Morbidity associated with the immediate vertical rectus abdominus myocutaneous flap reconstruction after radical pelvic surgery.

AIM: Patients who undergo radical pelvic surgery often have problems with perineal wound healing and pelvic collections. While there is recognition of the perineal morbidity, there also remains uncertainty around the benefit of vertical rectus abdominus myocutaneous (VRAM) flaps due to the balance between primary healing and the complications associated with this form of reconstruction. This study aimed to evaluate factors associated with significant flap and donor site related complications following VRAM flap reconstruction for radical pelvic surgery. METHOD: A retrospective analysis of VRAM flap related complications was undertaken from prospectively maintained databases for all patients undergoing radical pelvic surgery (2001- 2017) in two cancer centres. RESULTS: In all, 154 patients were identified [median age 62 years (range 26-89 years), 80 (52%) men]. Thirty-three (21%) patients experienced significant donor or flap related complications. Major complications (Clavien-Dindo ≥ 3) related to the abdominal donor site occurred in nine (6%) patients, while those related to the flap or perineal site occurred in 28 (18%) patients. Only smoking (P = 0.003) and neoadjuvant radiotherapy (P = 0.047) were associated with the development of significant flap related complications on univariate analysis. Flap related complications resulted in a significantly longer hospital stay (P < 0.001). CONCLUSION: Careful patient selection is required to balance the risks vs the benefits of VRAM flap reconstruction. Immediate VRAM reconstruction in patients undergoing radical pelvic surgery can achieve early healing and stable perineal closure; it has a low but significant morbidity. Major flap related complications are significantly associated with smoking status and neoadjuvant radiotherapy and result in a prolonged length of hospital stay.

Motor IOR revealed for reaching.

Inhibition of return (IOR) is a spatial phenomenon that is thought to promote visual search functions by biasing attention and eye movements toward novel locations. Considerable research suggests distinct sensory and motor flavors of IOR, but it is not clear whether the motor type can affect responses other than eye movements. Most studies claiming to reveal motor IOR in the reaching control system have been confounded by their use of peripheral signals, which can invoke sensory rather than motor-based inhibitory effects. Other studies have used central signals to focus on motor, rather than sensory, effects in arm movements but have failed to observe IOR and have concluded that the motor form of IOR is restricted to the oculomotor system. Here, we show the first clear evidence that motor IOR can be observed for reaching movements when participants respond to consecutive central stimuli. This observation suggests that motor IOR serves a more general function than the facilitation of visual search, perhaps reducing the likelihood of engaging in repetitive behavior.

Motor inhibition of return can affect prepared reaching movements.

Inhibition of return (IOR) is a widely studied phenomenon that is thought to affect attention, eye movements, or reaching movements, in order to promote orienting responses toward novel stimuli. Previous research in our laboratory demonstrated that the motor form of saccadic IOR can arise from late-stage response execution processes. In the present study, we were interested in whether the same is true of reaching responses. If IOR can emerge from processes operating at or around the time of response execution, then IOR should be observed even when participants have fully prepared their responses in advance of the movement initiation signal. Similar to the saccadic system, our results reveal that IOR can be implemented as a late-stage execution bias in the reaching control system.

Saccadic inhibition of return can arise from late-stage execution processes.

Inhibition of return (IOR) is thought to improve the efficiency of visual search behaviour by biasing attention, eye movements, or both, toward novel stimuli. Previous research suggests that IOR might arise from early sensory, attentional or motor programming processes. In the present study, we were interested in determining if IOR could instead arise from processes operating at or during response execution, independent from effects on earlier processes. Participants made consecutive saccades (from a common starting location) to central arrowhead stimuli. We removed the possible contribution of early sensory/attentional and motor preparation effects in IOR by allowing participants to fully prepare their responses in advance of an execution signal. When responses were prepared in advance, we continued to observe IOR. Our data therefore provide clear evidence that saccadic IOR can result from an execution bias that might arise from inhibitory effects on motor output neurons, or alternatively from late attentional engagement processes.

Routine colonoscopy following acute uncomplicated diverticulitis.

BACKGROUND: The evidence supporting current recommendations that the colon should be evaluated following an initial episode of acute diverticulitis is poor. The aim of this study was to clarify whether acute uncomplicated diverticulitis is a valid indication for subsequent colonoscopy/computed tomography (CT) colonography. METHODS: This was a retrospective longitudinal study of patients with an initial presentation of acute uncomplicated diverticulitis on the basis of CT criteria, at a single institution between January 2004 and December 2008. RESULTS: A radiological diagnosis of acute uncomplicated diverticulitis was made in 292 patients. Some 205 patients underwent subsequent colonic evaluation or had undergone colonoscopy/CT colonography within the preceding 2 years. Colorectal polyps were present in 50 patients (24·4 per cent). Twenty patients (9·8 per cent) had hyperplastic polyps and 19 (9·3 per cent) had adenomas. Eleven patients (5·4 per cent) had advanced colonic neoplasia, including one (0·5 per cent) with a colorectal cancer. One patient had inflammatory bowel disease (IBD). The patients with colorectal cancer and IBD had clinical indicators that independently warranted colonoscopy. None of the 87 patients who did not undergo colonic evaluation had a diagnosis of colorectal cancer registered with the New Zealand Cancer Registry. CONCLUSION: The yield of advanced colonic neoplasia in this cohort was equivalent to, or less than that detected on screening asymptomatic average-risk individuals. In the absence of other indications, subsequent evaluation of the colon may not be required to confirm the diagnosis of diverticulitis.

Colonic perforation following blunt trauma to an inguinal hernia.

External forces that may appear trivial in the setting of blunt abdominal trauma can cause significant hollow viscus injury when applied directly to an inguinal hernia. We report a very rare case of colonic perforation following a direct blow to an inguinal hernia sustained during a rugby union match and review the relevant literature.

Internal-external percutaneous transhepatic biliary drainage for malignant biliary obstruction: a retrospective analysis.

When percutaneous transhepatic biliary drainage (PTBD) is required for the management of malignant biliary obstruction, the local policy favours the use of internal-external drains. Regular planned drain exchanges are scheduled, and patients have open access back into the system to minimise complications. The aim of this study was to evaluate the success and complication rate of this method for the palliation of malignant biliary obstruction. The hospital records of 43 consecutive patients who underwent PTBD for malignant biliary obstruction at a single institution between 1 February 2004 and 31 January 2006 were reviewed. Outcomes were examined until January 2008. Biliary decompression was achieved in all 43 patients. The level of obstruction was defined as distal in 24 patients and perihilar in 19 patients. There was one procedure-related death. There were 91 routine outpatient drain exchanges performed at a median interval of 45 (range 21-64) days. Overall, 24/43 patients encountered 80 discrete complications related to biliary drainage. Fifty-two non-scheduled drain exchanges (accounting for 65% of all complications) were performed on an outpatient basis. Fourteen patients were readmitted on a median of one (range 1-3) occasion for a median duration of 3 (range 1-12) days. Median survival was 71 (range 7-850) days. PTBD can be performed with low mortality, but long-term morbidity remains high despite an aggressive approach to maintaining biliary patency. Providing patients with an open-access service means the majority of complications can be dealt with on an outpatient basis.

Influence of body heat content on hand function during prolonged cold exposures.

We examined the influence of 1) prior increase [preheating (PHT)], 2) increase throughout [heating (HT)], and 3) no increase [control (Con)] of body heat content (H(b)) on neuromuscular function and manual dexterity of the hands during a 130-min exposure to -20 degrees C (coldEx). Ten volunteers randomly underwent three passive coldEx, incorporating a 10-min moderate-exercise period at the 65th min while wearing a liquid conditioning garment (LCG) and military arctic clothing. In PHT, 50 degrees C water was circulated in the LCG before coldEx until core temperature was increased by 0.5 degrees C. In HT, participants regulated the inlet LCG water temperature throughout coldEx to subjective comfort, while the LCG was not operating in Con. Thermal comfort, rectal temperature, mean skin temperature, mean finger temperature (T(fing)), change in H(b) (DeltaH(b)), rate of body heat storage, Purdue pegboard test, finger tapping, handgrip, maximum voluntary contraction, and evoked twitch force of the first dorsal interosseus muscle were recorded. Results demonstrated that, unlike in HT and PHT, thermal comfort, rectal temperature, mean skin temperature, twitch force, maximum voluntary contraction, and finger tapping declined significantly in Con. In contrast, T(fing) and Purdue pegboard test remained constant only in HT. Generalized estimating equations demonstrated that DeltaH(b) and T(fing) were associated over time with hand function, whereas no significant association was detected for rate of body heat storage. It is concluded that increasing H(b) not only throughout but also before a coldEx is effective in maintaining hand function. In addition, we found that the best indicator of hand function is DeltaH(b) followed by T(fing).

Time course analysis of closed- and open-loop grasping of the Müller-Lyer illusion.

The authors investigated whether the early or later stages of closed-loop (CL) and open-loop (OL) grasping movements were differentially influenced by the Müller-Lyer (ML) illusion. Participants (N = 21) reached out and grasped small (5 cm) and large (7 cm) objects embedded within fins-in and fins-out ML configurations. Grasping time (GT) was normalized, and absolute grip aperture (GA) as well as scaled illusion effects were computed at 20%, 40%, 60%, and 80% of GT. The results indicated that CL trials were refractory to the illusory array (i.e., from 20% to 80% of GT), whereas OL trials were influenced by the ML figure during that same time. Those findings suggest that CL trials were supported by unitary and metrical visual information, whereas OL trials were entirely supported by perception-based visual information.

Delayed grasping of a Müller-Lyer figure.

Grasping movements are more sensitive to the Müller-Lyer (ML) illusion when the response is made after a brief period of visual occlusion. It is unclear whether this effect is due to (1) the elimination of on-line visual feedback, or (2) reliance on a stored perceptual representation of the target for movement planning. Here participants grasped objects from within two forms of a ML figure in four visual conditions (full vision, open-loop, brief delay, and 2-s delay) and estimated object size in the full-vision condition. Peak grasping aperture was influenced by the ML figure in the full-vision condition, although to a much smaller extent than was true for manual size estimation. The effect of the ML figure on peak grasping aperture was substantially increased in the open-loop and delay conditions, which did not differ from one another. These findings highlight the importance of on-line visual feedback for the resistance of grasping to the ML illusion and also call to attention the relevance of task factors such as target previewing, the visuomotor relevance of illusion-inducing elements, and participant strategies.

Transitive gesture production in apraxia: visual and nonvisual sensory contributions.

The production of transitive limb gestures is optimized when the appropriate tool can be physically manipulated. Little research has addressed the independent contributions of visual and nonvisual sources of sensory information to this phenomenon. In this study, 12 control, 37 LHD, and 50 RHD stroke patients performed transitive limb gestures to pantomime (to verbal command with the object visible) and object manipulation. Performance was more accurate in the object manipulation condition, suggesting that haptic and kinesthetic cues are important for transitive gesture production. Various patterns of performance were observed in the stroke groups, indicating that selective damage to the haptic/kinesthetic processing system is possible and common following unilateral stroke.

Memory for kinesthetically defined target location: evidence for manual asymmetries.

Sixteen right-handed male adults performed a pointing task without vision. The participant's arm was moved passively to one of four targets which was subsequently pointed to following a delay of 1, 2, or 10 s. Our previous research on visual memory for target location showed a rapid decay which was comparable for both hands. The present study of memory for kinesthetic target location found decay for the left hand only. These findings suggest two memory stores for target location information, one visual which decays over time but is accessible to both hands and another based on kinesthetic information which is more stable and limb specific.

Intransitive limb gestures and apraxia following unilateral stroke.

Apraxia is the loss of the ability to perform learned, skilled movements correctly, and is frequently attributed to left hemisphere damage (Heilman & Rothi, 1985). Recent work (Dumont, Ska, & Schiavetto, 1999) has shown a dissociation between transitive (tool based; e.g., hammering a nail) and intransitive (expressive/ communicative; e.g., waving goodbye) actions; however, few group studies have specifically addressed apraxia for intransitive gestures. The present investigation examined the frequency and severity of praxis errors related to the production of intransitive gestures in left (LHD) or right hemisphere stroke (RHD) patients in the context of Roy's (1996) model of limb praxis. A total of 119 consecutive stroke patients (LHD = 57, RHD = 62) and 20 healthy age-matched controls performed eight intransitive gestures to pantomime and imitation. Performance was quantified via a multi-dimensional error notation system, providing detail about specific elements of performance (e.g., location), and a composite score reflecting overall gestural accuracy. Analyses of pantomime and imitation performance revealed an equal percentage of apraxic patients in each stroke group, and the severity of apraxia in these groups was also equivalent. Further, analyses of the patterns of apraxia specified by Roy (1996) revealed that patients in each stroke group demonstrated selective impairments in pantomime (LHD = 38%, RHD = 42%), or imitation (LHD = 9%, RHD = 5%) conditions, whereas others demonstrated concurrent impairments (LHD = 30%, RHD = 22%) indicating that stroke to either hemisphere can selectively impair each stage in the production of an intransitive action.

The accuracy of reaching movements in brief delay conditions.

We tested the hypothesis that a highly accurate target representation is available to the visuomotor system in brief (< 2 s) delay conditions. Participants reached to single midsagittal targets (20, 25, 30, 35, 40 cm amplitude) in full vision, open-loop and delay conditions (500, 1,000, 1,500 or 2,000 ms). Radial endpoint error was significantly greater for open-loop than full vision reaches, and was greater still for all delay conditions, which did not differ from one another. Radial error was greater for farther targets, although this tended to hold only for delayed reaches. These data suggest that the visuomotor system switches from on-line visual information to a degraded, stored representation very soon (< 500 ms) if not immediately after target occlusion.

The effect of a pictorial illusion on closed-loop and open-loop prehension.

It has been proposed that movements to visible and remembered targets are sensitive to qualitatively different types of visual information. When the target is continuously visible, prehensile movements are thought to reflect veridical object size, whereas memory-dependent prehension is sensitive to the perceived size of the object. This hypothesis was explored by assessing the influence of illusory target width on prehension kinematics in three visual conditions: closed-loop (CL; full vision during the response), open-loop brief-delay (OL; visual occlusion coincident with the movement initiation cue) and open-loop 3-s delay (OL3; visual occlusion 3 s prior to movement initiation). To modulate illusory target width, objects were placed on backgrounds consisting of three forms of the Müller-Lyer (ML) figure. Peak grip aperture was sensitive to the ML figure in the OL and OL3, but not CL conditions, suggesting that perceptual information is used to modulate this grasping parameter when the movement is programmed and executed on the basis of visual memory. Peak-aperture velocity was affected by the ML illusion in all three visual conditions, suggesting that perceived object size might be important for modulating this aspect of prehension, independent of memory requirements. The different sensitivity of grip aperture and aperture velocity to illusory target width in the CL condition suggests that grasp preshaping might reflect multiple visuomotor processes. The results of this study are consistent with the tenets of the two-stream model of visual processing.

Posture and target location effects on manual preference.

Twenty-nine right-handed participants made unimanual movements to 5 target locations while standing and while balancing on a rocker platform. Manual preference was affected by target location (p < .001; manual preference tended to be concordant with target hemispace) and posture (p < .05; responses from the rocker platform were associated with a lower level of right-hand responding). A location by posture interaction (p < .05) indicated that the effect of posture was present only for targets in left hemispace; the right hand was used less frequently in the rocker condition than simple standing. Manual preference is viewed as a process of response selection motivated by an effort to minimize neural processing and mechanical costs.