This has come up in Question 2 from the second paper of 2014. Apart from neurosurgical options the College wanted their candidates to discuss blood pressure management, therapeutic hypothermia, likely prognosis and quality of life issues. Judging from the model answer, some detailed knowledge of the published trial evidence was expected.
A section of Oh's manual is dedicated to this exact issue. Chapter 51 ("Acute cerebrovascular complications") by Bernard Riley and Thearina de Beer contains within it a few paragraphs on decompressive craniectomy, on page 571. It would be worth pointing out that the key issues raised in these paragraphs were also raised in the model answer, and one would be well advised to review this material in order to produce an answer which appeases the examiners. For all we know, Riley or de Beer wrote that SAQ.
Apart from the brief entry in Oh's, several excellent resources exist for this topic:
If one were to discuss or critically evaluate the use of decompressive craniectomy in stroke, one would go about it in a systematic fashion:
The college model answer lists three landmark studies worth referencing, which form the three famous European hemicraniectomy trials. They were HAMLET, DESTINY and DECIMAL.
A pooled analysis of the first three studies, including 93 patient cases, came to a fairly positive conclusion:
"...after decompressive surgery the probability of survival increases from 28% to nearly 80% and the probability of survival with an mRS of ≤3 doubles."
(mRS here being the score of the modified Rankin scale, equating to a disability where one requires some help, some of the time, with some things - but is otherwise able to walk unassisted).
In addition to the above studies, the college mentions that people in the over-60s age group are also being investigated as potential candidates for decompressive craniectomy.
They were probably referring to the DESTINY II Trial (2014):
These are the findings from the three abovementioned European trials.
Chapter 51 (pp. 568) Acute cerebrovascular complications by Bernard Riley and Thearina de Beer
Torbey, Michel T., et al. "Evidence-Based Guidelines for the Management of Large Hemispheric Infarction." Neurocritical care (2015): 1-19.
Wartenberg, Katja E. "Malignant middle cerebral artery infarction." Current opinion in critical care 18.2 (2012): 152-163.
Yang, Ming-Hao, et al. "Decompressive hemicraniectomy in patients with malignant middle cerebral artery infarction: A systematic review and meta-analysis." The Surgeon (2015).
Jüttler, Eric, et al. "Decompressive surgery for the treatment of malignant infarction of the middle cerebral artery (DESTINY) a randomized, controlled trial." Stroke 38.9 (2007): 2518-2525.
Jüttler, Eric, et al. "DESTINY II: DEcompressive Surgery for the Treatment of malignant INfarction of the middle cerebral arterY II." International Journal of Stroke 6.1 (2011): 79-86.
Vahedi, Katayoun, et al. "Sequential-design, multicenter, randomized, controlled trial of early decompressive craniectomy in malignant middle cerebral artery infarction (DECIMAL Trial)." Stroke 38.9 (2007): 2506-2517.
Hofmeijer, Jeannette, et al. "Surgical decompression for space-occupying cerebral infarction (the Hemicraniectomy After Middle Cerebral Artery infarction with Life-threatening Edema Trial [HAMLET]): a multicentre, open, randomised trial." The Lancet Neurology 8.4 (2009): 326-333.
Vahedi, Katayoun, et al. "Early decompressive surgery in malignant infarction of the middle cerebral artery: a pooled analysis of three randomised controlled trials." The Lancet Neurology 6.3 (2007): 215-222.
Slotty, Philipp Jörg, et al. "The influence of decompressive craniectomy for major stroke on early cerebral perfusion." Journal of neurosurgery (2015): 1-6.
Barroso, Bruno. "Decompressive craniectomy for stroke after intravenous thrombolytic therapy." International Journal of Stroke 9.8 (2014): E40-E40.
Wijdicks, Eelco FM, et al. "Recommendations for the Management of Cerebral and Cerebellar Infarction With Swelling A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association." Stroke 45.4 (2014): 1222-1238.
Jüttler, Eric, et al. "Hemicraniectomy in older patients with extensive middle-cerebral-artery stroke." New England Journal of Medicine 370.12 (2014): 1091-1100.