Does surgical repair of a rectocele improve rectal emptying?

PURPOSE

This study was undertaken to assess results of surgical repair of rectocele and to identify possible determinants of outcome from patient's history and preoperative defecography. Another aim was to evaluate how surgery affects rectal evacuation.

METHOD

Thirty-four women with constipation and rectal emptying difficulties underwent surgery with a transanal technique. A preoperative defecography was performed in each patient. They were followed up after a median of 10 (range, 2-60) months with a questionnaire (n = 34) and a defecography (n = 31). Computer-based image analysis of defecographies was used to evaluate rectal evacuation.

RESULTS

In 27 patients (79 percent), the result of surgery was good with subjectively improved emptying. The need for vaginal or perineal digitation preoperatively was related to a good result (P < 0.05), whereas a previous hysterectomy (P < 0.01) and a large rectal area on defecography (P < 0.01) related to a poor result. Preoperative use of enemas, motor stimulants, or several types of laxatives also related to a poor outcome (P < 0.05). Surgical treatment resulted in reduction of the rectocele (P < 0.001), an elevated position of the anorectal junction (P < 0.05), and improved rectal evacuation on defecographies (P < 0.001).

CONCLUSIONS

Surgical repair reduces the size of the rectocele and improves rectal emptying. These changes are accompanied by a symptomatic improvement in the majority of patients. Preoperative patient data and defecography may help in selecting patients for surgery.

Prognosis after surgery in patients with incurable rectal cancer: a population-based study

In a defined population between 1973 and 1992 151 patients with irresectable metastatic or local rectal cancer were identified. Eighty-one patients underwent resection of the primary tumour (group 1) whereas the primary tumour was left in situ in 70 patients (group 2). During the same time period, 444 patients underwent curative resection. The median survival was 7.5 months in group 1, and 3.5 and 1.9 months for surgically and non-surgically treated patients respectively in group 2. A colostomy for intestinal obstruction became necessary in 12 per cent of the patients with a retained primary tumour. Bilateral hepatic involvement, abnormal liver function test results, peritoneal growth or abdominal lymph node metastases correlated with a short survival (P < 0.01). These results support a selective approach to patients with incurable rectal cancer.

Factors influencing recurrence in Crohn's disease. An analysis of a consecutive series of 353 patients treated with primary surgery

PURPOSE

This study was undertaken to investigate the factors that influenced the risk of symptomatic recurrence in patients with Crohn's disease who were treated with primary resective surgery.

METHODS

Data regarding age, gender, time from diagnosis to surgery, medication, preoperative infectious complications, laboratory values, emergency/elective surgery, location and extent of disease, and resection margins were analyzed in relation to recurrence in 353 patients who were undergoing a "curative" resection in 1969 to 1986.

RESULTS

Univariate analyses showed a higher risk of recurrence in women with ileal and ileocolonic disease than in men (P < 0.05), in patients with ileocolonic disease compared with those with isolated ileal disease (P < 0.05), and in ileal disease patients with an increased disease extent (P < 0.05). In a multivariate analysis performed on patients with ileal disease, increased disease extent, limited resection on the colonic side, and referral from other hospitals were three independent variables that indicated an increased risk of recurrence (P < 0.05). Length of disease-free resection margins did not influence the risk of recurrence either in univariate or in multivariate analysis (P > 0.05).

CONCLUSIONS

Disease extent has prognostic value regarding the risk of symptomatic recurrence in Crohn's disease, whereas the length of resection margins does not influence the risk of relapse. These results favor a conservative approach, particularly in patients with extensive disease.

A pilot study of factors influencing bowel function after colorectal anastomosis

PURPOSE

This study was undertaken to assess subjective bowel function after anterior resection and to search for clinical characteristics that might affect the functional results.

METHODS

A total of 70 patients answered a questionnaire concerning bowel function a median of 65 months after anterior resection, and 40 patients responded to the same questionnaire a median of 60 months after colonic resection.

RESULTS

Median frequency of bowel movement per 24 hours was two (range, 0.2-9) after rectal resection and one (range, 0.4-6) after colonic resection (P < 0.001). Incontinence for loose stools (P < 0.01), need to wear a pad (P < 0.05), and need to return to the toilet after defecation (P < 0.05) was more common in the rectal resection group. In the latter group, advanced age, use of descending or transverse colon for anastomosis, and large amount of intraoperative bleeding was associated with fecal incontinence (P < 0.05). Preoperative radiotherapy was correlated with a high bowel frequency (P = 0.003).

CONCLUSIONS

These data indicate that alterations of subjective bowel function frequently observed after colorectal anastomosis may be affected by both surgical technique and adjuvant radiotherapy.

Evaluation of a questionnaire in the assessment of patients with faecal incontinence and constipation

BACKGROUND

A self-reported questionnaire may be a useful instrument in assessing patients with faecal incontinence and constipation.

METHODS

Reliability, discrimination, validity, and sensitivity were evaluated in 16 control subjects 36 patients with faecal incontinence, and in 38 with constipation. The reliability was measured by a test-retest procedure (kappa (kappa) statistics or Spearman rank test), and validity by comparing the questionnaire and a diary. Discrimination was assessed by comparing the patient groups with the controls, and sensitivity by comparing selected answers before and after treatment.

RESULTS

Overall reliability (faecal incontinence group, mean kappa = 0.57; constipation group, mean kappa = 0.60; controls, mean kappa = 0.95) and validity were judged acceptable. In the incontinence group occurrence of faecal incontinence per se was reproducible (kappa = 0.66), as was the need to wear a pad (kappa = 0.85). Stool frequency, percentage toilet time spent straining and digitation was reproducible in patients with constipation (kappa = 0.80, r = 0.56; p < 0.001, kappa = 0.83 respectively). Several items distinguished both patient groups from healthy controls (p < 0.05 to p < 0.001). Sensitivity to surgical treatment was seen in several items in both patient groups.

CONCLUSIONS

The questionnaire appears to be a valid measure of symptoms in faecal incontinence and constipation with sufficient discriminatory capacity.

Long-term results of anterior levatorplasty for fecal incontinence. A retrospective study

PURPOSE

To review the long-term results of anterior levatorplasty for fecal incontinence.

METHODS

Fifty-four women with obstetric trauma and 31 with idiopathic incontinence responded to a questionnaire 1.5 to 18.5 (median, 8.5) years after anterior levatorplasty. Results were classified as excellent, good, fair, or poor.

RESULTS

An excellent or good result was reported in 40 of 54 (74 percent) patients with an obstetric injury and in 14 of 31 (45 percent) patients in the idiopathic group (P < 0.01). The presence of a cloaca (P < 0.05) and a young age (P < 0.05) were associated with a favorable outcome in the obstetric and idiopathic group, respectively. Length of follow-up and preoperative severity of incontinence were not significantly related to outcome.

CONCLUSIONS

This study suggests that every second patient undergoing anterior levatorplasty for fecal incontinence has a successful result that is sustained in the long term. Obstetric trauma, presence of a cloaca, and young age are associated with a successful outcome.

Monitoring palliative chemotherapy in advanced gastrointestinal cancer using serial tissue polypeptide specific antigen (TPS) measurements

Tissue polypeptide antigen specific (TPS) was analysed in serum taken prior to chemotherapy in 90 patients with advanced gastrointestinal cancer and prior to every treatment course in 68 of these patients in order to explore whether serial tumour marker measurements can be of importance in monitoring patients treated with palliative chemotherapy. Elevated TPS levels were seen in 83/90 (92%) patients (48/52 colorectal, 9/9 pancreatic, 9/11 biliary, 17/18 gastric). Baseline TPS level correlated with performance status, tumour response and survival. Based upon the change in TPS levels after the first two courses in relation to baseline, a decrease by >50% had a high sensitivity for a favourable treatment outcome (partial remission and prolonged stationary disease (90%) or a subjective response (100%)), whereas the specificity was lower (72% and 73% respectively). A similar result was seen when the TPS levels were analysed at the time of the response evaluation after 2 months (sensitivity 91 and 95%, specificity 74 and 75% for an objective or subjective response respectively). In 7 out of 15 patients with an initially favourable outcome, an increase in TPS levels of >50% at two occasions was seen 8-20 weeks prior to clinical disease progression. In advanced gastrointestinal cancer serial TPS measurements can with high accuracy early identify patients who will not benefit from the treatment. On the other hand, a response must be confirmed using other methods in the presence of a decrease, since this was also seen in non-responding patients.

Different intravenous administration techniques for 5-fluorouracil. Pharmacokinetics and pharmacodynamic effects

The pharmacokinetics after 20 min intravenous infusion or a 2 min bolus (push) injection of 5-fluorouracil (500 mg/m2) were studied in 14 colorectal cancer patients. Treatment effects and toxicity related to the administration technique of 5-fluorouracil were retrospectively analysed in 198 colorectal cancer patients. The AUC after bolus injection was 6158 +/- 874 micromol/l*min compared to 3355 +/- 428 micromol/l*min after short-time infusion of 5-fluorouracil (p < 0.01). The mean peak-level after bolus injection was 341 +/- 34 microM versus 161 +/- 17 microM after a short-time infusion (p < 0.01). Patients receiving bolus injections had significantly better treatment result (32% partial remission) than patients receiving infusion (10% partial remissions, p < 0.001). Toxic side-effects were more frequently encountered after bolus injection but subjective improvement was also more frequently experienced by these patients. Bolus 5-fluorouracil push injection rather than a short-time infusion appears to be the more efficient administration technique.

Selective sensitivity of solid tumors to suramin in primary cultures of tumor cells from patients

The antineoplastic activity of suramin is currently the subject of clinical trials. We therefore used the semi-automated fluorometric microculture cytotoxicity assay (FMCA) to evaluate the cytotoxicity of suramin in vitro in primary cultures of cells from patients with hematological or solid tumors. The activity patterns of some standard cytotoxic agents were included for comparison. A total of 159 samples were tested using continuous drug exposure. Suramin showed relatively high activity against solid tumors, with colorectal, adrenal and kidney carcinomas being the most sensitive, whereas hematological malignancies were more resistant. Suramin and standard drugs showed very low cross-resistance. The results indicate that suramin is differentially active against some solid tumors with comparatively little activity against hematological tumors. The study provides an experimental motive for evaluation of suramin therapy in patients with solid tumors and exploration of less toxic suramin analogues.

Free radicals, anticonvulsants, and the neuronal ceroid-lipofuscinoses

The relationship between free radicals and scavenger enzymes, and the disorders called the neuronal ceroid-lipofuscinoses, has long been an argumentative one. Recent evidence would seem to support the fact that such a relationship might exist but that it is indirect. The relationship does not seem due to an inborn error of free radical scavenger enzyme metabolism. Anticonvulsants play a role, as they influence free radical generating systems. At this juncture, no one has studied the relationship of anticonvulsant therapy, neuronal ceroid-lipofuscinosis, and the free radical-scavenging enzyme system, and their interplay. We have studied a large number of patients with epilepsy who are on either monotherapeutic or polytherapeutic regimens of most of the common anticonvulsants. We have found excessive free radical production in many of these patients, ranging from minor effects in the simpler anticonvulsants when used monotherapeutically, to more complex changes in polytherapeutic combinations. Likewise, we have found subtle and inconsistent findings in the free radical-scavenging enzyme system in a variety of examples of neuronal ceroid-lipofuscinosis. When refractory seizure disorders stimulate the vigorous use of polytherapy with a variety of free radical-facilitating anticonvulsants, free radical production becomes deleterious. Likewise, in certain types of neuronal ceroid-lipofuscinosis, polypharmacy with anticonvulsants, by enhancing the production of free radicals or suppressing scavenging enzymes, tends to be deleterious and induces a worsening in the disease process.

Anastomotic breaking strength and healing of anastomoses in rat intestine with and without chronic radiation damage

OBJECTIVE

To assess the influence of chronic radiation damage on anastomotic healing in the small bowel in rats.

DESIGN

Controlled laboratory study.

SETTING

University hospital, Sweden.

MATERIAL

90 male Sprague-Dawley rats.

INTERVENTIONS

A short segment of the distal ileum was exteriorised and irradiated with a single dose (experimental group, n = 45) or exposed only (control group, n = 45). Twenty weeks later resection and anastomosis were done within this segment using 7/0 polypropylene.

MAIN OUTCOME MEASURES

The anastomotic breaking strength, the amount of perianastomotic hydroxyproline, and the number of anastomotic complications.

RESULTS

The breaking strength and the amount of perianastomotic hydroxyproline were higher in the irradiated than in the non-irradiated group. In contrast, anastomotic complications were significantly more common in irradiated animals.

CONCLUSION

Anastomotic complications in irradiated intestine are not related to the amount of perianastomotic collagen or to breaking strength.

Relationships between defecographic findings, rectal emptying, and colonic transit time in constipated patients

The relations between defecographic findings, rectal emptying, and colonic transit time were analysed in 80 constipated patients (median age 49 years, range 22-87). Patients were classified into three clinically defined groups (slow transit, outlet obstruction, and a mixed group). Rectal evacuation was evaluation was evaluated by computer-based area calculation. There were no differences in defecographic findings except that evacuation was less efficient in the slow transit group compared with the mixed group (p < 0.01) and with the outlet obstruction group (P < 0.05). Transit time was prolonged in the slow transit and mixed groups compared with the outlet group (p < 0.001). Prominent impression of the puborectalis muscle during straining and the size of a rectocoele correlated with rectal emptying (p < 0.01). Perineal descent, anorectal angles, enterocoele, or intussusception were not significantly related to emptying. Prominent impression of the puborectalis muscle (p < 0.05) and impaired rectal emptying (p < 0.05) were more frequent in patients with prolonged transit time (six or more days). There was no significant correlation between transit time and rectal evacuation in the total study population. There was, however, an inverse relation between these variables (r = 0.40, p < 0.02) when all patients who claimed infrequent defecation (two or fewer/week) were analysed separately. These results did not confirm a direct relation between rectal evacuation and colonic transit time in constipated patients overall. The results are consistent with the suggestion that impaired colonic function may develop secondary to outlet obstruction in some patients.

Anorectal manovolumetry in the diagnosis of fecal incontinence

PURPOSE

This study was designed to investigate rectal reservoir function and anal pressures in patients with fecal incontinence using anorectal manovolumetry and to evaluate the reproducibility of the investigation.

METHODS

Forty-eight patients with fecal incontinence were investigated with respect to anal pressures and rectal volume changes and sensibility in response to stepwise increased rectal pressures (5-60 cm of H2O). Patients with known rectal wall diseases were excluded. Results were compared with those of 25 control subjects investigated in a similar manner. In ten individuals in the latter group, investigation was repeated after 5 minutes and 24 hours.

RESULTS

Resting pressure (RP), squeezing pressure (SP), and the difference between SP and RP was lower in patients than in controls (P < 0.0001). There was no significant difference between patients and controls concerning rectal sensibility or compliance (P > 0.05), but there was a correlation between RP and rectal compliance (r = 0.25; P < 0.05) and between SP and rectal compliance (r = 0.30; P < 0.01). There was good reproducibility of RP and SP after five minutes (r = 0.88-0.92; P < 0.001). The day-to-day variation was larger for RP (r = 0.52; P > 0.05) compared with SP (r = 0.89; P < 0.001). Rectal compliance at 40 cm of H2O was reproducible after 5 minutes (r = 0.98; P < 0.0001) and 24 hours (r = 0.88; P < 0.01).

CONCLUSIONS

These results indicate that the primary defect in incontinent patients is a sphincter dysfunction. Any reduction in rectal compliance is likely to be a secondary phenomenon.

Functional results after seton treatment of high transsphincteric anal fistulas

OBJECTIVE

To evaluate the functional outcome after seton treatment of high transsphincteric anal fistulas.

DESIGN

Retrospective study.

SETTING

University hospital, Sweden.

SUBJECTS

29 patients (8 women, mean age 46, range 25-71) with high transsphincteric anal fistulas 1983-1992.

INTERVENTIONS

Setons were inserted in the anal fistulas in all patients.

MAIN OUTCOME MEASURES

Anal continence evaluated by a questionnaire a mean of 46 months postoperatively. Clinical data were collected from the patients' records.

RESULTS

All four patients with inflammatory bowel disease had some incontinence. Of the remaining 25 patients, 11 (44%) complained of incontinence and 2 (8%) developed recurrent fistulas. Incontinence was more common when the seton was tightened at the last procedure (7/9) compared with those in which the tissue enclosed by the seton was divided (4/16, p = 0.03). No other preoperative or operative characteristic significantly influenced the risk of incontinence.

CONCLUSION

Incontinence is common after seton treatment of high transsphincteric anal fistulas. The risk seems to be higher when the muscle remains viable after a period of seton treatment.

Characterization of the alloreactivity and anti-leukemia reactivity of cord blood mononuclear cells

It has been suggested that cord blood T cells may be less able to mediate GVHD than marrow-derived T cells due to their naive status. A decreased potential for GVHD may be advantageous for allogeneic transplant, but this benefit might be counteracted by loss of the GVHD associated graft-versus-leukemia (GVL) effect. The GVL potential of cord blood could be doubly compromised since cord blood NK cell activity is also decreased. To assess these issues we have performed extensive comparative functional and immunophenotypic evaluations of cord and adult mononuclear cells. We found a somewhat reduced alloproliferative, allostimulatory and allocytolytic capacity of cord blood mononuclear cells in bulk assays but not by limiting dilution assays. Immunophenotyping revealed no significant differences in the proportion of major lymphocyte subsets with the exception of the previously recognized predominance of CD45RA+ cells in both CD4 and CD8 cord blood T cells. Cord blood T cells expressed normal percentages of the cellular adhesion molecules, CD11a, CD18 and LFA-3; however, the antigen density of each of these molecules was less than that found on adult T cells. Fewer resting cord blood T cells expressed CD54, the ligand for LFA-1. Cord blood B cells and monocytes expressed normal levels of HLA-class I and HLA class II DR, DP and DQ antigens, suggesting that the decreased expression of cellular adhesion molecules or their receptors rather than a decrease in expression of HLA might have contributed to the lower alloreactivity of cord blood. Although the percentages of NK cells and NK cell subsets in adult and cord blood were similar our data confirmed that cord blood has very low NK lytic activity. In contrast, LAK activity was much more readily induced in cord blood compared with adult PBMC, a finding which could be explained in part by a higher frequency of LAK precursors and a more rapid expansion of NK cells in response to culture with medium containing of NK cells in response to culture with medium containing IL-2. Cord blood LAK cells were readily able to lyse fresh leukemia targets from patients with ALL, AML and CML. The data indicate that although the alloreactive potential of cord blood cells may be somewhat decreased, it is not absent and must be considered a factor in cord blood transplants. LAKp with the potential to lyse leukemia are present in increased numbers in cord blood and might contribute to the GVL effect of a cord blood transplant.

Cost-effectiveness of palliative chemotherapy in advanced gastrointestinal cancer

BACKGROUND

Chemotherapy may relieve tumor-related symptoms, may improve quality of life and prolong survival in advanced gastrointestinal cancer. The extent of such improvements is unclear despite the extensive use of this treatment modality, and there are no studies concerning the economic cost of any gain achieved in the quantity and quality of life by chemotherapy.

PATIENTS AND METHODS

Between January 1991 and May 1992, 61 patients with inoperable cancer (18 gastric, 22 pancreatic or biliary, and 21 colorectal) were randomized to either primary chemotherapy in addition to best supportive care or to best supportive care. Chemotherapy was allowed in the latter group if the supportive measures did not achieve palliation. All economic costs for medical care were prospectively recorded, and marginal cost-effectiveness analyses were performed.

RESULTS

More patients in the primary chemotherapy group (19/33, 58%) had improved/prolonged high quality of life (QoL-patient, minimum duration 4 months) than in the best supportive care group (8/28, 29%, p < 0.05). Overall survival and quality-adjusted survival were significantly longer in the primary chemotherapy group (median 9 vs. 4 months, p < 0.05), and median 7 vs. 2 months, p < 0.05, respectively). When analysed by cancer site, survival was significantly prolonged in gastric cancer patients (median 10 vs. 4 months, p < 0.02), but not in colorectal (median 12 vs. 6 months, p = 0.1) and pancreatic-biliary cancer patients (median 8 vs. 5 months, p = 0.8). The average cost for all medical care was approximately 50% higher in the primary chemotherapy group, but the average cost per day was the same in the two groups. Hospitalization accounted for most of the costs in both groups. The incremental costs per gained year of life was SEK 166,400 ($21,300), per gained quality-adjusted year of life SEK 157,200 ($20,200), and per QoL-patient SEK 160,300 ($20,600). These costs were lower for gastric and colorectal cancer patients, and much higher for pancreatic-biliary cancer patients.

CONCLUSIONS

The results of this study suggest that palliative chemotherapy is cost-effective in patients with advanced gastric and colorectal cancer. Knowledge about survival and quality of life benefits is still limited in patients suffering from gastric and pancreatic-biliary cancer.

Laparoscopic suture rectopexy

PURPOSE

This article describes a technique for laparoscopic suture rectopexy and assesses the postoperative results.

METHODS

The rectum was fixed to the presacral fascia with five to six sutures. The procedure was performed using a laparoscope in four patients.

RESULTS

There were no postoperative complications. In one patient a large enterocele was observed during the operation. This patient developed a recurrence about one month postoperatively.

CONCLUSION

Laparoscopic suture rectopexy might be an alternative to open rectopexy for patients with isolated rectal prolapse.

Functional anatomy of the head-neck movement system of quadrupedal and bipedal mammals

This biomechanical investigation quantified the range of motion of the different articulations of the head-neck ensemble in man, monkeys, cats, rabbits and guinea pigs. Radiography and dissections were used to establish the degrees of freedom of the system. The erect posture and rigidity of the cervical spine in mammalian vertebrates are possible because the degrees of freedom of the movements of the cervical and upper thoracic vertebrae in passive ranges of motion are asymmetric, and thus significantly restricted, when judged from the resting position. The total range of motion at the atlanto-occipital articulation varies between species. It is approximately 90 degrees-105 degrees in the quadrupedal mammals tested, and only 11 degrees or 13 degrees, respectively, in humans and monkeys. When at rest, bipeds and quadrupeds hold the atlanto-occipital articulation and the upper cervical joints (C1/C2, C2/C3) in a flexed attitude. The total range of motion at the cervicothoracic junction (C6-T2) is approximately 6 degrees-80 degrees in all vertebrates investigated (quadrupeds and bipeds). At rest, the vertebral articulations that form the cervicothoracic junction are held in their extreme extended positions in quadrupeds and monkeys. In man, the vertebrae of the lower cervical spine are kept at a midposition between maximal flexion and maximal extension. This latter observation may be related to the permanent bipedalism of humans. Collectively, our data indicate that biomechanical constraints such as bone structures (e.g. specifically shaped articular processes) and ligaments may maintain the intrinsic configuration and self-supporting structure of the cervical spine. Furthermore, the specialised structures in the cervical joints allow movements more or less in particular planes of space, and thus biomechanical constraints limit the number of possible solutions as to how an animal can perform a given orientating head movement. Although we have not entirely clarified the functional implications for head movement control of the different sagittal-plane ranges of motion in vertebrates, we hypothesise that different mechanical requirements relating to the influence of gravity have caused the observed differences between the investigated bipedal and quadrupedal mammals.

The orientation of the cervical vertebral column in unrestrained awake animals. II. Movement strategies

Previously we demonstrated a stereotyped resting posture of the head-neck arrangement in a number of vertebrates: the cervical vertebral column is oriented vertically to form one portion of the partial S-shaped configuration of the entire spine. The present investigation quantified the various strategies of head-neck movements employed by different mammalian species (human, monkeys, cats, rabbits and guinea pigs) using cineradiography. At rest, bipeds and quadrupeds hold their heads at the extreme point of flexion of the passive atlanto-occipital range of motion. In this posture, the horizontal semicircular canals are tilted upward from earth horizontal by 5 to 10 degrees and roughly parallel the plane determined by the two obliquus capitis posterior muscles. Furthermore, at this head position, the utricular maculae become oriented earth-horizontally. In quadrupedal animals, head-neck movements in the sagittal plane result from movement at the atlanto-occipital articulation (head/C1) and at the multi-articular cervico-thoracic junction (C6-Th3). Only very small flexion/extension movements occur within the body of the cervical vertebral column (C2-C5). Lowering the head from the resting position is only possible by flexion at the C6-Th3 vertebrae. Raising of gaze from the resting position is only possible by extension of the head at the atlanto-occipital articulation. By contrast, sagittal plane head movements in bipeds are largely confined to the cervico-thoracic junction. This is related to a significantly reduced range of motion of the atlanto-occipital articulation. In monkeys and humans, it range of motion is about 13 and 8-11 degrees, respectively, compared to 105 degrees in rabbits. Our cineradiographic data demonstrated different strategies for head movements in the sagittal plane between quadrupeds and bipeds. At one end of the spectrum, in the case of rabbits, there was no systematic relationship between head and neck orientation. Rabbits stabilized head posture by using the head-neck structure in a parallelogram fashion, which resulted in head posture being largely independent of cervical vertebral column orientation. In monkeys and humans, however, orientation of the head depended almost entirely on the orientation of the cervical vertebral column. In such case, head movements in the sagittal plane almost exclusively relied on the positioning of the cervico-thoracic junction. These different strategies again correlate with the different ranges of motion of the atlanto-occipital articulation. We suggest that vertebrates use mechanical constraints and preferred planes of action for head-neck movement control to simplify sensory-motor transformations subserving motor control and plasticity and to minimize neuronal operations.

Computed tomography of experimental liver metastases using an iodinated hepatocyte-specific lipid emulsion. A correlative study in the nude rat

RATIONALE AND OBJECTIVES

A hepatocyte-specific iodinated lipid emulsion, NRI 757, was used for detection of experimental hepatic metastases.

MATERIALS AND METHODS

The study was performed in a correlative model of multiple hepatic metastases from a human colonic cancer implanted in the nude rat.

RESULTS

After intravenous injection, normal liver parenchyma remained enhanced for several hours, whereas the uptake in hepatic metastases was negligible. A liver-to-lesion contrast of 45 Hounsfield units (HU) was obtained at a dose of 1 mL NRI 757/kg body weight (BW). In a lesion-by-lesion analysis of 177 metastases ranging in size from 1 to 32 mm, the mean +/- standard deviation overall detection rate for native scanning and contrast-enhanced scanning in vivo and post mortem, 20 +/- 0.4%, 53 +/- 5.2%, and 55 +/- 4.0%, respectively and 28%, 84%, and 82%, retrospectively. When metastatic size also was considered, for native scanning the maximum detection rate of 61% was reached for 8- to 10-mm lesions, whereas for contrast-enhanced computed tomography scanning, 100% of the 5- to 7-mm lesions and 42% of the 1- to 2-mm nodules were detected.

CONCLUSION

The use of NRI 757 improved the diagnostic yield considerably.

Experimental colonic healing in relation to timing of 5-fluorouracil therapy

In an experimental study resembling clinical use of adjuvant 5-fluorouracil (5-FU) treatment of colorectal carcinoma, 97 male Wistar rats were operated on with a standardized left colonic resection. Treatment was given as a daily intraperitoneal injection. The animals were randomized to one of four groups: early treatment with 5-FU 20 mg/kg or saline 0.1 mol/l from the day of operation to day 7 after operation, and delayed treatment with 5-FU 20 mg/kg or saline 0.1 mol/l from the third day after operation to the day before killing. The animals were killed in groups on day 7 or 10 after operation. In the group receiving early 5-FU treatment there was an increased rate of anastomotic complications (seven of 26) compared with none in the control or delayed 5-FU groups. The anastomotic breaking strength in animals having early 5-FU treatment (day 7, median 1.45 (range 0.20-2.95) N; day 10, median 1.80 (range 0.95-3.20) N) was significantly lower than that in controls on both day 7 (median 3.20 (range 2.50-3.80)N) and day 10 (median 3.20 (range 2.20-3.60)N). In the delayed 5-FU treatment group anastomotic breaking strength did not differ from that in controls. Colonic healing was not impaired when intraperitoneal 5-FU treatment was started on day 3 after operation, whereas immediate postoperative administration of 5-FU had a detrimental effect on wound healing.

The influence of early postoperative intraperitoneal chemotherapy on human wound healing

Cell ingrowth, hydroxyproline accumulation, and mRNA expression of collagen I were measured in two polytetrafluoroethylene grafts implanted subcutaneously at the time of colorectal cancer surgery to evaluate the influence of early postoperative chemotherapy on human wound healing. Eleven patients treated with intraperitoneal 5-fluorouracil and intravenous folinic acid Days 1-6 after operation were compared with 15 patients who underwent surgery alone. At 1 week, chemotherapy-treated patients had accumulated less hydroxyproline (mean 0.35 +/- 0.33 micrograms/cm) compared with untreated patients (mean 0.73 +/- 0.37 micrograms/cm, P < 0.05). By 2 weeks, the hydroxyproline content had increased sixfold in the chemotherapy group (P < 0.01) and threefold in the nonchemotherapy group (P < 0.01) and there was no difference between the groups. Cell and connective tissue ingrowth and total RNA content did not differ between the groups at any point in time, but at 1 week the mRNA expression of collagen I was higher in the chemotherapy group (P < 0.05). These results indicate that collagen accumulation in human subjects is reduced during a short course of postoperative chemotherapy and normalizes after the end of treatment.