Correspondence Evaluation of tissue oximetry in per io perat ive monit o ri ng of co Io recta I surgery
Technique for laparoscopic appendicectomy Sir
Sir
We read with interest the recent article by Van Esbroeck and colleagues on tissue oximetry in colorectal surgery (Br J Surg 1992; 79: 584-7). We wish to raise a number ofpoints about this paper. The introduction states that ‘subcutaneous tissue partial pressure of oxygen (P,,,,) . . . correlate(s) more accurately with haemodynamic status than traditional perfusion parameters’, but no reference is given to support this claim. In Patients and methods it is stated that gastric intramural pH (pH,) was measured according to the method of Fiddian-Green and Baker. The reference is not written exactly according to the guidelines laid down in the Journal’s Instructions to Authors, and the paper referenced does not describe the method of measuring pH,‘. In the next paragraph in the article, arterial hypoxaemia is defined as an arterial partial pressure of oxygen (Pzol) of 80mmHg or an oxygen saturation t 9 0 per cent. These values are not comparable: an oxygen saturation of 90 per cent’ would generally indicate a Pa,, of 60mmHg. The controls are not age matched with the patients, making comparison of tissue perfusion difficult.Was there an attempt to adjust statistically for age? In the Discussion it is stated that there was a significant difference between preoperative and postoperative PrsO2values, but the subcutaneous oximeters were inserted at the time of surgery, not before operation. Was there a significant difference between the complicated as this and uncomplicated patients in relation to postoperative ProO2, was not mentioned in the Results? We feel that this study (while conceptually important) should be of larger numbers, with appropriate matched controls, and have stratification of the complication endpoints before any valuable conclusion can be reached.
M. Sugrue A. Lee M. Buist Department of Surgery and Intensive Care Liverpool Hospital Sydney N S W 21 70 Australia
1. 2.
We read with interest the recent Surgical Workshop by Byrne and colleagues describing their technique for laparoscopic appendicectomy (Br J Surg 1992; 79: 574-5). We use a similar technique and support their assertion that laparoscopically guided dissection and delivery of the appendix on to the abdominal surface is safe and can be learned quickly. Our technique is different in two important ways. First, we deliver the appendix through a standard non-disposable 10-mm trocar and cannula. Second, we ligate the appendix stump and vessels, and never use staplers. We believe that employing disposable trocars and cannulas and the use of stapling devices defeats the major financial advantage of this technique for appendicectomy over intra-abdominal procedures, which involve the use of endo-clips and endo-staplers. The technique described by Byrne and colleagues uses at least one disposable trocar and cannula (perhaps two - their article does not make it clear) and one TA30 stapler (Auto Suture, Ascot, UK). The extra cost of disposables when compared with conventional open appendicectomy is well over f 100 and is an important objection to their method. We have noted that once the appendix is withdrawn through the cannula, it can be difficult to identify the junction between appendix and caecum. With traction on the appendix, the caecum can be ‘tented’ and we have on one occasion inadvertently tied the caecum. We now mark the proposed site of appendix ligation by briefly touching the appendix with diathermy. Once the appendix is delivered, it is easy to identify the serosal diathermy mark. We inspect the caecum and appendix stump within the abdominal cavity, after appendicectomy, confirming that all the ligatures are secure. We recommend our modifications: costly disposables are not used, ligatures are easily tied on the abdominal surface and the site of appendix ligation can be confidently identified.
H. Cajraj A. El-Din C. McGuiness A. Choy St Helier NHS Trust Hospital Carshalton Surrey SM5 IAA
Fiddian-Green RG, Baker S. Predictive value of the stomach wall pH for complications after cardiac operations: comparison with other monitoring. Crir Care Med 1987; 15: 153-6. Ganong WF. Gas transport between lung and tissue. In: Ganong WF, ed. Review of MedicalPhysiology. Los Altos: Lange Medical, 1981: 52C-6.
Authors’ reply
UK
Cholecystectomy and gallbladder conservation
Sir
Sir
We thank Mr Sugrue and co-workers for their interest in our paper. They suggest that we stated that there was a significant difference between preoperative and postoperative subcutaneous partial pressure of oxygen values. Careful reading shows that this is not the case. Measurements were made only in the peroperative and postoperative periods; this was clearly stated. Moreover, one of the most puzzling results of our study is that there is a significant difference between peroperative subcutaneous oxygen tensions of the uncomplicated and complicated patient groups. There was no such difference after operation. One might almost suggest that the patients had their postoperative complications in the operating theatre. If peripheral tissue oximetry is made simpler and quicker to perform, larger numbers of patients will indeed be studied with appropriate matched controls.
We agree entirely with the suggestion of Messrs Walsh and Russell (Br J Surg 1992; 79: 4-5) that gallbladder conservation is a desirable option in the management of gallbladder stone disease and have read with interest Mr Salam’s comments ( B r JSurg 1992; 79: 713) regarding laparoscopic cholecystotomy and stone removal. Surgical laparoscopy requires general anaesthesia and a formal pneumoperitoneum, and whether this is ‘minimallyinvasive’is open to debate. We have described a simple and safe technique for gallstone removal under local or regional anaesthesia’. The whole procedure is conducted under direct vision and the complications of a ‘blind’entry into the peritoneum are also avoided. We agree with Mr Salam’s suggestion that gallbladder conservation in contracting gallbladders be compared with cholecystectomy, as the incidence of stone recurrence may not be nearly as high as is often assumed’.
C. Van Esbroeck T. Cys A. Hubens Department of General Surgery Stuivenberg General Hospital University of Antwerp 2060 Antwerp Belgium
1246
A. W. Majeed M. W. R. Reed A. G. Johnson University Surgical Unit Royal Hallamshire Hospital Shefield SIO 2JF
UK
Br. J. Surg., Vol. 79, No. 11. November 1992
Technique for laparoscopic appendicectomy Sir
Sir
We read with interest the recent article by Van Esbroeck and colleagues on tissue oximetry in colorectal surgery (Br J Surg 1992; 79: 584-7). We wish to raise a number ofpoints about this paper. The introduction states that ‘subcutaneous tissue partial pressure of oxygen (P,,,,) . . . correlate(s) more accurately with haemodynamic status than traditional perfusion parameters’, but no reference is given to support this claim. In Patients and methods it is stated that gastric intramural pH (pH,) was measured according to the method of Fiddian-Green and Baker. The reference is not written exactly according to the guidelines laid down in the Journal’s Instructions to Authors, and the paper referenced does not describe the method of measuring pH,‘. In the next paragraph in the article, arterial hypoxaemia is defined as an arterial partial pressure of oxygen (Pzol) of 80mmHg or an oxygen saturation t 9 0 per cent. These values are not comparable: an oxygen saturation of 90 per cent’ would generally indicate a Pa,, of 60mmHg. The controls are not age matched with the patients, making comparison of tissue perfusion difficult.Was there an attempt to adjust statistically for age? In the Discussion it is stated that there was a significant difference between preoperative and postoperative PrsO2values, but the subcutaneous oximeters were inserted at the time of surgery, not before operation. Was there a significant difference between the complicated as this and uncomplicated patients in relation to postoperative ProO2, was not mentioned in the Results? We feel that this study (while conceptually important) should be of larger numbers, with appropriate matched controls, and have stratification of the complication endpoints before any valuable conclusion can be reached.
M. Sugrue A. Lee M. Buist Department of Surgery and Intensive Care Liverpool Hospital Sydney N S W 21 70 Australia
1. 2.
We read with interest the recent Surgical Workshop by Byrne and colleagues describing their technique for laparoscopic appendicectomy (Br J Surg 1992; 79: 574-5). We use a similar technique and support their assertion that laparoscopically guided dissection and delivery of the appendix on to the abdominal surface is safe and can be learned quickly. Our technique is different in two important ways. First, we deliver the appendix through a standard non-disposable 10-mm trocar and cannula. Second, we ligate the appendix stump and vessels, and never use staplers. We believe that employing disposable trocars and cannulas and the use of stapling devices defeats the major financial advantage of this technique for appendicectomy over intra-abdominal procedures, which involve the use of endo-clips and endo-staplers. The technique described by Byrne and colleagues uses at least one disposable trocar and cannula (perhaps two - their article does not make it clear) and one TA30 stapler (Auto Suture, Ascot, UK). The extra cost of disposables when compared with conventional open appendicectomy is well over f 100 and is an important objection to their method. We have noted that once the appendix is withdrawn through the cannula, it can be difficult to identify the junction between appendix and caecum. With traction on the appendix, the caecum can be ‘tented’ and we have on one occasion inadvertently tied the caecum. We now mark the proposed site of appendix ligation by briefly touching the appendix with diathermy. Once the appendix is delivered, it is easy to identify the serosal diathermy mark. We inspect the caecum and appendix stump within the abdominal cavity, after appendicectomy, confirming that all the ligatures are secure. We recommend our modifications: costly disposables are not used, ligatures are easily tied on the abdominal surface and the site of appendix ligation can be confidently identified.
H. Cajraj A. El-Din C. McGuiness A. Choy St Helier NHS Trust Hospital Carshalton Surrey SM5 IAA
Fiddian-Green RG, Baker S. Predictive value of the stomach wall pH for complications after cardiac operations: comparison with other monitoring. Crir Care Med 1987; 15: 153-6. Ganong WF. Gas transport between lung and tissue. In: Ganong WF, ed. Review of MedicalPhysiology. Los Altos: Lange Medical, 1981: 52C-6.
Authors’ reply
UK
Cholecystectomy and gallbladder conservation
Sir
Sir
We thank Mr Sugrue and co-workers for their interest in our paper. They suggest that we stated that there was a significant difference between preoperative and postoperative subcutaneous partial pressure of oxygen values. Careful reading shows that this is not the case. Measurements were made only in the peroperative and postoperative periods; this was clearly stated. Moreover, one of the most puzzling results of our study is that there is a significant difference between peroperative subcutaneous oxygen tensions of the uncomplicated and complicated patient groups. There was no such difference after operation. One might almost suggest that the patients had their postoperative complications in the operating theatre. If peripheral tissue oximetry is made simpler and quicker to perform, larger numbers of patients will indeed be studied with appropriate matched controls.
We agree entirely with the suggestion of Messrs Walsh and Russell (Br J Surg 1992; 79: 4-5) that gallbladder conservation is a desirable option in the management of gallbladder stone disease and have read with interest Mr Salam’s comments ( B r JSurg 1992; 79: 713) regarding laparoscopic cholecystotomy and stone removal. Surgical laparoscopy requires general anaesthesia and a formal pneumoperitoneum, and whether this is ‘minimallyinvasive’is open to debate. We have described a simple and safe technique for gallstone removal under local or regional anaesthesia’. The whole procedure is conducted under direct vision and the complications of a ‘blind’entry into the peritoneum are also avoided. We agree with Mr Salam’s suggestion that gallbladder conservation in contracting gallbladders be compared with cholecystectomy, as the incidence of stone recurrence may not be nearly as high as is often assumed’.
C. Van Esbroeck T. Cys A. Hubens Department of General Surgery Stuivenberg General Hospital University of Antwerp 2060 Antwerp Belgium
1246
A. W. Majeed M. W. R. Reed A. G. Johnson University Surgical Unit Royal Hallamshire Hospital Shefield SIO 2JF
UK
Br. J. Surg., Vol. 79, No. 11. November 1992
