), but the total costs incurred were less ($921.17 (16.85) vs. $1,283.09 (31.59); P < 0.005).

CONCLUSIONS

Stapled hemorrhoidectomy is a safe and effective option in treating irreducible prolapsed piles. It is more expensive but less painful, with less time needed off work. Nonetheless, long-term results are still awaited.

Postoperative intra-abdominal free gas after open colorectal resection

PURPOSE

An erect chest radiograph for subdiaphragmatic free gas can be a useful adjunct in detecting a defect in gastrointestinal continuity. The usefulness of this test after laparotomy has not been defined, because the period of persistence of free gas is unknown. We set out to determine the length of time for natural absorption of postlaparotomy pneumoperitoneum in a prospective cohort study.

METHOD

Plain erect chest radiographs were performed on the second and fourth postoperative day and daily thereafter until the disappearance of subdiaphragmatic free gas after laparotomy.

RESULTS

Seventy-five consecutive patients were studied after informed consent. The mean age was 62.1 (standard error of the mean, 1.7) years. On the fifth postoperative day, sixth postoperative day, and seventh postoperative day, 71.6, 80, and 89 percent of patients, respectively, had no visible subdiaphragmatic gas. Five patients had gas persisting beyond the tenth postoperative day. Two of these patients did not have an anastomosis. The use of drainage tubes did not affect significantly the mean time to disappearance of subdiaphragmatic free gas (4.5 vs. 4.9 days; P = 0.45: t-test). The duration of surgery, body mass index, and time to resume bowel function had no significant effect on gas disappearance. Two patients had a clinical leak on the fifth postoperative day. This was manifested as an increase in the collection of subdiaphragmatic gas during the course of a day.

CONCLUSION

By the sixth postoperative day 80 percent of patients had no subdiaphragmatic free gas on an erect chest radiograph regardless of the presence of a drainage tube. The erect chest radiograph may therefore be a simple and readily available adjunct in the evaluation of postoperative abdominal pain, especially after the sixth postoperative day when a similar prior examination is done routinely on the fourth postoperative day for comparison.

Donor site morbidity following vascularized fibular grafting

We examined donor site morbidity in thirty-nine patients with avascular necrosis of the femoral head treated by curettage and transplantation of a free ipsilateral fibular graft. Utilising our donor site morbidity questionnaire, scar, functional loss, wound healing, complications, and pain were analysed. Subjective complaints and objective findings were evaluated and compared. Subjective complaints were common and included a sense of instability in 42% and a sense of weakness in 37%. However, objective findings were limited. No clinical instability could be elicited and only great toe flexion (29%) and extension (43%) were found to be mildly weak. Only one patient required reoperation for a donor site problem (2%). Eighty-nine percent were pain free at time of follow-up, and 93% felt the scar was good. Range of motion of the knee and ankle of the donor site leg was not different from the nonoperated leg. Donor site morbidity for avascular necrosis of the femoral head is low.

New chiral catalysts for reduction of ketones

The condensation of o-(diphenylphosphino)benzaldehyde and various chiral diamine gives a series of diimino-diphosphine tetradentate ligands, which are reduced with excess NaBH4 in refluxing ethanol to afford the corresponding diaminodiphosphine ligands in good yield. The reactivity of these ligands toward trans-RuCl2(DMSO)4 and [Rh(COD)Cl]2 had been investigated and a number of chiral Ru(II) and Rh(I) complexes with the PNNP-type ligands were synthesized and characterized by microanalysis and IR, NMR spectroscopic methods. The chiral Ru(II) and Rh(I) complexes have proved to be excellent catalyst precursors for the asymmetric transfer hydrogenation of aromatic ketones, leading to optically active alcohols in up to 97% ee.

Anal sphincter injuries from stapling instruments introduced transanally: randomized, controlled study with endoanal ultrasound and anorectal manometry

PURPOSE

Injury sustained from the transanally introduced stapling technique was assessed by comparison with biofragmentable anastomotic ring anastomosis, which excluded anal manipulation.

METHODS

A randomized, controlled trial was conducted on consecutive patients undergoing sigmoid colectomy (where pelvic nerve injury was avoided). A bowel function questionnaire was administered six months after surgery. Anorectal manometry and endoanal ultrasonography were performed preoperatively and at six months postoperatively. The observers were blinded to the randomization.

RESULTS

There were 18 patients in the transanally introduced stapling technique group and 17 patients in the biofragmentable anastomotic ring group, with no differences in age, gender, Dukes staging, and follow-up. Three of the transanally introduced stapling technique patients had occasional liquid soiling, which was absent in biofragmentable anastomotic ring patients. Mean change in resting anal pressures was also significantly impaired when compared with patients with biofragmentable anastomotic ring (P = 0.007). Endosonographic internal sphincter fragmentation was found in five transanally introduced stapling technique patients but none after biofragmentable anastomotic ring anastomosis (P = 0.046). Internal sphincter fragmentation was associated with the impaired resting pressures (P = 0.007). External sphincter deficiencies were found after transanally introduced stapling technique in two patients (biofragmentable anastomotic ring = 0), and these were associated with the soiling (P = 0.005).

CONCLUSIONS

The transanally introduced stapling technique may result in anal sphincter defects and impaired anal pressures when assessed at six months of follow-up.

Transanal repair of rectocele corrects obstructed defecation if it is not associated with anismus

PURPOSE

Rectocele is often associated with anorectal symptoms. Various surgical techniques have been described to repair the rectocele. The surgical results are variable. This study evaluated the results of transanal repair of rectocele, with particular emphasis on the impact of concomitant anismus on postoperative functional outcome.

METHODS

Fifty-nine consecutive females who underwent transanal repair of rectocele for obstructed defecation were prospectively reviewed. All 59 patients were parous with a median parity of 2 (range, 1-6) and a median age of 58 (range, 46-68) years. The median length of follow-up was 19 (range, 6-40) months. Anismus was detected by anorectal physiology and defecography. The functional outcome was assessed by a standard questionnaire, physical examination, anorectal manometry, neurophysiology, and defecography. The quality-of-life index was obtained using a visual analog scale (from 1-10, with 10 being the best).

RESULTS

The functional outcome of transanal repair of rectocele was superior in patients without anismus. Forty (93 percent) of the 43 patients without anismus showed improved evacuation after repair compared with 6 (38 percent) of the 16 patients with anismus (P<0.05). The quality-of-life index improved (9 vs. 4) if anismus was not present (P<0.05). There were minimal complications. Hemorrhage requiring blood transfusion (2 units) occurred in one patient and urinary retention in another.

CONCLUSION

Transanal repair of rectocele is safe and, in the absence of anismus, effectively corrects obstructed defecation.

Breast cancer found at the time of breast reduction

In a recent study involving 27,500 women who had breast reduction surgery in Ontario, Canada, 17 women who were diagnosed as having breast cancer at the time of their breast reduction surgery were identified. The aims of this study were to (1) describe a population-based series of patients who had breast cancer diagnosed at the time of breast reduction, (2) describe the treatment of these cancers, and (3) compare their survival rate with survival in patients in the general population who had breast cancer. Information about these women, their treatment, and outcome was extracted from hospital records, pathology reports, and reports from regional cancer centers. The chance of finding an invasive breast cancer at the time of breast reduction was 0.06 percent, which is lower than what has been reported previously. Sixty-seven percent of these women were treated with total mastectomy. In the remaining 33 percent, who were treated with partial mastectomy, the entire tumor was removed at the time of breast reduction. Fifty percent of the women were treated with radiation, and 25 percent were treated with chemotherapy or hormonal therapy. Compared with women in the general population of Ontario who have breast cancer, women whose breast cancer is discovered during breast reduction surgery are more likely to be treated with complete mastectomy and less likely to be treated with radiotherapy or chemotherapy. Seventy-one percent of the breast reduction group were axillary node-negative at diagnosis, compared with 58 percent in the general population of women with breast cancer. Survival from breast cancer in women diagnosed at the time of breast reduction (88 percent, 5-year survival) was better than survival from breast cancer in the general population (77 percent). These findings suggest that cancers found in women at the time of breast reduction are less advanced, possibly because they are diagnosed at an earlier stage.

A follow-up study of 105 women with breast cancer following reduction mammaplasty

Reduction mammaplasty is one of the most common procedures performed by plastic surgeons in Canada. In a recent study of 27,500 women in the province of Ontario who underwent breast reduction surgery, 105 women were identified who developed breast cancer after reduction mammaplasty. The purpose of this study was to compare women who had breast cancer and had a previous breast reduction with women who had breast cancer but did not have a breast reduction. Specifically, we wanted to document patient demographics, cancer type, surgical and nonsurgical treatment, and eventual outcome. A comparison group of non-breast reduction women was taken from the cohort of breast cancer patients in the province of Ontario, and the two groups were matched for age, year of diagnosis, and place of diagnosis. It was found that (1) the average age at diagnosis of breast cancer is significantly younger for women who have had previous breast reduction surgery than for those who have not; (2) the median interval between breast reduction and cancer is 5 years; (3) the type, location, and side of breast cancers are similar in the two groups of women; (4) breast reduction does not significantly increase or decrease survival rate from breast cancer; and (5) women who have had breast reduction receive the same treatment for their breast cancer as women who have not had reduction mammaplasty.

Cecal intubation model in the rat that facilitates selective in vivo study of colonic epithelial biology: preliminary report

PURPOSE

A free-living animal model with ready and repetitive access to selected regions of the large bowel and with minimally altered bowel anatomy and physiology would facilitate the in vivo study of luminal factors on the colonic mucosa in a steady-state environment. This study describes a novel model of large-bowel intubation in the rat.

METHOD

Four Sprague-Dawley rats (240-260 g) had laparotomy and intubation of the distal colon and the cecum via a cecotomy with the use of two small tubes with restraints and transmural anchors. The tubes were tunneled and anchored to the back for infusion of fluid directly into the colon. Tube positions were studied when the animals were killed. Animals were fed on either a 10 percent fiber diet or a fiber-free diet. Stathmokinetic assessment of the distal colon was performed after one week of infusion with phosphate-buffered saline and sodium n-butyrate.

RESULTS

The technique produced an easy access without affecting the weight gain of the animals after recovery. Tube positions were accurate after three weeks at the time the animals were killed. Infusions of phosphate-buffered saline and n-butyrate were well tolerated. n-Butyrate infusions twice daily for a week reversed the atrophy in the colonic mucosa induced by dietary fiber deprivation.

CONCLUSION

An in vivo large-bowel intubation model permitting selective delivery of luminal factors provides an effective option for the study of colonic mucosal biology.

Diminutive cancers of the colon and rectum: comparison between flat and polypoid cancers

A comparative study of polypoid and flat colorectal cancers less than 20 mm in size was made. A review of the characteristics of 56 polypoid cancers and 29 flat cancers treated between April 1989 and January 1996 was performed. Both groups of cancers showed similar age and location distribution. Polypoid cancers were more likely to be well differentiated (38%) than were flat cancers (17%) (P < 0.05). Flat cancers were more likely to have reached the serosa (52% vs 12%; P < 0.01) and also demonstrated a higher frequency of lymph node involvement (41% vs p 9%) (P < 0.01) when compared to polypoid cancers. Flat colorectal cancers belong to a distinct subset which demonstrates greater biological aggressiveness than polypoid cancers of equivalent size.

The Colorectal Cancer Recurrence Support (CARES) System

Colorectal cancer has risen in incidence to become the second commonest form of cancer in Singapore. The primary treatment is surgery but up to 50% of patients still suffer from recurrence of the cancer after surgery. Early identification of recurrence will increase the effectiveness of therapy and the survival of patients. This paper describes the CARES (Cancer Recurrence Support) System, whose objective is to predict the recurrence of colorectal cancer, using Case-based Reasoning (CBR), and supported by other techniques such as data mining and natural language processing. The CARES System employs CBR to compare and contrast between the new and past colorectal cancer patient cases, and makes inferences based on those comparisons to determine the high risk patient groups. The features and functionality of the system are described.

Broadly tunable mid-infrared femtosecond optical parametric oscillator using all-solid-state-pumped periodically poled lithium niobate

We describe a high-repetition-rate femtosecond optical parametric oscillator (OPO) that was broadly tunable in the mid infrared. The all-solid-state-pumped OPO was based on quasi-phase matching in periodically poled lithium niobate. The idler was tunable from approximately 1.7 mum to beyond 5.4 mum, with maximum average power levels greater than 200 mW and more than 20 mW of average power at 5.4 mum. We used interferometric autocorrelation to characterize the mid-infrared idler pulses, which typically had durations of 125 fs. This OPO had a pumping threshold as low as 65 mW of average pump power, a maximum conversion efficiency of >35% into the near-infrared signal, a slope efficiency for the signal of approximately 60%, and a maximum pump depletion of more than 85%.

Prospective randomized trial of drainage alone vs. drainage and fistulotomy for acute perianal abscesses with proven internal opening

PURPOSE

Incision and drainage (I & D) with concurrent or delayed fistulotomy is the usual treatment for abscess-fistula with a demonstrated internal opening. We compared incision and drainage alone vs. with concurrent fistulotomy for perianal abscesses with a demonstrated internal opening.

METHODS

Consecutive patients with acute perianal abscesses and a demonstrated internal opening were prospectively randomized into either the I & D group or drainage with concurrent fistulotomy group. They were followed up at one month, three months, and one year.

RESULTS

The I & D group had 21 patients, and the fistulotomy group had 24 patients. Thirteen patients had low intersphincteric abscess-fistula, and seven had low transsphincteric fistulas in the I & D group. The fistulotomy group had 9 intersphincteric abscess-fistula compared with 14 low transsphincteric ones. Median duration of surgery, hospital stay, and continence at final follow-up were the same in the two groups. Three had recurrent abscess-fistula in the I & D group compared with none in the fistulotomy group (P = 0.09).

CONCLUSION

I & D alone for acute anal abscess-fistula with demonstrated internal opening showed a tendency to recurrence that did not reach a statistically significant difference compared with concurrent fistulotomy. I & D, therefore, puts only a few patients at risk for recurrence.

Ileostomy output in the early postoperative period

The high volume output of a defunctioning loop ileostomy after rectal excision and anastomosis may lead to severe dehydration and electrolyte imbalance if not properly managed. Although chronic losses may be seen, the early postoperative period remains the most hazardous with regard to acute fluid and electrolyte losses for the patient with a defunctioning ileostomy1–3. A prospective study was therefore conducted to determine the period and severity of excessive ileostomy loss.

High-repetition-rate femtosecond optical parametric oscillator based on KNbO(3)

A Ti:sapphire-pumped, high-repetition-rate, femtosecond optical parametric oscillator based on potassium niobate is described. Signal pulses as short as 90 fs have been recorded, and idler pulses as short as 105 fs have been measured. Tuning from 1.2 to 1.4 microm in the signal branch and from 1.76 to 2.2 microm in the idler branch has been achieved. Output powers as high as 300 mW have been measured at the signal wavelength.

High-repetition-rate femtosecond optical parametric oscillator based on RbTiOAsO(4)

A high-repetition-rate Ti:sapphire-pumped femtosecond optical parametric oscillator based on the new nonlinear-optical crystal RbTiOAsO(4) is described. Tuning from 1.03 to 1.3 microm in the signal branch and from 2.15 to 3.65 microm in the idler branch with powers as high as 250 mW in the signal and 200 mW in the idler is presented. The possibility of extending the tuning range beyond 3.65 microm is discussed.

Operative treatment of acetabular fractures

A retrospective review of 23 patients with acetabular fractures operated upon between January 1985 and December 1990 was conducted. Eighteen patients were available for assessment of functional outcome. Radiological results were also evaluated. The majority of the patients were male and the average age was 35 years. Three-quarters of the patients had an injury to another system. Three-quarters of the patients were operated upon within two weeks and only two patients had complications directly related to the operation. Radiological result was excellent or good in 61%, fair in 22%, and poor in 16% of the patients. Functional score was excellent or good in 72%, fair in 16% and poor in 11%. In summary, operative treatment of acetabular fracture is a safe and acceptable method of managing displaced acetabular fractures.

Thermal lens spectrometry using a broadly tunable optical parametric oscillator

We present a computerized optical parametric oscillator that is capable of continuous tuning from approximately 420 nm to 2 µm for spectroscopic and spectrometric applications. This system allows any selected wavelength within the tuning range to be reached directly and quickly. We demonstrate the versatility of the system by measuring the entire visible (450-690-nm) thermal lens spectrum of NO(2) with a continuous scan.